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Feijoa [Acca sellowiana (O. Berg) Burret] pollination: A review
Abstract
Pollination is a key reproductive event conducive to fruit set in Feijoa (Acca sellowiana). Flowers are uniflorous, often forming clusters and hermaphrodite, bearing stamens and one elongated carpel. Stamens are numerous ranging from 60 to 120 per flower depending on cultivar. Flowers do not produce nectar. Pollen grains are small with average size of 10–28 μm in diameter. Some cultivars bear barriers to self-fertilization e.g. self-incompatibility and dichogamy by protogyny. Feijoa can be self-pollinated and able to set fruit, or partially, self-fertile. Wind is a possible pollination agent, but more research is required to confirm it as a vector. Cross-pollination occurs among different cultivars. Birds are also reported as important pollinators. Muscicapidae, Turdidae and Thraupidae bird families are important floral visitors. Birds feed on feijoa petals and transfer pollen grains from their body parts to stigma, promoting pollination. Insects, particularly bees are also reported to be pollinators. However, this again is controversial. The small body of bees is unable to establish contact with the stigmatic surface. Experimental pollen germination, viability and tube growth are dependent on cultivar and culture media conditions. Few studies have been conducted on pollen germination. This review seeks to expand the current information on feijoa pollination in tropical and subtropical environments. It is expected that this review will be useful to senior researchers, undergraduate students, growers and the general public.
... The hermaphrodite flowers of 3-4 cm are composed of four greenish-gray sepals and a corolla formed of four white petals. In the center, there are 60-120 stamens of red filaments with white anthers, according to the particular cultivar (Fischer, 2003;Ramírez & Kallarackal, 2017). In general, A. sellowiana has barriers to self-fertilization such as the dichogamy through protogyny and self-incompatibility (Stewart & Craig, 1987), and Finatto et al. (2011) found a late-acting self-incompatibility in this species. ...
... Many cultivars are self-fertile, but they also allow crosspollination by insects or birds (Ramírez & Kallarackal, 2017). The most important ornithological agent in Colombia is the blackbird (Turdus fuscater), Turdus merula in New Zealand and Acridotheres tristis, and Turdus spp., Thraupis spp. ...
... Flowering and ripening of the fruit can be advanced by eight weeks in warmer climates compared to cold climates (Duarte & Paull, 2015). Furthermore, climate change impacts tree phenology (Ramírez & Kallarackal, 2017). However, fruits produced in cold weather are supposedly of better flavor than those produced in hot climates (California Rare Fruit Growers, 1996). ...
Climatic alterations affect the physiology, growth and production of the feijoa, a native plant to the higher zone between Brazil, Uruguay, Paraguay and Argentina. In Colombia, optimal growth temperatures are between 13 and 21°C (16°C). Very high temperatures (>32°C) affect pollination and fruit set, but low temperatures down to -4°C in adult plants do not cause significant damage. Thus, feijoa is a well-adapted plant to cold conditions since 3.04°C has been found as the base (minimum) temperature for the phase between flower bud and fruit set, while 1.76°C was measured as the base temperature for fruit development. The plant requires a minimum of 1000 hours of direct sunlight/year (optimum≥1500); the pyramidal form of the tree favors the entry of light into the crown organs. In the crown of a feijoa tree, trained with three branching levels of horizontal bent primary laterals, the outer middle quadrant produces the largest fruits, compared to those that grow in the upper quadrant. The reduced fruit growth is due to the excessive incidence of light (especially UV) and heat on these fruits on the periphery of the tree. In Colombia, altitudes between 1800 and 2700 meters above sea level (m a.s.l.) are adequate for growth and production of this fruit, while lower elevations favor the incidence of fruit flies. Precipitations between 700 and 1200 mm/year (max. 2000 mm) benefit the vegetative and reproductive performance of the tree, with an important drier season at the beginning of the reproductive season (flowering and fruit set). Due to the strength of its branches and the small, thick leaves, the tree is relatively wind resistant.
... Fruit trees require pollination for fruit development. Pollination in woody angiosperms has been studied in several tropical, temperate and subtropical fruit tree species Davenport 2013, 2016;Ramírez and Kallarackal 2017) as well as in wild species. They include almond (Klein et al. 2012), apricot (Langridge and Goodman 1981), apple , cherry (Holzschuh et al. 2012), carambola (Rodger et al. 2004, coconut (Melendez-Ramirez et al. 2004), litchi (Pandey andYadava 1970), loquat (Cuevas et al. 2003), mango , pear (Monzón et al. 2004), citrus (Davenport 1986), avocado (Vithanage 1990), etc. Fruit crops are an important food and health source for humans worldwide. ...
... For example, 'Kent' mango (Mangifera indica L.) trees require an optimum temperature of 30 °C for effective pollen germination (Dag et al. 2000). Pollination is highly sensitive to temperature extremes across all species, having a negative impact on production (Hatfield and Prueger 2015;Ramírez and Kallarackal 2017). Either high or low temperatures are known to affect the pollination physiology of trees. ...
... Moreover, higher than normal temperature (33 °C day/28 °C night) conditions during flowering have been known to cause floral abscission and ovule damage in avocado (Sedgley 1977;Argaman 1983;Davenport 1986). In vitro feijoa (Acca sellowiana) pollen germination was lower at 30 °C (Franzon et al. 2005;Ramírez and Kallarackal 2017). Pollen germination was halted at 45 °C in sugar apple (Rodrigues et al. 2016). ...
This brief reviews the pollination aspects of both wild and domesticated fruit tree species in a global climate change context. It explores cross-pollination mediated by insects, vertebrates and abiotic factors, self-pollination and their global warming implications. The authors identify the link between abiotic factors such as precipitation and severe droughts in the context of tree pollination and climate change. Furthermore, pollination and conservation implications in agriculture as well as wild tree populations are explored. Emphasis has been given to fruit trees growing in tropical, subtropical and temperate environments.
... (Ducroquet et al. 2000; Thorp & Bieleski 2002). The guava presents hermaphrodite and longistillate flowers, with four green and tomentose sepals and 4 to 5 fleshy white petals, reddish on the underside, with numerous stamens and this flowers do not produce nectar (Ducroquet & Hickel 1997;Roig 1992;Ducroquet et al. 2000;Ramírez & Kallarackal 2017). ...
... Patterson (1990) also indicate that cross-fertilization ensures a greater quantity and quality of fruits. The most important pollinating agents are birds and insects (Ramírez & Kallarackal, 2017). The birds pollinate and eat the petals, preventing the proliferation of diseases (Quintero, 2012) Ducroquet et al. (2000 estimated that about 25% fruit set may be due to entomophilic pollination. ...
The Feijoa “Guayabo del país” (Acca sellowiana) is a native Myrtaceae whose fruits have a great commercial potential for their nutritive properties. The objectives of this study were to determine the extent to which fruit production depends on biotic pollination and to identify potential pollinators in Uruguay. Two farms and three park, located in Salto and Canelones were used for the study. The percentage of fruit set in the branches excluding pollinators did not exceed 5.1%, whereas in the branches with free access of pollinators it varied between 10.4% (Salto) and 90.9% (park trees, Canelones). A total of 28 insect species and 3 Passeriforme species were identified on the flower varying with the region. Apis mellifera were present on all plantations with high frequency. Remarkably, 7 species of native bees and 3 species of native passerines were found only in the southern trees of the country. Some pollinators can be managed to improve production, of commercial quality, like honeybees or bumblebees.
... These morphological and behavioral traits probably constitute the underlying mechanisms explaining the positive association between blueberry fruit size and abundance of hummingbirds and big-sized bees. Indeed, since vertebrates pollinate very few economically relevant crops, (e.g., durian (Bumrungsri et al., 2009), agave (Trejo-Salazar et al., 2016, and feijoa (Ramírez and Kallarackal, 2017)), we believe that our findings regarding the benefits of hummingbirds to blueberry production deserve to be highlighted. To our knowledge, only one study described hummingbirds as pollinators of a flowering crop (coffee) in Central America (Barney, 2019). ...
... That study described interaction events, but not the potential consequence in crop productivity metrics. Therefore, ours constitutes one of those unique systems where birds contribute significantly to the pollination and, potentially, the production of a flowering crop (Klein et al., 2007;Ramírez and Kallarackal, 2017). Either that, or the role of hummingbirds in crop pollination needs to be more carefully assessed across different crops. ...
The contribution of wild pollination service to global agriculture is increasingly recognized. Still, biotic pollination demand is mainly covered by managed species, whereas implementing ecological intensification practices to promote wild pollination service remain less common. In this study, we evaluated (i) the effect of wild and managed pollinators and the richness of pollinator functional groups (RPFG) on production quality (i.e., fruit size) and quantity (i.e., crop yield), of two southern highbush blueberry (Vaccinium corymbosum) cultivars, and (ii) how wild pollinator service and crop production correlate with farm’s land cover. We found that pollination service supply and the spatial context interact with the blueberry cultivar to determine yield and fruit size. The abundance of big-sized wild bees and hummingbirds positively affected fruit size and crop yield, but the relationship's significance was cultivar-dependent. In contrast, the increase in honeybees visitation rate was detrimental to the average fruit size of blueberries, but the effect was not generalizable between cultivars. The amount of forested area affected positively wild pollinator abundance and RPFG only in one cultivar, whereas grassland and hedgerow had adverse effects for pollinators in the other. Consistently, the relation between blueberry fruit size and the farm’s land cover was subordinate to the cultivar. That is, despite all significant relations had the same sign between cultivars, their coefficients were statistically different. Our results support the idea that wild pollinators contribute to producing higher yields and larger berries in blueberry crops. Moreover, we found that the retention of natural forest at a 200 m radius within the farm may increase pollination service supply. However, the significance of every effect was contingent on the blueberry cultivar. This cultivar-dependent response points out that a robust assessment of pollinator benefits not only should include multiple production metrics, but also must incorporate within-crop variation, particularly in systems where growers use a mosaic of cultivars with different pollination requirements.
... The development of new cultivars with superior fruit quality traits and adapted for new environments is needed to accelerate the commercial exploitation of this species. Genetic variability of this species is maintained in germplasm collections around the world such as the Feijoa Active Germplasm Bank (BAG) in Sao Joaquim-SC (Brazil), the National Feijoa Center (CENAF) in La Vega (Cundinamarca, Co- Flowering period occurs in spring, but it is variable depending on the cultivars and environmental conditions [13] ( Figure 1B). In the Mediterranean area, floral development and emergence last for two months (Mid-April to June) and this was also confirmed in Chinese feijoa orchards by Zou et al. [14]. ...
... In the Mediterranean area, floral development and emergence last for two months (Mid-April to June) and this was also confirmed in Chinese feijoa orchards by Zou et al. [14]. Feijoa cultivars bear different barriers to self-Agronomy 2022, 12, 1802 3 of 14 fertilization, some of them are strictly self-incompatible, while others are compatible or partially compatible [13]. Cross-pollination increases a fruit set up to 80-90%, while selfpollination halves it; this is due to a higher percentage of abscission in self-pollinated than in cross-pollinated flowers [15]. ...
Feijoa (Acca sellowiana (O. Berg) Burret syn Feijoa sellowiana Berg) is a monotypic species belonging to the Myrtaceae family. Feijoa is cultivated in different countries, and it is mainly consumed as fresh fruit, due to its attractive nutritional quality, nevertheless, several feijoa-based products have been produced and are available in some niche and local markets. The fruits are not the only edible part of the tree since petals of hermaphrodite showy flowers can also be eaten. Fruits are rich in vitamin C, fiber, potassium, iodine, phosphorus, sugars, and calcium. In addition, a large number of bioactive compounds, with many health-promoting benefits, have been identified. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the knowledge on feijoa, evaluating the main agronomic, qualitative, and nutraceutical traits of its edible parts. Moreover, the variability in feijoa genetic resources to identify and select promising genotypes useful for breeding programs and the postharvest management of fruit and edible flowers will be discussed. Overall, feijoa has great potential to be considered as a sustainable fruit crop from farm to table.
... C. Ballesteros and H. M. Puerto, personal communication, 2019). This tree is Acca sellowiana (Myrtaceae), commonly known in the region as feijoa, a nonnative cultivated fruit plant from northern Argentina and Uruguay and southern Brazil (Keller & Tressens, 2007) that has been introduced in different countries due to its important economic value (Ramírez & Kallarackal, 2017). In Colombia, A. sellowiana is cultivated in several regions located in higher altitudes with colder climates, such as in the Boyac a department. ...
... A. sellowiana flowers have fleshy white petals with a purple interior, with many red stamens and an upright red central pistil located above (Figure 1a). The pollination process is unusual since the energy-rich petals are the resource being consumed by birds that are the main pollinators (Ramírez & Kallarackal, 2017). In several Colombian cities, A. sellowiana is cultivated in urban areas. ...
... Berg) Burret stands out for its high value of bioactive compounds from fruits and food products (Vuotto et al., 2000). A. sellowiana is native to southern Brazil, Argentina, Uruguay and Paraguay (Ramírez;Kallarackal, 2017), belonging to the Myrtaceae family which has a predominantly pantropical and subtropical distribution, concentrated in the Neotropical region and in Australia. Feijoa fruit is sweet/sour and highly aromatic. ...
... Berg) Burret stands out for its high value of bioactive compounds from fruits and food products (Vuotto et al., 2000). A. sellowiana is native to southern Brazil, Argentina, Uruguay and Paraguay (Ramírez;Kallarackal, 2017), belonging to the Myrtaceae family which has a predominantly pantropical and subtropical distribution, concentrated in the Neotropical region and in Australia. Feijoa fruit is sweet/sour and highly aromatic. ...
... Prašnici cvijeta stoje samo četiri dana. Cvjetovi se postupno otvaraju pa i sama cvatnja traje duže, u idealnim uvjetima od 50-60 dana (Ramírez & Kallarackal, 2017.). ...
... Plod čini bijelo aromatično meso, zrnaste strukture i slatko-kiselkastog okusa koje predstavlja i do 50% udjela ploda Biološki ciklus feijoe ovisi o klimatskim, edafskim i orografskim čimbenicima. U zemljama sjeverne polutke, ova voćna vrsta cvjeta u proljeće, a plodovi dozrijevaju tijekom listopada i studenog (Ramírez & Kallarackal, 2017.). Klimatski uvjeti s blagim zimama i temperaturama od 13-21 °C smatraju se najprikladniji za uzgoj ove vrste. ...
Feijoa, Acca Sellowiana (O.Berg.) O. Berg is a subtropical fruit from the Myrtaceae family. It is grown all over the world, but in Croatia, it is the least represented type of fruit. Feijoa is mainly propagated generative by. In the Institute for Mediterranean plants, the previous experiences of propagating feijoa by cuttings did not give the best results. Therefore, the goal of this study was to determine the rooting of Feijoa cuttings treated with different concentrations of indole-butyric acid (IBA) phytohormone with respect to the time of taking the cuttings. The research took two years, and semi-woody
and woody cuttings were used. The basal part of cuttings was treated with different concentrations of phytohormone IBA (1500, 2000, 2500, 3000 ppm). The results show
the best rooting of semi-mature cuttings at a concentration of 2500 ppm, with 32%
success.
... La razón es la alta autoincompatibilidad de muchas variedades de feijoa (Thorp, 2008). Por ejemplo "Mammoth" es considerado autofértil debido a su porcentaje de cuajamiento de frutos (55 %), al contrario de "Triumph", que muestra una barrera para su autopolinización (Ramírez & Kallarackal, 2017). Quintero (2012) reportó que la polinización cruzada puede aumentar el porcentaje de frutos cuajados, entre un 80 y 90 %, comparado con la autofecundación que produce apenas la mitad de los cuajados. ...
... Los agentes polinizadores más importante son los pájaros y en menor grado los insectos (Ramírez & Kallarackal, 2017). Los pájaros no solamente polinizan sino también comen toda la corola lo que evita la proliferación de Botrytis cinerea (Quintero, 2012). ...
La feijoa es un frutal con gran potencial para el consumo humano, que se cultiva entre los 1800 y 2700 msnm en Colombia. Está bien adaptada a temperaturas bajas, resistiendo por corto tiempo temperaturas <0 °C, mientras que temperaturas >32 °C afectan su floración. La temperatura base para botón floral a antesis es 2,89 °C, de antesis a cuajamiento del fruto es de 3,04 °C y del cuajamiento del fruto a cosecha, 1,76 °C. El árbol crece muy bien en suelos aluviales, profundos y ricos en materia orgánica. En la poda del árbol es importante la formación en cono con tres niveles de ramas agobiadas y la eliminación de los chupones, para fomentar así la floración y la longevidad del árbol. En los pocos estudios fisiológicos se encontró una tasa fotosintética baja (en promedio entre 4 y 6 μmol CO 2 m-2 s-1), con gran demanda energética durante la floración, mientras la transpiración aumenta con la irradiancia, la temperatura y la disminución de la humedad relativa, mostrando un mayor número de estomas foliares en el estrato superior de la copa (91/mm 2), comparado con el inferior (78/mm 2). El inicio de la etapa reproductiva está favorecida por las condiciones más secas y por la fertilización con KH 2 PO 4 al 0.5 %. En Colombia, frutos de mayor calibre y producciones más altas se logran a través de la polinización por la mirla negra (Turdus fuscater). El fruto necesita entre 120 y 150 días para desarrollarse y se presentan producciones entre 30 y 40 kg/árbol (≥20 t ha-1). El color verde del fruto en todos sus estados dificulta la determinación del grado de madurez.
Abstract Feijoa is a fruit tree with great potential for human consumption, cultivated between 1,800 and 2,700 m.a.s.l. in Colombia. It is well adapted to cold temperatures, resisting temperatures <0 °C for a short time, while temperatures >32 °C affect its flowering. It has base temperatures for its state from flower bud to anthesis with 2.89 °C, from anthesis to fruit set with 3.04 °C and from fruit set to harvest 1.76 °C. The tree thrives well in in alluvial soils, deep and rich in organic matter ones. In the tree pruning, the cone formation with three levels of horizontal bent branches and the elimination of suckers are important, thus promoting flowering and longevity of the tree. In the few physiological studies, a low photosynthetic rate (on average between 4 and 6 μmol CO 2 m-2 s-1) was found, with high energy demand during flowering, while the transpiration rate of the crown increases with irradiance, temperature and the decrease in relative humidity, showing a greater number of leaf stomata in the upper layer of the crown (91/mm 2), compared to the lower layer (78/mm 2). The beginning of the reproductive stage is favored by dry conditions, as well as potassium fertilization with 0.5% KH 2 PO 4. In Colombia, fruits of greater caliber and higher productions are achieved through cross-pollination by blackbirds (Turdus fuscater). The fruit needs about 120 to 150 days to develop and there are productions between 30 and 40 kg/tree (≥20 t ha-1). The green color of the fruit in all its stages makes it difficult to determine its maturity state.
... La razón es la alta autoincompatibilidad de muchas variedades de feijoa (Thorp, 2008). Por ejemplo "Mammoth" es considerado autofértil debido a su porcentaje de cuajamiento de frutos (55 %), al contrario de "Triumph", que muestra una barrera para su autopolinización (Ramírez & Kallarackal, 2017). Quintero (2012) reportó que la polinización cruzada puede aumentar el porcentaje de frutos cuajados, entre un 80 y 90 %, comparado con la autofecundación que produce apenas la mitad de los cuajados. ...
... Los agentes polinizadores más importante son los pájaros y en menor grado los insectos (Ramírez & Kallarackal, 2017). Los pájaros no solamente polinizan sino también comen toda la corola lo que evita la proliferación de Botrytis cinerea (Quintero, 2012). ...
La feijoa es un frutal con gran potencial para el consumo humano, que se cultiva entre los 1800 y 2700 msnm en Colombia. Está bien adaptada a temperaturas bajas, resistiendo por corto tiempo temperaturas <0 °C, mientras que temperaturas >32 °C afectan su floración. La temperatura base para botón floral a antesis es 2,89 °C, de antesis a cuajamiento del fruto es de 3,04 °C y del cuajamiento del fruto a cosecha, 1,76 °C. El árbol crece muy bien en suelos aluviales, profundos y ricos en materia orgánica. En la poda del árbol es importante la formación en cono con tres niveles de ramas agobiadas y la eliminación de los chupones, para fomentar así la floración y la longevidad del árbol. En los pocos estudios fisiológicos se encontró una tasa fotosintética baja (en promedio entre 4 y 6 μmol CO2 m-2 s-1), con gran demanda energética durante la floración, mientras la transpiración aumenta con la irradiancia, la temperatura y la disminución de la humedad relativa, mostrando un mayor número de estomas foliares en el estrato superior de la copa (91/mm2), comparado con el inferior (78/mm2). El inicio de la etapa reproductiva está favorecida por las condiciones más secas y por la fertilización con KH2PO4 al 0.5 %. En Colombia, frutos de mayor calibre y producciones más altas se logran a través de la polinización por la mirla negra (Turdus fuscater). El fruto necesita entre 120 y 150 días para desarrollarse y se presentan producciones entre 30 y 40 kg/árbol (≥20 t ha-1). El color verde del fruto en todos sus estados dificulta la determinación del grado de madurez.
... The petals show a form from suborbicular to elliptic and their numbers range from four to six with a fleshy texture and sweet taste. Indeed, they can be used in salads, infusions, or as food decorations [3,4]. Edible flowers have been used in various ancient cultures such as Greece, Rome, India, and China for their beneficial, nutritional, and medicinal properties [5,6]. ...
... Feijoa flower opening has a short lifespan, of about eight days, and it is a scalar process where not all flowers open at the same time [4]. The reactive oxygen species (ROS) are generally toxic for plants and they can cause damage to different biomolecules [52]. ...
Background:
Feijoa (Acca sellowiana (O. Berg)) was initially introduced as an ornamental plant, but nowadays, it is widely cultivated for the numerous beneficial properties of its edible fruits. Feijoa flowers have been included in the list of edible flowers, but despite this, they are still considered niche products due to consumer skepticism and lack of publicity.
Methods:
This study evaluated the physicochemical traits, antioxidant system, and ascorbate-glutathione cycle in feijoa flowers at five flowering stages based on the Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie (BBCH) scale.
Results:
The results showed that the optimal stage to harvest feijoa flower is the F2 stage characterized by high bioactive compounds content. Furthermore, the enzymes involved in oxidative stress and the ascorbate-glutathione cycle showed different trends during the flowering stages.
Conclusions:
This study provides new evidence to understand the possible role of bioactive compounds and ascorbate-glutathione cycle in the regulation of flower development, defining the optimal stage to harvest flowers.
... In areas where the species naturally occurs, pollen germination has been observed, by several studies, to always be greater than 69% (Franzon et al., 2005;Santos et al., 2007), although a wide variation of pollen germination was observed in the review conducted by Ramírez and Kallarackal (2017). In the present study, the low pollen germination (Table 1) may be evidence that the climatic conditions of the regions (Pato Branco and Dois Vizinhos) are not adequate for the studied genotypes. ...
... However, in Dois Vizinhos, there was a significant reduction in the effective fruit set rate for open pollination (5.8%) when compared with Pato Branco (27.5%). The combining of the analyses from both experiments performed in Dois Vizinhos and in Pato Branco revealed that, in addition to the pollen viability issue, there may have been a lack of pollinators l, particularly birds (Ducroquet & Hichel, 1997;Mattos, 1986;Ramírez & Kallarackal, 2017;Thorp & Bieleski, 2002) and bumblebees. This corroborates with the hypothesis that a lack of pollinators can result in low production and varies according to the locations, therefore complementary manual pollination is necessary (Patterson, 1990). ...
Studies of feijoa adaptability in different locations, with specific weather conditions can be useful for the cultivation of the species. The objective of this work was to study aspects of reproductive biology (pollen viability and fruit set under different methods of pollination) and flowering phenology of feijoa in regions of marginal species occurrence. Progenies of five different crosses were evaluated in 2011 in Pato Branco and Dois Vizinhos, Paraná, Brazil. Effective fruit set was low with manual self-pollination and open pollination, but was higher with manual cross-pollination, demonstrating a lack of pollinators or even self-incompatibility in some progenies. For both sites, pollen viability was extremely low and atypical for the species. The flowering period of feijoa started earlier and was extended in these marginal regions. Manual pollination is required for a good fruit set.
... For example, 'Kent' mango (Mangifera indica L.) trees require an optimum temperature of 30 °C for effective pollen germination (Dag et al. 2000). Pollination is highly sensitive to temperature extremes across all species, having a negative impact on production (Hatfield and Prueger 2015;Ramírez and Kallarackal 2017). Either high or low temperatures are known to affect the pollination physiology of trees. ...
... Moreover, higher than normal temperature (33 °C day/28 °C night) conditions during flowering have been known to cause floral abscission and ovule damage in avocado (Sedgley 1977;Argaman 1983;Davenport 1986). In vitro feijoa (Acca sellowiana) pollen germination was lower at 30 °C (Franzon et al. 2005;Ramírez and Kallarackal 2017). Pollen germination was halted at 45 °C in sugar apple (Rodrigues et al. 2016). ...
In the following section, we provide a detailed description of the flower and its parts because it is relevant to the study of pollination (see Fig. 2.1 for floral parts). Flowers are structures, which consist of an array of parts (organs) borne on a central axis called the receptacle (Rudall 2007). The whole floral structure is suspended by the peduncle, a stalk that attaches the flower to the plant (Glimn-Lacy and Kaufman 2006). The flower might be supported by leaf-like structures called bracts, which are absent or present depending on plant species (Rudall 2007). The typical flower is composed of the internal sexual parts, namely organs, which are covered by sepals and petals (Abrol 2012). The floral perianth or the outer structure of the flower is composed of the sepals referred to as the first whorl or calyx and the petals, which comprises the second whorl or corolla (Rudall 2007). Sepals have a protective function during floral development, are green but can also attain color in some plant species (Glimn-Lacy and Kaufman 2006). Petals are colored parts that function as pollinator attractants via color, shape and pattern (Abrol 2012). The male component of the flower is called the stamen which bears the filament and anther. Anthers commonly bear two pollen sacs at the upper end (Glimn-Lacy and Kaufman 2006). Within the anthers, pollen is produced through the process of microsporogenesis. Among woody angiosperms, pollen is generated through meiosis and further maturation occurs in the anthers (Ramírez and Davenport 2010). Once pollen becomes mature the anthers dehisce or split open releasing pollen grains (Abrol 2012). The female part of the flower is called the carpel or pistil and is composed of the upper end, stigma, mid part, style and lower part ovary (Fig. 1.3). Pollen contacts the stigmatic surface during pollination, and then germinates through the style reaching the ovary, which contains the ovules (Glimn-Lacy and Kaufman 2006). The ovule contains the megaspores; one of these develops into an embryo sac containing an egg (Glimn-Lacy and Kaufman 2006).
... Instead of using other scales, we modified the flowering scale to show the principal floral events since floral initiation (Table 1, Fig. 2A-O), proposing a successive set of events that are easily observed in A. sellowiana trees. Fruit development in A. sellowiana is a key event for horticultural production (Ramírez and Kallarackal, 2017). According to Thorp (2008), in the subtropics, fruits from any individual cultivar generally become mature and harvestable over a 4-6 week period. ...
... In the tropics, Quintero (2012) reported that A. sellowiana trees produce fruits throughout the year. Similarly in tropical environments, flowering occurs as a continuous process within A. sellowiana trees and produces fruit set twice yearly (Ramírez and Kallarackal, 2017). Moreover, within tropical conditions at La Mana, Yerbabuena, near Bogotá, Colombia, A. sellowiana trees have been known to produce fruits throughout the year (Ramírez Pers. ...
Acca sellowiana is an important crop and ornamental tree worldwide. The current investigation examines the
phenological growth stages of A. sellowiana according to the BBCH (Biologische Bundesantalt, Bundessortenamt
und Chemische Industrie) scale. We identified six principal growth stages in A. sellowiana, which depict (1) bud
development, (2) leaf development, (3) shoot development, (4) flower emergence, (5) flowering and (6) fruit
development. Leaf development since bud initiation to mature leaf stage occurs between three to four months.
Floral button to full flowering occurs in about eight day period. Anthesis occurs between three to four days since
the time of the floral button forms a ball of petals. Two fruit production events occurred yearly and fruits reach
maturity by four to five months. The BBCH scale has important applications in the ornamental and crop production
industries. The scale can be used in management, production and pest control practices. Environmental
factors such as precipitation play an important role in phenological changes. This investigation is sought to
expand the current knowledge on the phenology of A. sellowiana which is of interest to the general public,
horticulturists, students and researchers.
... acerola, Malphigia emarginata [56]), nutritious petals (e.g. feijoa, Feijoa sellowiana [57]) and brood sites (e.g. oil palm, Elaeis spp. [58]). ...
Bee and non-bee insect pollinators play an integral role in the quantity and quality of production for many food crops, yet there is growing evidence that nutritional challenges to pollinators in agricultural landscapes are an important factor in the reduction of pollinator populations worldwide. Schemes to enhance crop pollinator health have historically focused on floral resource plantings aimed at increasing pollinator abundance and diversity by providing more foraging opportunities for bees. These efforts have demonstrated that improvements in bee diversity and abundance are achievable; however, goals of increasing crop pollination outcomes via these interventions are not consistently met. To support pollinator health and crop pollination outcomes in tandem, habitat enhancements must be tailored to meet the life-history needs of specific crop pollinators, including non-bees. This will require greater understanding of the nutritional demands of these taxa together with the supply of floral and non-floral food resources and how these interact in cropping environments. Understanding the mechanisms underlying crop pollination and pollinator health in unison across a range of taxa is clearly a win–win for industry and conservation, yet achievement of these goals will require new knowledge and novel, targeted methods.
This article is part of the theme issue ‘Natural processes influencing pollinator health: from chemistry to landscapes’.
... The third review by Fischer and Parra-Coronado (2020) basically deals with the ecophysiology of feijoa where the authors described how climate change affects abiotic factors such as water availability, temperature, sunlight, and wind and how these environmental factors affect fruit yield and quality. For instance, pollination as a process to facilitate fruit production depends on wind yet little is understood as stated by Ramírez and Kallarackal (2017) in their review. Similarly high growing temperatures above 32 • C are reported to affect pollination and fruit set, while fruit grown in temperate regions require about 100 h of chilling below 7 • C to increase flowering (Sharpe et al., 1993). ...
Feijoa is an important minor fruit grown in New Zealand, Georgia, Colombia, United States, Italy, Portugal and Brazil. Commercial production and export is reported majorly in New Zealand and its major markets include USA, Asia, Australia and Europe, however main challenge is its short storage life that limits its economic value, thereby needing innovative efforts to extend storage life. Postharvest technologists have applied techniques such as low temperature, controlled atmosphere, ethylene, 1- Methylcyclopropene (1-MCP), CaCl2 dips, hot water dipping, step down temperature conditioning and intermittent warming with minimal success. Non-destructive methods such as near infrared have been discussed as alternative approaches to assist in segregating fruit at harvest into more homogenous batches with differing storage potential. This review highlights technologies that merit further testing for extending storage life, and promising technologies for at-harvest fruit segregation. The techniques need to fit readily into industrial practice after harvest. Technologies that support early harvesting of fruit, non-destructive analysis to segregate fruit into maturity classes at grading speed and optimal storage for differing markets, hold significant potential to expand the export industry of feijoa.
... In general, feijoa is a crop that has not been extensively investigated in scientific research. 18 This fruit is considered to be a great source of bioactive compounds, 19,20 and many studies demonstrate antimicrobial, 21 antioxidant, 20,22 anticancer 23 and anti-inflammatory activity. 24 Research aims to advance knowledge about this species, with regard to genetic improvement, because few feijoa are planted on a commercial scale. ...
BACKGROUND
Feijoa [Acca sellowiana (Berg) Burret] is a Brazilian native fruit with few commercial‐level plantations and high agroindustrial potential. A genotype evaluation experiment was conducted since 1996, aiming to obtain fruits based on the agronomical parameters, however, the selection based on chemical composition had not been evaluated to develop a new cultivar. Based on the aforementioned, this study aimed to discriminate seven accessions of feijoa by its nutritional composition, phenolic compounds, and antioxidant activity using multivariate analysis (principal component analysis and multivariate contrast), aiming the potential production of a new cultivar with better nutritional value and high antioxidant capacity.
RESULTS
Feijoa husk presented high content of ashes, lipids, proteins, carbohydrates, phenolic compounds, and antioxidant activity, comparing to feijoa pulp. However, just feijoa pulp was selected to multivariate analysis, because it is the fruit edible part. Data variability was explained in 78% and the feijoa pulp accessions were discriminated in four groups related to its characteristics. The accession 5 discrimination can be explained by the high content of ashes, carbohydrates, soluble solids, phenolic compounds, and antioxidant activity. Accession 6 was also discriminated by the high content of total acidity, pH and proteins; and low content of soluble solids.
CONCLUSION
Feijoa accessions may be indicated to increase the plant selection through hybridization with the other accessions, to produce new cultivars with better nutritional composition and antioxidant capacity. For instance, accession 5 is the most suited fruit to human consumption and is a potential plant to become a new cultivar.
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... Feijoa (Acca sellowina) is a plant from Myrtaceae family, native from Southern Brazil, Paraguay, Argentina and Uruguay [1]. Feijoa fruits have oval shape, green color even when ripe, and vary in their aspect between smooth and rough skin [2]. ...
The aim of this work was to evaluate the bioactive compounds contents and the antioxidant activity preserved in the obtained powders of dehydrated feijoa pulp after two drying methods applied: Spray drying and Freeze-drying methods. Ascorbic acid, total phenolic and total flavonoids content, antioxidant activity (by DPPH, ABTS and FRAP methods) were determined and the obtained data were evaluated using ANOVA and Tukey test (p < 0.05). Spray drying method produced powders with higher amounts of total phenolic and total flavonoid contents, while Freeze-drying method presented higher amounts of ascorbic acid and higher antioxidant activity. Both applied methods were effective in maintaining the antioxidant properties of Feijoa fruits. DOI: http://dx.doi.org/10.17807/orbital.v11i6.1223
... Climate change conditions have caused trees to modify their phenology and pollinator activity as a result of increased temperature or precipitation (Ramírez and Kallarackal, 2015;Ramírez and Davenport, 2016;Ramírez and Kallarackal, 2017;Ramírez and Kallarackal, 2018a,b). Unusual rain coupled by hail have impacted orchard tree tomato trees in La Mana, Cundinamarca, Colombia during November of 2017. ...
Tree tomato is an important crop from South America. Trees attain heights of two to four meters. The inflorescence is known as a scorpioid cyme that bears between 10–50 flowers. Tree tomato is a subtropical perennial tree that flowers between 1000 to 3000 m in the tropics and subtropics. In the tropics, flowering and fruiting occur throughout the year. Pollen size is 20 μm in polar diameter and 19 μm in equatorial diameter. Pollination is mediated by biotic vectors, such as insects e.g. bees and bumblebees. Also, abiotic vectors such as wind play an important role in pollination. Fruit growth has a characteristic sigmoidal type of growth curve. Tree tomato has a high cultivar diversity. It has important health improving properties. Fruit set per inflorescence is low. Breeding and hybridization programs have been important for obtaining pathogen and disease resistant cultivars.
This study aimed to investigate the chemical composition of essential oils isolated from Acca sellowiana (feijoa) leaves and stems and elaborate on their relevance as natural anti‐aging, coupled with molecular‐docking studies. The isolated oils were analysed using gas chromatography‐mass spectrometry analysis and investigated for inhibitory effects against acetylcholinesterase, β ‐secretase, collagenase, elastase and tyrosinase. Molecular‐modelling study was performed using MOE‐Dock program to evaluate binding interactions of major components with the above‐mentioned targets. The leaf oil revealed the predominance of caryophyllene oxide (24.3%), linalool (7.9%), and spathulenol (6.6%), while the stem oil was presented by caryophyllene oxide (38.1%), α‐zingiberene (10.1%) and humulene oxide II (6.0%). The stem oil expressed superior inhibitory activities against acetylcholinesterase (IC 50 =0.15±0.01µg/mL), β ‐secretase (IC 50 =3.99±0.23µg/mL), collagenase (IC 50 =408.10±20.80 µg/mL), elastase (IC 50 =0.17±0.01 μg/mL) and tyrosinase (IC 50 =8.45 ± 0.40µg/mL). The valuable binding interactions and docking scores were observed for caryophyllene oxide and α‐zingiberene with acetylcholinesterase. Besides, α‐zingibirene followed by linalool and τ‐cadinol revealed tight fitting with collagenase and elastase. Additionally, linalool, spathulenol and τ‐cadinol showed the best binding energy to tyrosinase. This study provides valuable scientific data on A. sellowiana as potential candidates for the development of natural antiaging formulations.
Feijoa is often found in central and north Florida landscapes as a durable and cold-hardy plant for hedges and foundation plantings, and as a dooryard fruit. Its value as a potentially heavy producer of flavorful fruits (and flavorful flowers) is frequently overlooked due to issues in pollination and limited genetic improvement. This new 5-page publication of the UF/IFAS Horticultural Sciences Department describes the opportunity and limitations of feijoa as a horticultural crop.https://edis.ifas.ufl.edu/hs1424
The Millennium Ecosystem Assessment described 4 classes of services or functions that ecosystems and their component parts deliver to the benefit of humans: provisioning, regulating, supporting, and cultural services. Birds, including Neotropical birds, provide a diverse array of services in all 4 classes. We review the literature describing ecosystem services provided by Neotropical birds, draw inference from studies of avian services in other regions when Neotropical studies are limited, and identify key information gaps. Neotropical birds provide provisioning services in the form of meat and eggs for food, and feathers for down and ornamentation. Regulating services are among the most valuable services provided by Neotropical birds, including pollination, pest control, seed dispersal, and scavenging. Neotropical birds also provide supporting services in the form of nutrient cycling, such as through the deposition of guano on offshore islands. Finally, Neotropical birds provide cultural services as pets (caged birds), sources of recreation (e.g., birdwatching, hunting), as well as by inspiring art, photography, and religious customs. Much remains to be learned about the ecology and natural history of many Neotropical birds before we can fully assign value—monetary, nonmaterial, or otherwise—to the services they provide. However, what we have learned to date makes it clear that humans benefit from birds through multiple services, including but not limited to pest reduction, pollination of some agricultural plants, and seed dispersal.
Magenta Lilly Pilly tree (Syzygium paniculatum Gaertn) has been introduced and extensively planted throughout the city of Bogotá, Colombia. This species is considered threatened or vulnerable in Australia. This paper describes seven principal BBCH stages, namely, bud development, leaf development, shoot development, flower emergence, flowering, fruit development and maturity of fruit and seed. Trees produced flowers, fruits, vegetative flushes and resting buds in about 20% of the canopy throughout the year. About 40% to 50% of the canopy showed two mass flowering and fruiting events yearly. Magenta trees provided important ecosystem services such as pollination, perching sites, and food for birds. Magenta offers a constant supply of nectar and pollen for bees from the urban forest. Honeybees were the only insects observed visiting the fully open flowers (BBCH 67). The constant production of fruits and two mass annual fruiting events are important ecosystem service. The Great Thrush (Turdus fuscater), a native bird, fed on the ripe fruit (BBCH 89). The BBCH scale is key to study ecological associations and also the benefits the trees deliver to the urban forest.
The research aimed to evaluate the polyphenolic composition and the antioxidant capacity of edible extracts of feijoa (Acca sellowiana (O. Berg) Burret) flowers. Phenolic compounds of whole feijoa flower (FM), feijoa petals (PM) and feijoa petals juice (PJ) were identified by high-performance liquid chromatography coupled with electrospray mass spectrometry and quantified by liquid chromatography coupled with ultraviolet/visible detection. Moreover, the total polyphenol (TP) content was measured spectrophotometrically and the antioxidant capacities of the extracts were evaluated by FRAP, CUPRAC, DPPH·, and ABTS·+ assays. The FM showed TP content (395.14 ± 7.91 mg GAE/L) higher than PM and PJ, and exhibited better antioxidant capacities. FM extracts were characterized by the high content of anthocyanins (115.3 ± 3.6 mg/L), flavonols (42.9 ± 3.3 mg/L) and the presence of ellagic acid (7.9 ± 0.2 mg/L) and other galloyltannins. In addition, cyanidin-3-O-glucoside and apigenin were detected in all the three extracts. The present study provided an overview on particular bioactive compounds that characterise different parts of edible feijoa flowers. Among the latter, FM proved to be the most suitable for exploitation in the food and health manufactory.
Graphic abstract:
Thousands of plant species worldwide are dependent on birds for pollination. While the ecology and evolution of interactions between specialist nectarivorous birds and the plants they pollinate is relatively well understood, very little is known on pollination by generalist birds. The flower characters of this pollination syndrome are clearly defined but the geographical distribution patterns, habitat preferences and ecological factors driving the evolution of generalist‐bird‐pollinated plant species have never been analysed. Herein I provide an overview, compare the distribution of character states for plants growing on continents with those occurring on oceanic islands and discuss the environmental factors driving the evolution of both groups. The ecological niches of generalist‐bird‐pollinated plant species differ: on continents these plants mainly occur in habitats with pronounced climatic seasonality whereas on islands generalist‐bird‐pollinated plant species mainly occur in evergreen forests. Further, on continents generalist‐bird‐pollinated plant species are mostly shrubs and other large woody species producing numerous flowers with a self‐incompatible reproductive system, while on islands they are mostly small shrubs producing fewer flowers and are self‐compatible. This difference in character states indicates that diverging ecological factors are likely to have driven the evolution of these groups: on continents, plants that evolved generalist bird pollination escape from pollinator groups that tend to maintain self‐pollination by installing feeding territories in single flowering trees or shrubs, such as social bees or specialist nectarivorous birds. This pattern is more pronounced in the New compared to the Old World. By contrast, on islands, plants evolved generalist bird pollination as an adaptation to birds as a reliable pollinator group, a pattern previously known from plants pollinated by specialist nectarivorous birds in tropical mountain ranges. Additionally, I discuss the evolutionary origins of bird pollination systems in comparison to systems involving specialist nectarivorous birds and reconstruct the bird pollination system of Hawaii, which may represent an intermediate between a specialist and generalist bird pollination system. I also discuss the interesting case of Australia, where it is difficult to distinguish between specialist and generalist bird pollination systems.
Climate change has altered the rainfall patterns worldwide. In the last century, the amount of annual precipitation and occurrence of extreme precipitation events have increased worldwide (Rosenzweig et al. 1996). Under climate change conditions, unseasonal rains often occur during dry periods, or as extended rainy seasons causing flooding events. Magrin et al. (2014) reported an increase in climate change driven extreme events i.e. flooding, droughts, heavy rains, landslides, heat waves in Central and South America (Fig. 3.1). The rainfall pattern drives climate regulation within a biome (Scarano and Ceotto 2015). It is also a key to controlling watershed levels and soil stability on mountain slopes (Scarano and Ceotto 2015).
Climate change has been known to impact plant pollination by changing flowering phenology and by distressing the activity of pollinators, e.g. flight (Abrol 2012). Similarly, phenological decoupling of plant–pollinator interactions (Settele et al. 2016) have been reported. Specifically, plants and insects have different responses to changing temperature, creating temporal (phenological) and spatial (distributional) disparities that cause problems at the population level (Reddy et al. 2013). Mismatches could impact plants by impairing decreased insect visitation that means less pollen deposition, whereas pollinators could face reduced food availability (Reddy et al. 2013). However, in some circumstances, pollinator–plant synchrony does not cause mismatches, due to generalist pollinator species keeping pace with changes in forage-plant flowering by switching between host plants (Fig. 5.1) (Settele et al. 2016). Animal biology and ecology associated with pollination i.e. population, reproductive aspects, and activity - flight, etc., are essential for understanding the impacts manifested by climate change. Relatively very little research has been conducted on the physiology of many crucial pollinators influenced by warming temperatures (Scaven and Rafferty 2013). This is evident in many tropical regions worldwide, where, animal pollinators comprise much more species and interactions, when compared to temperate conditions (Figs. 1.2 and 5.2).
Tree-pollinator interactions are important ecosystem services that are threatened by global warming and climate change. Very few investigations have focused on fruit-tree pollination interactions in the tropics. In this paper, we analyze knowledge gaps proposed by the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) with special reference to the tropics and associated with (1) the effects of climate change on plant-pollinator interactions and (2) pollinator diversity and population attributes within the context of nature conservation.
Feijoa is mostly an allogamous fruit tree of the Myrtaceae family, so its productivity relies on suitable pollen carriers for cross pollination. Preliminary trials carried out at Videira Experimental Station, S.C., with bird-cage screen, allowing free access to bees but not to birds, showed a low bee efficiency as pollinators. Similar results were obtained in New Zealand where pollination of Feijoa is attributed to two bird species. In Santa Catarina, petals of every Feijoa flower were eaten by the fauna before natural dropping at senescence. Observations made during the blooming period in several years, showed that the majority of the bird species from the Traupidae and Turdidae families known as fruit-eaters in Santa Catarina highlands, also eat the fleshy and sweet as well as showy petals of feijoa. The most frequent species identified were: Traupis s. sayaca, Traupis b. bonariensis, Stephanophorus diadematus, Elaenia mesoleuca, Turdus r. rufiventris, Turdus spp., Tangara spp. and Mimus saturninus jrater: Specimens of the three first species were caught by netting, so it was possible to observe that they were carrying feijoa pollen on their head top.
Acca sellowiana (Myrtaceae) and Casearia lasiophylla (Flacourtiaceae) are reported for the first time for the Argentinean flora. The genus Acca has not been previously recorded for Argentina. These species are widely known in other countries because of their multiple uses. Distinctive characters of both species are provided together with illustrations (photographs) and information about their geographical distribution, vernacular names, uses and ecological observations.
Macadamia nuts are a valuable culinary resource, but yields can vary substantially between varieties, orchards and seasons. The nuts are harvested from commercial varieties derived from two endemic Australian tree species; Macadamia integrifolia Maiden & Betche and Macadamia tetraphylla L.A.S. Johnson. While some aspects of crop management for this relatively new crop are well known and generally well applied-including variety selection, irrigation and pesticide application-progress towards increasing quantity and reliability of yield has proven elusive. Hand pollination studies indicate that inadequate cross pollination contributes to low nut set and thus low yield. Typically just 0.3% of flowers develop into harvestable nuts. Lack of nut development after flowering and early abscission are indicators of poor fertilisation of the ovule. Honey bees ( Apis mellifera Linnaeus, 1758) are routinely reported as the most common insect visitor to macadamia flowers, and are widely regarded as the most important agent for transferring pollen between flowers. Stingless bees, beetles, flies and birds also visit flowers and have been considered as pollinators. In this review, we aim to collate what is currently known about the pollination of macadamia varieties, assess the factors that may hinder effective pollination and subsequent yield, and identify opportunities to improve both pollination and yield in commercial macadamia orchards.
The reproductive behavior of Japanese plum has not been studied as in other Prunus species. Thus, a number of cultivars are particularly prone to erratic fruit set showing low yield for reasons that are not clear. Traditionally, the factors related to pollination have not been considered as causes of low yield in this crop, but in the last years lack of fruit set was recorded in different cultivars due to reproductive failure. Japanese plum, like other Prunus fruit tree species, is self-incompatible and requires cross pollination to ensure fruit set because this genus is unable to bear fruit parthenocarpically. Therefore, knowledge of pollination requirements of cultivars is essential to solve problems of low yield related to lack of pollination and for new orchard plantation plan with adequate proportion of pollinizers. The incompatibility relationships between Japanese plum cultivars have not been studied comprehensively until the last decade. An important amount of information has been revealed in this period, since a high number of commercial cultivars are currently available and new cultivars are being obtained from different breeding programs. In this article, the information available on the reproductive process in Japanese plum is reviewed, paying special attention to pollination factors and incompatibility relationships between cultivars. The S-RNase genotype of 222 cultivars compiled herein, allocated in 26 Incompatibility Groups, five of them described for the first time, will be valuable for fruit growers to choose adequate pollinators in commercial orchards, and for breeders to choose parental genotypes and select offsprings in breeding programs.
The research deals with the biological specifics of the development of the male gametophyte in Feijoa sellowiana Berg. 1% agar-agar solution and solutions of sucrose of three different concentrations (20%, 30%, 40%) were used for the investigation. We germinated pollen gains in the Moist Chamber van Tieghem (hanging drop); to paint the pollen grains, the acetocarmine method was applied. Based on the results of the research the low fertility of the Feijoa pollen grains has been defined. 12 hours after having the seeds sowed in all cases only 1-2% of the pollen grains were germinated, whereas 34-47% was germinated after 24 hour period. In this case 40% sucrose solution appeared to be optimal. In case of sucrose solution of 20 and 30% the amount of the germinated pollen grains mounted 13-24% within 24 hours after being sowed. The shape and size of the pollen grains change less in accordance with being depended on the forms of Feijoa. In 98% cases the pollen grains have a triangular form. We also come across with roundish, elliptic and oval pollen grain forms. Their sizes range between 221- 262 mcm2
The objective of this work was to establish a suitable culture medium and conditions to be used for in vitro germination tests of feijoa pollen. It also had the aim to test the possibility of storage of this pollen in a freezer (-18 °C). The pollen was collected from flowers immediately after anthesis. The test media were the standard (10% sugar, plus 1% agar dissolved in distilled water), and the addition of two H 3 BO 3 (0.65 mM and 1.3 mM) to this medium. Incubation temperatures of 25 and 30 ºC were tested. High average percentage of in vitro germination (79.7%) was obtained after three hours of incubation at 25 °C. Highest germination percentages (85.6, 52.3 and 9.3% after storage for zero, 90 and 150 days respectively) were achieved with the addition of 1.3 mM of H 3 BO 3 to the standard medium. Feijoa pollen lost viability after 90 and 150 days in freezer storage, reducing germination percentage from 79.7 to 45.9% and 6.1% respectively.
Acca sellowiana (Myrtaceae) é uma frutífera nativa da região Sul do Brasil e nordeste do Uruguai, que vem despertando grande interesse devido ao alto potencial organoléptico de seus frutos. Neste trabalho, teve-se como objetivo a caracterização do tipo de sistema de incompatibilidade atuante em A. sellowiana, através da avaliação do desenvolvimento dos tubos polínicos. Utilizaram-se dois acessos: 458, sendo autocompatível, e 101, auto-incompatível. A maior porcentagem de germinação de grãos de pólen foi observada no acesso 101, com 68,8% de grãos de pólen germinados. Não foram observadas diferenças no crescimento dos tubos polínicos em pistilos autopolinizados ou de polinização cruzada, em ambos os acessos. O crescimento completo do tubo polínico até o ovário ocorreu em pistilos coletados 96 horas após a polinização, independentemente do tratamento aplicado. Sugere-se a ocorrência de auto-esterilidade ou auto-incompatibilidade tardia ou pós-zigótica, considerando que o abortamento dos frutos de A. sellowiana é uniforme e ocorre num prazo curto, por volta de 20 a 30 dias após a fertilização das flores.
Pollen morphology of 44 genera and 101 species from the Myrtaceae tribes Kanieae, Myrteae and Tristanieae was surveyed using scanning electron microscopy (SEM) and light microscopy (LM). Most Myrteae pollen were brevicolpate and granulate, which is unique within Myrtaceae, and these are most likely ancestral characters for this tribe. Two main pollen types were observed in tribe Kanieae, one form being with syncolpate colpi and a distinctive granulate exine, and the other with parasyncolpate colpi and a less ornamented exine. Genera Tristania and Thaleropia of tribe Tristanieae produce the smallest pollen in Myrtaceae, whereas Octamyrtus of tribe Myrteae produces the largest pollen observed in Myrtaceae.
Acca sellowiana Berg. (Myrtaceae) is a fruit-bearing treelet or shrub native from the highlands of South Brazil. The plant is currently in the domestication process. Its fruit is sweet-acidified and can be consumed raw or be used for the preparation of juice and jam. Thus, information on the development, morphology and anatomy of the fruit is of great interest, and was featured as the objective of this study. The average fruit dimensions (ovary surrounded by the hypanthium) in the bloom stage were 0.6 cm in length and 0.4 cm in diameter, being ten times smaller than the ripe fruit. Longitudinally, three distinct regions were observed: a locular-, a sublocular- and a prolongation region. In a transverse cross-section in the middle of the fruit, three regions were delimited: 1) epidermis (peel) with simple unicellular trichomes. 2) parenchymatous region (flesh) rich in stone cells, isolated or aggregated in small groups of 2-3 cells; with eight radially distributed concentric periphloematic vascular bundles; and with many spherical glands near the epidermis. 3) inner region (pulp) with small cubic cells, organized in 3-4 layers around the locules, various containing druses. The four locules are separated by septa. The numerous ovules originate from axillary placentas, with two rows per locule. No nectaries were observed. As the fruit develops, groups of thin-walled cells appear in the intermediate region. These cells become very large and transform into stone cells. The placentas grow and occupy the whole space within the growing locules, as these locules grow bigger and seeds develop. Thus, the ripee fruit has a peripheral region of firm consistence and astringent taste, and a soft sweet core.
Due to its export potential, nutraceutical characteristics and agro-industrial use, the pineapple guava is considered a promising crop in Colombia. Different postharvest studies have indicated that the fruit has a typical climacteric behavior with high respiration rates and ethylene production, requiring immediate postharvest refrigeration to preserve its quality (temperatures of 4-10°C, 90-95% relative humidity). As the postharvest period elapses, fruit weight loss and pH increase; and fruit firmness decreases. The results are contradictory for the tendency of soluble solids and titratable acidity, probably influenced by varietal characteristics, plant age and climatic and growing conditions.
Actualmente no existen estudios de la viabilidad y caracterización del grano de polen de feijoa ante lo cual la cantidad y calidad del polen producidos por una flor, son aspectos importantes en estudios evolutivos y de adaptación de genotipos. Así, se determinó la solución germinativa adecuada para realizar pruebas de germinación in vitro, mediante pruebas de las siguientes soluciones: agua, agar, agua + sacarosa 5%, agua + sacarosa 10%, agar + sacarosa 5% y agar + sacarosa 10%, ante lo cual, en la solución germinativa compuesta por agar y sacarosa al 5% se registró el mayor porcentaje de germinación de granos de polen en el tiempo. Se efectuó la prueba de fertilidad del polen para los dos clones por medio del método de tinción con azul de lactofenol en tres estados de apertura floral E1 (pétalos visibles), E2 (sépalos desplegados) y E3 (pétalos maduros), presentando 100% de tinción del total de granos observados por estado de apertura floral. Se realizaron pruebas de germinación para los dos clones en los tres estados de apertura floral y se observó en el clon 8-4 a las 10 horas después de la siembra para el estado E3, alcanzando un alto porcentaje de germinación (80%), mientras que los otros dos estados no germinaron en el tiempo de medición establecido. En el clon 41, la germinación inició a las 10 horas después de la siembra para el estado E2 y a las 12 horas para el E3, mientras que el E1 no germinó. Los estados E2 y E3 alcanzaron 80% aproximado 16 horas después de siembra.
Maduración y comportamiento poscosecha de la feijoa (Acca sellowiana (O. Berg) Burret). Una revisión Ripening and postharvest behavior in the pineapple guava (Acca sellowiana (O. Berg) Burret). A review RESUMEN La feijoa es considerada un cultivo promisorio en Colombia, por su potencial de exportación, características nutracéuticas y uso agroindustrial. Los diferentes estudios poscosecha indican que los frutos de feijoa presen-tan comportamiento típico climatérico, con elevadas tasas respiratorias y de producción de etileno, requirien-do refrigeración poscosecha inmediata para preservar su calidad (temperatura de 4 a 10ºC; humedad relativa de 90-95%). A medida que transcurre el periodo poscosecha, aumentan la pérdida de peso y el pH, y disminuye la firmeza del fruto. Los resultados son contradictorios en cuanto a la tendencia de los sólidos solubles y de la acidez titulable, influenciados probablemente por las características varietales, edad de la planta y por las condiciones climáticas y de cultivo a que hayan estado expuestos.
Bird pollination in the Neotropical region is by far known as an important interaction to ecosystem function, but perching birds visiting flowers are still very often observed as merely opportunist visitors. Although these other birds do not rely only on floral resources, there are many plant species that do depend solely on them for pollination. These flowers display some features, including morphology and different kinds of resources, quite different from the ornithophilous flowers pollinated by hummingbirds. We review the syndrome of ornithophily in the Neotropical region and tear it apart into the two exploitation methods to determine the floral features that might favor pollination by hovering birds or by perching birds. We listed the Neotropical perching bird species mentioned in the literature as pollinators to take a look at that avian richness. We expect that as more studies on forest canopies are taken in the Neotropics, more interactions between perching birds and flowers may be observed and reveal its real role in the biology of both groups.
Acca sellowiana has anatropous, bitegmic and crassinucellate ovules. The outer and inner integuments are double-layered except in the micropyle, where they are composed of more layers; the micropyle is zig-zag shaped. The egg apparatus lies at the micropylar pole, and the zynergids present a conspicuous filiform apparatus. The antipodal cells are present in the chalazal region, persisting before the occurrence of double fertilization. The zygote is visible 21 days after pollination; nuclear endosperm is already present. The first mitotic division of the zygote occurs at 24th day. The globular, cordiform and torpedo embryo stages can be seen at 30, 45 and 60 days after pollination, respectively. The mature embryo characterized by the presence of a well-developed hypocotyl-radicular axis with two fleshy and folded cotyledons was observed 120 days after pollination. Endosperm is absent in the seeds, and the embryo has spiral form, characteristic of Myrtinae. The zygotic embryology studies of A. sellowiana indicate that this species has embryological characteristics which are in agreement with those reported for Myrtaceae (Myrteae, Myrtinae), and also broaden the knowledge about the sexual reproduction of this native species, whose commercial cultivation has been growing.
A goiaba-serrana (Acca sellowiana, Myrtaceae) é uma das poucas espécies vegetais cujas pétalas são habitualmente usadas como alimento por aves nos Neotrópicos. Registramos aqui o consumo de pétalas desta mirtácea por nove espécies de aves Passeriformes, numa arvoreta isolada em área urbana de Gramado, Rio Grande do Sul. A maior freqüência de visitas foi registrada para espécies de Thraupidae, aves predominantemente frugívoras. As aves tomavam as pétalas entre as mandíbulas e arrancavam ou cortavam porções, deixando sinais característicos nas flores. Thraupis sayaca e Tangara preciosa foram registrados recolhendo porções de pétalas e levando-as entre as mandíbulas, a primeira espécie tendo sido duas vezes observada fornecendo pétalas a ninhegos. Devido ao seu porte médio e à beleza das suas flores, bem como à atração de diversas espécies de pássaros mesmo em área urbanizada, reiteramos aqui o uso de A. sellowiana em arborização urbana no Sul e Sudeste do Brasil.
Na presente parte do nosso Catálogo Palinológico analisamos a morfologia dos grãos de polén de 140 espécies de Mirtáceas ocorrentes no Estado de Santa Catarina. O estudo dos grãos de polén destas Mirtáceas permitiu agrupar as espécies estudadas em grupos polínicos, segundo as propriedades das aberturas e da estrutura das exinas. Não foi possível separar nem as espécies nem os gêneros em bases da respectiva morfologia polínica. Desta maneira os grupos polínicos são heterogêneos tanto quanto aos gêneros compreendidos, quanto à ocorrência ecológica das espécies.
Se citan por primera vez para la flora argentina las especies Acca sellowiana (Myrtaceae) y Casearia
lasiophylla (Flacourtiaceae), las cuales se destacan en otros países por sus múltiples usos. El
género Acca no había sido citado anteriormente para Argentina. Se detallan los caracteres distintivos
de las especies, se las ilustra mediante fotografías y se brinda información acerca de su distribución,
nombres vernáculos, usos y observaciones ecológicas.
Feijoa suffers from high rates of flower and fruit abortion, and widely varying fruit characteristics, which are directly related to pollination problems. However, efficient pollination mostly depends on pollen vigour. Thus, methods to improve pollen vigour have become an important focus for both breeders and growers. An orthogonal design method (L9[3]4) was used to compare the effectiveness of key factors (e.g. concentrations of sucrose, H3BO3, CaCl2 and GA3) to determine pollen vigour, and to optimise the culture medium for in vitro pollen germination. The four factors that influenced pollen germination in order of significance are as follows: GA3 > CaCl2 > H3BO3 > sucrose. These variables influenced pollen tube growth in the following order: CaCl2 > H3BO3 > sucrose > GA3. The optimal culture medium for promoting pollen vigour was 10% sucrose, 1.95 × 10–3 mol/L H3BO3, 4 × 10–4 mol/L CaCl2 and 80 mg/L GA3.
Flowering and pollination are key reproductive events leading to mango fruit development. The mango inflorescence is a branched terminal panicle or determinate thyrse. Mango flowers are either male (staminate) or hermaphroditic, containing both stamens and carpels (perfect). Sex ratio (the proportion of perfect to staminate flowers) is a variable component within panicles, trees and among cultivars. Endogenous, genetically regulated events and environmental factors influence sex ratio. Pollen grains are 20-45 μm long. Mango pollination commences with deposition of pollen on the stigmatic surface of the style. Pollen germination is different among cultivars. Mango pollen viability is highest soon after anther dehiscence and rapidly degrades. Mango viability is an important feature for breeding programs. Floral anthesis occurs in the morning or at night depending on cultivar. Mango has self- cross- pollination, self-incompatibility and self-sterility systems; however, some cultivars are semi- compatible or fully compatible. Wind is important in mango pollination. Outcrossing rates using molecular markers have been poorly studied around the world, and more studies need to be conducted in this particular field of research. In vitro mango pollen germination has been used widely. This review provides the current state of knowledge of pollination from a diverse array of environments and climatic conditions ranging from subtropical to tropical environments were mango is grown.
The book covers interplay between pest management strategies and safety of pollinators. Detailed information is provided on pests and pollinators of temperate, subtropical and tropical fruit crops. Most of the fruit crops are highly cross pollinated and depend upon insects or benefit from insect pollination for fruit set. Insect pests on the other hand cause major economic damage on fruit crops in tropics, subtropics and temperate. Evidently, pest management in fruit crops on one hand and providing safety to the pollinators on the other is a challenging task in the context of increasing horticultural productivity without upsetting the ecological balance. This book aims to integrate and develop pest control strategies in a way to minimize their impact on beneficial insect species such as natural enemies and pollinators to enhance fruit production and quality. The book covers interplay between pest management strategies and safety of pollinators. Detailed information is provided on pests and pollinators of temperate, subtropical and tropical fruit crops. Pollinators play a crucial role in flowering plant reproduction and in the production of most fruits and vegetables. Most of the fruit crops are highly cross pollinated and depend upon insects or benefit from insect pollination for fruit set. Insect pests on the other hand cause major economic damage on fruit crops in tropics, subtropics and temperate. Evidently, pest management in fruit crops on one hand and providing safety to the pollinators on the other is a challenging task in the context of increasing horticultural productivity without upsetting the ecological balance. This book aims to integrate and develop pest control strategies in a way to minimize their impact on beneficial insect species such as natural enemies and pollinators to enhance fruit production and quality. Most of the fruit crops are highly cross pollinated and depend upon insects or benefit from insect pollination for fruit set. Insect pests on the other hand cause major economic damage on fruit crops in tropics, subtropics and temperate. Evidently, pest management in fruit crops on one hand and providing safety to the pollinators on the other is a challenging task in the context of increasing horticultural productivity without upsetting the ecological balance. This book aims to integrate and develop pest control strategies in a way to minimize their impact on beneficial insect species such as natural enemies and pollinators to enhance fruit production and quality. The book covers interplay between pest management strategies and safety of pollinators.
Feijoa sellowiana Berg is cultivated as a non-timber forest tree in New Zealand, Colombia and France, and is well known for its high dietary value fruit. F. sellowiana was introduced into China during the 1980s. However, it is particularly prone to erratic fruit set and very little work has been conducted on its reproductive biology. F. sellowiana 'Mammoth' cultivar was subjected to a light microscopy analysis to clarify male and female gametogenesis. The results showed that the formation of anther wall conforms to the basic type. The tapetum is of the glandular type. Cytokinesis in microsporocyte meiosis is of simultaneous type, and the micropore tetrads are tetrahedral. Mature pollen grains are two-celled with three germ pores. The ovules are anatropous, bitegminous, and tenuinucellate. The megaspore tetrads are arranged linearly, and the megaspore at the chalazal end is functional. The functional megaspore undergoes three successive mitoses resulting in the formation of an 8-nucleate embryo sac of the Polygonum type. Our results elucidate the mechanism that regulates sexual reproduction in F. sellowiana, thus expanding the prospects for F. sellowiana breeding programs and further molecular and genetic analyses of this species.
This book has a wider approach not strictly focused on crop production compared to other books that are strictly oriented towards bees, but has a generalist approach to pollination biology. It also highlights relationships between introduced and wild pollinators and consequences of such introductions on communities of wild pollinating insects. The chapters on biochemical basis of plant-pollination interaction, pollination energetics, climate change and pollinators and pollinators as bioindicators of ecosystem functioning provide a base for future insights into pollination biology. The role of honeybees and wild bees on crop pollination, value of bee pollination, planned honeybee pollination, non-bee pollinators, safety of pollinators, pollination in cages, pollination for hybrid seed production, the problem of diseases, genetically modified plants and bees, the role of bees in improving food security and livelihoods, capacity building and awareness for pollinators are also discussed.
Pineapple guava or feijoa are common names of Feijoa sellowiana Berg a member of the Myrtaceae family and the only species of the genus Feijoa. The scientific name is a compliment to both J. Feijó, Director of the Natural History Museum of S. Sebastian, in Brazil, at the time of its discovery, and F. Sellow, the naturalist who collected the specimen later classified by Berg (Hooker 1898). The plant is an evergreen bushy shrub or small fruit tree (Fig. 1A), which may occasionally reach the height of 5–7 m. The leaves are smooth, dark green on the upper surface and whitish tomentose on the underside. The flowers (Fig. 1B) are especially notable for their petals, red on the inside and whitish on the outside, and by the numerous dark red stamens. The fruits (Fig. 1), yellow-green when ripe, emit an agreeable scent due to the production of several volatile compounds (Hardy and Michael 1970; Shaw et al. 1989), and contain numerous small (2–2.5 mm), kidney-shaped seeds.
Feijoa is a climacteric fruit that needs to remain on the tree up to the point of natural fruit drop to attain its typical texture and strong aroma. Identifying horticultural maturity is difficult and mixed maturities at harvest can cause significant problems in later storage because of heterogeneity. Feijoas can be stored for up to four weeks at 4°C depending on the cultivar, with the end of storage life predominantly determined by flavour loss and internal browning. External changes during storage are limited except for shrivelling due to water loss, a slight change in flesh colour and appearance of symptoms resulting from bruising during harvesting and postharvest handling. The main storage disorders reported are chilling injury and CO2 damage.
Pollination is a key event for fruit set. Worldwide, there has been an increasing interest in apple pollination. Apple pollen grains are elliptical and tricolpate. Pollen germination is highly dependent on temperature. Most apple pollination occurs through cross-pollination; however, some cultivars have been reported to self-pollinate. Most apple cultivars have a gametophytic self incompatibility (GSI) system; however, others are semi compatible, or fully self compatible. The most common insect pollinator of apple is the honey bee. Other effective pollinator species include Hymenopterans, Dipterans and Coleopterans. Wind seems not to be an effective mechanism for pollination. Environmental conditions such as temperature, rain and high wind speed negatively affect pollination. This article reviews recent developments in our knowledge of apple pollination focusing on recently developed cultivars growing in the tropics.
Pollination of lychee (Litchi chinensis Sonn. ) by the honeybee was studied in Israel's two commercial cultivars, 'Mauritius' and 'Floridian'. Pollination rate, which was determined in a mixed 'Mauritius' and 'Floridian' plot, followed a consistent pattern: it was low at the first male (M1) 'Mauritius' bloom and reached a high value only when the pseudohermaphroditic (M2) 'Mauritius' bloom started. Pollen density on bees collected from 'Mauritius' inflorescences was very low during the M1 bloom and increased to very high values during the M2 bloom. These results indicate that the 'Mauritius' M1 bloom does not play an important role as a source of pollen for pollination. Pronounced, significant, and consistent differences in nectar volume per flower and sugar concentration in the nectar were found between M1. M,. and female (F) 'Mauritius' flowers. Values were very high in F flowers, medium in M2 flowers, and low in M1 flowers. Accordingly, the density of bees found on inflorescences was high during the F bloom, intermediate during the M2 bloom, and low during the M1 bloom. The positive correlation between bee density and sugar concentration in the nectar was highly significant for M2 and F 'Mauritius' flowers. The nectar contained three sugars: glucose (43%), fructose (39%), and sucrose (18%). This ratio was the same in nectar from M1, M2, and F 'Mauritius' flowers.
Anthers of Feijoa sellowiana Berg. (feijoa) produced pollen callus when cultured in Murashige and Skoog medium containing 2,4-dichlorophenoxyacetic acid and benzyladenine or in nurse cultures. Somatic callus was also formed in large amounts from the connective and from the cut end of the filament. Anthers containing microspores at the stage immediately prior to the first pollen mitosis cultured in the presence of 3% sucrose, presented the highest frequencies of induction. Androgenetic divisions were initiated by the formation of two morphologically equal cells, the so-called B-pathway. Attempts to regenerate pollen plants were unsuccessful but leaf-like structures could be obtained in regeneration media containing combinations of gibberellic acid and benzyladenine.
Pollination and seed dispersal of Brazilian Myrtaceae). Myrtaceae is one of the most important plant families in Brazilian vegetation, especially forests. Its white, hermaphrodite flowers, with numerous stamens, and the fleshy fruits are exploited by a variety of animal species. This revision aimed to summarize the knowledge of the reproductive ecology of Brazilian Myrtaceae, bringing together information about the pollinators and seed dispersers of a great number of species. Data were compiled from the literature, complemented with unpublished information from the authors and other researchers. The majority of the pollination studies were carried out in Cerrado vegetation, whereas seed dispersal studies were conducted mainly on Atlantic Forest. Pollen is the major resource offered by Myrtaceae flowers. The flowers are visited mainly by bees, the pollinators of almost all species studied until now. The greatest number of visits to flowers is from Meliponinae and Bombinae bees (Apidae). Other insects such as flies and wasps also visit myrtaceous flowers, occasionally acting as pollinators. Bird pollination was reported for Acca sellowiana (O. Berg) Burret and Myrrhinium atropurpureum Schott, in which the main floral resource are the fleshy and sweet petals. Birds and monkeys are the main seed dispersers of Brazilian Myrtaceae, although other mammals, reptiles, fish and ants may interact and casually disperse seeds. Information on the pollination and seed dispersal agents of Myrtaceae in Brazil are still scarce, and its knowledge is essential to species preservation and the conservation of the Brazilian forests.
Feijoa sellowiana (Myrtaceae) was studied under cultivation in New Zealand, California, and Japan, to determine which floral visitors are the most effective pollinators. A large range of insects and birds visited feijoa flowers to collect pollen or feed on the sugary petals. Estimation of pollen deposited on stigmas showed that only large birds deposited sufficient compatible pollen to initiate fruit development. An exclusion experiment confirmed this. Observations of the behaviour and size of the floral visitors explained why insects and smaller birds are ineffective pollen vectors. In orchards with high densities of large birds, flowers were visited at earlier stages but, even at lower densities, visits were sufficient to ensure pollination. In orchards that lacked birds, fruit set was minimal. Bird visitation was greater at the edges of blocks and, in large blocks, fruit set was significantly lower in the centre of the block. Studies of animal movements indicated that large birds such as blackbirds (Turdus merula) and mynas (Acridotheres tristis) were the most efficient cross pollinators. Specific recommendations to growers are that large birds should be encouraged, honey bees should not be put in feijoa blocks, varieties should be interplanted within the row and blocks should be small (
Floral organogeny and development are described for three species of South American Myrtoideae: Acca sellowiana, Luma apiculata, and Ugni molinae. The flowers have large numbers of stamens which vary in size but are all initiated on the flank of the invaginated apex. The floral architecture is the result of the degree of synchrony of the timing of stamen initiation and hypanthial expansion. In A. sellowiana and U. molinae, stamen initiation is synchronised with hypanthial expansion, resulting in the even distribution of stamens over the entire hypanthial surface. Stamens of L. apiculata are initiated during and after hypanthial expansion, resulting in a discontinuous ring of stamens at the periphery of the hypanthium. Development in these species is in contrast to New Zealand Myrtoideae, where stamen initiation is complete prior to the completion of hypanthial expansion, resulting in the inner‐most stamens forming a discontinuous ring.
The role of pollination in seed production and fruit development of the feijoa (Acca sellowiana (Berg) Burret) was examined in the partially self-fertile cultivar Apollo. Growth and quality attributes of fruit from cross-, self-, and open-pollinated flowers were markedly different. Cross-pollination gave the highest fruit set, fruit weight, and pulp (endocarp) development. More seeds were present in fruit from cross-pollination than in those resulting from selfing. Seed distribution within the fruit was not affected by pollination treatments. Correlations between seed number and fruit weight, and seed number and internal fruit quality (pulp development), were found in the feijoa cultivars Apollo, Triumph, Mammoth, and Gemini. In ‘Apollo’, a correlation between seed number and fruit shape was also found. It is concluded that pollination of feijoa can have significant effects on fruit uniformity via its effect on seed production.
Avocado (Persea americana Mill.) flowers, with their synchronously dichogamous behaviour, are considered to be pollinated by honeybees, despite the lack of any direct evidence. Results in southern Florida showed that avocado pollen was transferable by wind, and was dispersed over a brief period of time (15 - 60 min) each day. Ten 'Hass' avocado orchards in the Santa Clara River Valley, CA, USA, planted far from any known 'Zutano' polliniser trees, were selected to investigate the impact of honeybees on pollen transfer. 'Zutano' pollen (5 g per insert) was placed at the entry to beehives (approx. eight beehives per orchard) and refreshed four-to-five times during the flowering season. Successful pollinations were determined by parental analysis of harvested 'Hass' fruit from trees located at various distances from the beehives, and at three different stages of fruit development, using microsatellite DNA markers. The results showed no significant difference in the proportions of 'Zutano'-pollinated fruit with respect to distance and/or development stage between orchards provided with beehives containing 'Zutano' pollen and those without supplemented pollen. This strongly suggests that honeybees are not the major pollinators of avocado, and that most avocado flowers are self-pollinated by wind.
Introduction Shoot Development Phenology of Flowering Regulation of Shoot Growth and Flowering Flowering Hypotheses Conclusion Literature Cited
(1) On the Canary Islands and Madeira typical bird-flowers occur in at least twelve species of six genera, although true flower-birds are absent. This inconsistency is in part elucidated by field observations on exotic and wild plants of Tenerife. —(2) In the Botanical Garden of Orotava it could be observed that various ornithophilous plants, which were introduced there, were visited by indigenous birds for nectar and in one case (Orthostemon) for food tissue. Of the three bird species involved, an endemic race of Chiffchaff (Phylloscopus collybita) and resident Blackcaps (Sylvia atricapilla) exploit, and pollinate, flowers legitimously, while the Wild Canary (Serinus canaria) is predominantly a destructive nectar robber. —(3) The insular Chiffchaff also proved to be a regular pollinator in the wild, at least ofCanarina canariensis andIsoplexis canariensis, two ornithophilous paleoendemics. Ornithophily, thus, is naturally practised on the island, though by birds basically insectivorous. —(4) A list of Macaronesian plants bearing the more or less complete ornithophilous syndrome is presented, including newly recognizedTeucrium heterophyllum andScrophularia calliantha. —(5) On biogeographical and faunistic grounds it is presumed that the modern visitors of Canarian bird flowers are secondary rather than the original partners of the continental tertiary flora in which these plants originated. Palearctic immigrants, when becoming resident on the islands during and since the Pleistocene, adopted facultative nectar feeding, entering an orphaned food niche. Casual flower visits in Europe suggest a certain predisposition of the Chiffchaff and the Blackcap for the exploitation of flowers. — (6) The ability of unspecialized birds to acquire nectardrinking spontaneously and to pass this habit on to their offspring, is demonstrated by a population of Tree Sparrows (Passer montanus) which have visited ornithophilousKniphofia (Liliaceae) in Berlin for several years.
Acca sellowiana (Berg) Burret is a predominantly allogamous species with hermaphrodite flowers that has barriers to self-fertilisation such as dichogamy by protogyny and self-incompatibility. This study aimed to identify when self-incompatibility occurs in A. sellowiana flowers submitted to self-pollinations. Pollinations were made using nine known self-incompatible accessions in several treatments including manual cross-pollination, manual self-pollination, no pollination and natural pollination. Flowers were pollinated and pistils collected at times ranging from 1 to 30 days after pollination (DAP). In both cross- and self-pollinations the fertilisation occurred from 18 DAP and the zygote was visualised at 24 and 26 DAP, respectively. The abscission of the self-pollinated flowers increased from 26 DAP onwards, when significant differences (P < 0.05) were found for the percentage of abscission among self-pollinated and cross-pollinated flowers. At 30 DAP, 72% of self-pollinated flowers were abscised
Thesis (Ph. D.--Botany)--University of Auckland.
Asiatic Honeybee Apis Cerana: Biodiversity Conservation and Agricultural Production
- D P Abrol
Abrol, D.P., 2013. Asiatic Honeybee Apis Cerana: Biodiversity Conservation and
Agricultural Production. Springer, New York.
- B Azam
- F Lafitte
- F Orby
- J L Paulet
Azam, B., Lafitte, F., Orby, F., Paulet, J.L., 1981. Le feijoa en Nouvelle-Zélande. Fruits 36,
361-384.