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Evaluation of genetic stability using FRAPD markers as novel method along with antioxidant and anti-diabetic properties of micropropagated Salacia chinensis L.
Abstract
Salacia chinensis L., a perennial medicinal plant, is well-known for its well-documented anti-diabetic properties. The daily growing demand in pharmaceutical industry is stimulating the conservation and wide-ranging production of the plant using plant tissue culture techniques (micropropagation). In the present study, the plants generated by direct micropropagation from nodal explants were assessed using fluorescently labeled RAPD (FRAPD) primers. Although standard RAPD primer bands in agarose gel showed genetic stability, using FRAPD analysis in genetic DNA sequencer as a novel strategy showed more accurate and reliable method has indicated by the evidence in 5% genetic variation. Antioxidant and anti-diabetic activities of micropropagated plants versus mother plant were examined using DPPH, FRAP, α-amylase, and α-glucosidase assays. The results showed that the micropropagated plants, which are able to produce higher amount of secondary metabolites than the mother plant, possess higher in vitro antioxidant and anti-diabetic properties.
... However, in previous report (Chavan et al. 2015a), we have effectively developed an in vitro propagation system along with elevated accumulation of mangiferin during various regeneration stages of S. chinensis. More recently, Bagnazari et al. (2018) assessed the antioxidant and antidiabetic potential of aerial parts of in vitro regenerated plantlets of S. chinensis. Till date, no report has been published on elicitor-treated increase in biomass, industrially important biomolecules with in vitro pharmacological properties in callus cultures of genus Salacia. ...
... Recently, few researchers have assessed the impact of plant growth regulators on antioxidant capability of callus and aerial parts of micropropagated Salacia spp. (Chavan et al. 2015a;Bagnazari et al. 2018;Mahendra et al. 2020); however, the present study is the first and sole report describing elicitormediated increase in antioxidant potential of callus cultures of S. chinensis. ...
The present investigation aimed to improve callus biomass, polyphenolic content, biosynthesis of mangiferin and biological potential following application of different elicitor treatments for medicinally important Salacia chinensis L. The leaf-derived callus cultures were established on Murashige and Skoog’s (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D: 2.0 mg/l) and 6-benzylaminopurine (BAP: 1.5 mg/l). These cultures were treated with different elicitors viz. jasmonic acid (JA), methyl jasmonate (MeJA) and yeast extracts (YE). The highest calli biomass (five-fold increase within 4 weeks) was achieved when callus was treated with JA (75 µM). The callus obtained on MS medium supplemented with 2,4-D (2.0 mg/l), BAP (1.5 mg/l) and treated with JA (75 µM) displayed augmented values for total phenolics, flavonoids and mangiferin contents. Besides, same treatment elicits the calli for antioxidant properties as evaluated by 2,2-diphenyl-2-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP) and metal chelating assays. This is the first report on the elicitation study in genus Salacia and, therefore, the discoveries suggested that, S. chinensis calli might be a perfect source for large-scale production of industrially important secondary metabolites. Concurrently data provide accumulated information demonstrating its prominent antioxidant effect revealing its potential without disturbing natural resources.
... radical scavenging activity compared to the mother plant. The lower free radical scavenging activity of mother plant extract might be due to the presence of lower amount of phenols and flavonoids (Bagnazari et al. 2018). Similar results were also obtained in Nardostachys jatamansi (Bose et al. 2016), Rumex nepalensis (Bhattacharyya et al. 2017) and Atropa acuminata (Rajput and Agrawal 2020), where micropropagated plants possessed strong radical scavenging activity compared to the mother plant. ...
Rumex hastatus D. Don, a traditional medicinal plant is known for its antitumorous, antiangiogenic and antibacterial potential. HPLC analysis of different plant parts showed that root had the maximum quantity of luteolin and rutin and thus was selected for the establishment of aseptic cultures. Murashige and Skoog’s medium supplemented with 5 µM TDZ proved best for developing greenish-brown and compact calli in 98% root cultures within 30 days. Upon subculturing such callus pieces differentiated an average of 10.50 ± 1.29 shoots per culture. The excised shoots were transferred on MS + 0.1 µM IBA medium where they developed an average of 12.03 ± 2.49 roots per shoot. These plantlets were successfully acclimatized under greenhouse conditions and their genetic fidelity was evaluated employing SRAP and SCoT markers which revealed their high similarity with mother plant proving their true-to-type nature. Interestingly, the in vitro regenerants showed elevated levels of phenols, flavonoids, luteolin and rutin contents and higher antioxidant activities over the mother plant as revealed by phosphomolybdenum and DPPH assays. For elicitation, 100 mg/L phenylalanine was best for enhancing luteolin content (407.18 ± 10.58 μg/g d.w.) up to 17.42-fold over control (22.10 ± 0.57 μg/g d.w.) whereas, 25 mg/L chitosan proved most effective for accumulation of rutin content (1169.07 ± 46.49 μg/g d.w.) up to 2.74-fold over control (312.41 ± 12.42 μg/g d.w.). To the best of our knowledge, this is the first report on micropropagation and elicitation of luteolin and rutin in R. hastatus through root culture.
... SCoT marker is based on the short conserved regions surrounding the start region (ATG start codon) and is directly related to the functional genes (Collard and Mackill 2009). Similar to our findings, the occurrence of genetic variations between mother plant and regenerants were reported in D. thyrsiflorum (6.52%) using SCoT and ISSR markers (Bhattacharyya et al. 2015), P. zeylanica (3%) using ISSR and SCoT markers (Sharma and Agrawal 2018) and in Salacia chiensis L. (5%) using fluorescently labeled random amplified polymorphic DNA (FRAPD) markers (Bagnazari et al. 2018). ...
Atropa acuminata Royle ex Lindl. (family Solanaceae) is a critically endangered therapeutic herb, known for its immense therapeutic potential against innumerable ailments. In view of protecting this species from brink of extinction, present work focuses upon development of an effectual micropropagation protocol via indirect organogenesis using root-derived callus. Best callusing was observed on Murashige and Skoog (MS) medium augmented with 10 µM Thidiazuron (TDZ), where 99% of root explants induced whitish-green and compact calluses within 45 days. Upon sub-culturing on same medium (10 µM TDZ), these callus pieces differentiated an average of 5.54 ± 0.65 shoots having 2.38 ± 0.37 cm of length in 71.5% of the explants, after 28 days. MS + 1 µM indole-3-butyric acid (IBA) resulted in optimum rooting response where an average of 8.08 ± 0.19 roots having an average length of 7.28 ± 0.11 cm were produced. Micropropagated plants with well-developed and thick roots were acclimatized under greenhouse conditions. Genetic fidelity of ex vitro acclimatized plants using start codon targeted (SCoT) and sequence-related amplified polymorphism (SRAP) markers, revealed 96% similarity between mother plant and micropropagated plants. These plants showed higher yield of phenols, flavonoids and exhibited better antioxidant (DPPH and phosphomolybdenum assay) activities in comparison with mother plant. Higher levels of photosynthetic pigments and antioxidant enzymes were also observed in these plants as compared to the mother plant. Besides, quantification of atropine and scopolamine using high-performance liquid chromatography (HPLC) in different plant parts of acclimatized plantlets revealed higher amount of both the alkaloids in leaves. The present protocol shall be gainfully employed for large-scale micropropagation, conservation and extraction of biotherapeutic molecules for commercial purposes.
Studies related with the storage of peach fruits have received great relevance in Egypt. In this study, the effect of pre-harvest sprays of calcium chloride and chitosan, separately and in combination, on quality attributes and storability of peach fruits stored at 0±1 °C was studied. ‘Early Swelling’ peach trees were sprayed twice with 1% or 2% calcium chloride. The first spraying was at pea stage, while the second one was performed at 10 days before harvesting. Chitosan sprays were performed at 0.5 or 1%, alone or in combination with 1 and 2% calcium chloride, at 10 days before harvesting. Untreated trees served as control. Fruits were harvested at maturity stage, then packaged and stored at 0±1 °C and 85-90% of relative humidity. Fruit physical and chemical properties were evaluated at 7-day intervals. Results showed that pre-harvest application with 2% CaCl2+1% chitosan was most effective in minimizing weight loss (%) and decay (%), as well as in maintaining maximum firmness and lengthening shelf life. Fruit color was not affected by any of the treatments, while untreated fruits and calcium chloride treatment alone, at both applied concentrations, maintained higher total soluble solids (TSS, %), total phenolic content, and lower titratable acidity percentage.
Simarouba glauca DC. is a multipurpose tree species known for oil, timber, and medicinal properties. The application of biotechnological methods for genetic improvement of this species depends on the availability of an efficient plant regeneration system. In this study, the shoot regeneration potential of various seedling-derived explants was assessed after culturing on Murashige and Skoog (MS) and woody plant (WP) medium containing different growth regulators. The explants differed in their capacity for shoot bud formation and subsequent shoot elongation on the media tested. Shoot bud induction was achieved at a high frequency (44.8–76.2%) from different explants on MS medium with 2 mg L⁻¹ 6-benzylaminopurine (BAP) as compared to other media tested. Cotyledons exhibited the highest capacity for shoot bud induction (76.2%) and shoot elongation (9.1 elongated shoots per explant). The in vitro-regenerated shoots rooted at a frequency of 66.7% after pulse treatment in 10 mg mL⁻¹ indole-3-butyric acid (IBA) solution for 5 min followed by culture on half-strength WP medium with 0.2 mg L⁻¹ IBA. The regenerated plants were acclimatized and established in the glasshouse with a survival rate of 80%. Molecular characterization of regenerated plants using 14 random amplified polymorphic DNA (RAPD) and 15 intersimple sequence repeat (ISSR) primers revealed a high number of monomorphic bands, with only 1.6–2.6% of the bands being polymorphic. The regeneration system established in the study has the potential to be used for rapid multiplication, conservation, and genetic transformation of this species.
Background
Diabetes has caused a major burden to the health sector in the developing countries and has shown an increasing trend among the urban population. It is estimated that most patients are with type II diabetes which could be easily treated with dietary changes, exercise, and medication. Sri Lanka carries a long history ayurvedic medicine where it uses the plant for treating many diseases. Therefore it is important to screen medicinal plants scientifically so they could be used safely and effectively in the traditional medical system and also be used for further investigations.Adenanthera pavonina is a plant used in the Ayurvedic medical system in Sri Lanka for treating many diseases including diabetics. We evaluated the anti-diabetic properties and the antioxidant properties of Adenanthera pavonina leaves. Methods
The methanol extract of the leaves was sequentially extracted with petroleum ether and thereafter was partitioned between EtOAc, and water. The α-amylase inhibition assay was performed using the 3,5- dinitrosalicylic acid method. The antioxidant activities were measured using the DPPH free radical scavenging activity and the total phenolic content using Folin-Ciocalteu’s reagent. The cytotoxicity of the extract was evaluated using the Brine shrimp bioassay. ResultsThe IC50 values of α amylase inhibitory activity of MeOH, EtOAc, petroleum ether, and water were 16.16 ± 2.23, 59.93 ± 0.25, 145.49 ± 4.86 and 214.85 ± 9.72 μg/ml respectively and was similar to that of Acarbose (18.63 ± 1.21 (μg/ml). Antioxidant activities were also determined and the EtOAc fraction showed the highest total phenolic content (34. 62 ± 1.14 mg/g extract) and the highest DPPH scavenging activity with an IC50 of 249.92 ± 3.35 μg/ml. Conclusion
The leaf extracts of Adenanthera pavonina exhibit remarkable α-amylase inhibitory activity in the crude methanolic extract. Hence leaves of Adenanthera pavonina has a potential to be used as a regular green vegetable and also be investigated further in isolating pure compounds with anti-diabetic activity.
Oxidative stress related diseases often arise from over production of free radicals and reactive oxygen/nitrogen species. The prevention of these diseases could be possible with the use of natural antioxidant plants that could be promising as therapeutic candidates. Since antioxidant properties of a species could be stem from phenolic compounds, it is, therefore, important to evaluate antioxidant and total/individual phenolic and flavonoid content. For this purpose, we evaluated antioxidant properties of ginger (Zingiber officinale Rosc.) based on three parameters: the antioxidant capacity, total phenolic and flavonoid content as well as identification of phenolic acids of water extract (WEG) and ethanol extract (EEG) of ginger. For antioxidant capacity, we performed FRAP, CUPRAC assay, Fe2+ chelating ability, DPPH and DMPD radical scavenging activities. Also, total phenolic and flavonoid contents in both extracts were also measured via Folin Ciocalteu’s method. For identification of phenolic acids, HPLC-MS/MS method was performed. The results showed that EEG had generally better antioxidant activity than WEG in all assays. HPLC-MS/MS analysis showed that there are at least eight different phenolic acids found in ginger, among which pyrogallol p-hydroxybenzoic acid, ferulic acid and p-coumaric acid were more abundant in both extracts. This study clearly showed that ginger extracts demonstrated effective antioxidant properties and their consumption may reduce or delay the progression of diseases that oxidative stress take place due to lack of antioxidant supplementation.
Cornus alba L. (white dogwood) is an important ornamental shrub having a wide range of applications such as reforestation programs and soil retention systems. The vegetative propagation of dogwood by cuttings may be slow, difficult, and cultivar dependent; therefore, an improved micropropagation method was developed. Nodal stem segments of C. alba cultivars ‘Aurea’ and ‘Elegantissima’ were cultured on media enriched with six different sources of macronutrients. Media were supplemented with either N⁶-benzyladenine (BA) or thidiazuron (TDZ) in combination with 1-naphthaleneacetic acid (NAA). Regardless of the cultivar, the best shoot proliferation was observed on Lloyd and McCown medium (woody plant medium (WPM)) at pH 6.2, containing 1.0 mg L⁻¹ BA, 0.1 mg L⁻¹ NAA, and 20–30 g L⁻¹ sucrose. Rooting of regenerated shoots was achieved by an in vitro method when different concentrations of NAA or indole-3-butyric acid (IBA) were tested. Microcuttings were rooted for 8 wk on medium enriched with 0.25 mg L⁻¹ NAA and potted into P9 containers in the greenhouse. The final survival rate of the plants after 20 wk was 80% for ‘Aurea’ and 90% for ‘Elegantissima’. Genetic stability of the micropropagated plants was confirmed by using two DNA-based molecular marker techniques. A total of 30 random amplified polymorphic DNA (RAPD) and 20 inter-simple sequence repeat (ISSR) primers resulted in 197–199 and 184–187 distinct and reproducible band classes, respectively, in ‘Aurea’ and ‘Elegantissima’ plantlets. All of the RAPD and ISSR profiles were monomorphic and comparable with the mother plant.
Background/Objectives: Salacia chinensis L., a high valuable anti-diabetic medicinal plant of Hippocrateaceae family, possess various medicinal properties. Its anti-inflammatory, hepatoprotective and anticancer activities originated from huge number of isolated phytochemicals such as mangiferin and salacinol. Excessive and indiscriminate collection for supplement of global demands has caused classified this plant as endangered species. Establishment of an effective regeneration system for S. chinensis via direct organogenesis as a most reliable method was the main goal of this study. Methods: The explants include leaf, node and shoot tips were inoculated on Murashige and Skoog (MS) medium fortified with different concentrations and combinations of Plant Growth Regulators (PGRs) including 6-Benzylaminopurine (BAP), Kinetin (Kin), 1-Naphthalene Acetic Acid (NAA) and Indole-3-Acetic Acid (IAA) for direct regeneration by shoot formation. Findings: The most efficient shoot regeneration in terms of the proliferation percentage (87.81 ± 3.22%), number (5.37 ± 0.02) and length of shoots (3.22 ± 0.04 cm) was obtained on MS basal medium supplemented by BAP (1.0 mg/l) and NAA (0.5 mg/l). The highest frequency in vitro root formation (91.33 ± 2.02%) with maximum number of 4.35 ± 0.03 roots with a length of 2.47 ± 0.03 cm was successfully achieved in half strength MS medium supplemented with 2.0 mg/l IBA. Application: The established system has this potential to be successfully employed in order to conservation and masspropagation of S. chinensis for commercial utilization.
To study ripening-related chilling injury (CI) of bell pepper (Capsicum annuum L.), fruit at mature green, breaker, and red-ripe stages were stored at 1, 5, 7, and 10°C for 4 weeks. Surface pitting was evaluated after storage at 1°C for 2 weeks followed by a 2-day exposure to room temperature (20°C). Exposing fruit to 1°C enhanced water loss, respiration, ethylene production, and electrolyte leakage, but slowed color change. Weight loss, respiration, ethylene production, electrolyte leakage, and color change increased more in breaker than in mature green and red-ripe fruit. No pitting symptom was observed at temperatures of 5 to 10°C. After storing peppers at 1°C for 2 weeks, breaker stage fruit exhibited chilling symptoms of severe surface pitting with more sheet pitting and deeper peel depression. Mature green fruit showed only moderate pitting. However, red-ripe peppers showed no injury and cells showed a normal appearance after low-temperature storage (1°C). These results show that bell peppers tended to be more susceptible to chilling temperature while at the breaker stage and that the increase in visible CI is correlated with increased water loss, respiration, ethylene production, electrolyte leakage, and color change during storage.
Exacum bicolor, an endemic and endangered medicinal plant, belongs to the family Gentianaceae. A rapid
protocol has been developed for efficient multiple shoot induction by testing nodal explants on Murashige and Skoog
(MS) medium supplemented with various cytokinins. The cytokinins 6-benzyladenine (BA), 6-furfurylaminopurine (Kn),
2-isopentenyladenine (2-iP) and zeatin (Zn) were used individually and in combination at different concentrations (0.5,
1.0, 2.0, 5.0, and 10.0μM). The maximum number of shoots
(19.33±1.09 per explant) as well as their fresh weight (5.1±
0.68 g) and dry weight (216.83±2.84 mg) were obtained with
10.0μM BA+2.0μM Kn. After 4 wk, the multiple shoots
from agar culture were subcultured into liquid medium containing the same growth regulator combinations. After 8 wk of
liquid culture, the best treatment had about tenfold increase in
shoot number (199.5±1.14 per explant). The fresh weight
(13.76±0.14 g) and dry weight (909.33±1.92 mg) were
highest with full strength MS medium supplemented with
3% sucrose and containing 10.0μM BA+2.0μM Kn. Maximum root development was observed after 30 d with 0.5μM
indole-3-butyric acid (IBA) supplementation. Regenerated
plants were successfully transferred to pots containing coco
peat:perlite mixture and showed a 75% survival rate. Genetic
fidelity of in vitro plantlets compared to mother plant were
assessed using random amplified polymorphic DNA
(RAPD) and inter-simple sequence repeats (ISSR) markers.
All the regenerated plants were genetically identical to their
mother plant, showing no detectable genetic variation in the
regenerated plantlets. Thus, this protocol could be successfully used for mass multiplication and germplasm conservation
ofE. bicolor.
This chapter presents the results of cytogenetic and molecular genetic studies on tissue and organ cultures
from some Gentiana species. Cytogenetic analysis of calli from seven gentians showed that all of them (except for G.
punctata
) consisted mainly of the cells with diploid
and/or near-diploid chromosome sets
with low anaphase aberration. Species specificity of cytogenetic structure
was established for cell populations in vitro. An increase in the proportion of polyploid cells was found for G.
acaulis
callus after long-term culture. RAPD analysis of tissue cultures from six gentians showed that culture resulted in genetic changes, with the species differing in the level of genetic variation. RAPD and ISSR analyses of G.
pneumonanthe
and G.
lutea
genetic variation
in tissue and organ cultures
and regenerated plants revealed the most significant changes in isolated root cultures as well as in long-term cultured tissues. At the same time, direct and indirect regenerants had the least genetic difference compared to donor plant
. The restriction maps of nuclear 18S-25S ribosomal DNA from G.
acaulis
, G.
punctata
, G. lutea, and G.
asclepiadea
were constructed based on the results of blot hybridization. The decrease of 18S-25S rDNA
amount was found in cultured tissues. In contrast to other species, G.
lutea
showed intragenome heterogeneity of rRNA genes as well as qualitative rDNA changes in tissue culture, such as the appearance of repeats with altered length. A relationship has been suggested between the peculiarities of the structural organization of the 18S-25S rRNA
gene cluster and its rearrangements. Rearrangements of 5S rDNA
were not found in cultures of Gentiana L. species, except for the variation in nucleotide methylation pattern at restriction sites.
Heating `Golden Delicious' apples (Malus domestica Borkh.) for 4 days at 38C or pressure-infiltrating them with a 4% CaCl 2 solution reduced decay and maintained fruit firmness during 6 months of storage at 0C. Heating reduced decay caused by Penicillium expansum Link ex Thorn by ≈30%, while pressure infiltration with CaCl 2 reduced decay by >60%. Pressure infiltration with CaCl 2 after heating reduced decay by ≈40%. Pressure infiltration maintained firmness best (>84 N), as measured with a manually driven electronic fruit-firmness probe, followed by heat and CaCl 2 (76 N), heat alone (71 N), and no treatment (control) (60 N). Force vs. deformation (FD) curves from a puncture test with a fruit-firmness probe mounted in a universal testing machine showed that fruit heated before storage were firmer than all nonheated fruit, except those pressure-infiltrated with 4% CaCl 2 . However, FD curves also showed that apples pressure-infiltrated with 4% CaCl 2 differed quantitatively from apples in all other treatments, including those heated.
Muskmelon senescence is directly associated with a decline in hypodermal mesocarp membrane integrity and its Ca concentration, but infusing Ca into melons has been a problem. Fully ripened and abscised hybrid honeydew [Cucumis melo L. (Inodorus Group) 'Honey Brew'] and netted muskmelon [Cucumis melo L. (Reticulatus Group) 'Explorer'] fruit were submerged (dipped) 20 min at 25 ± 3 °C in a solution containing a Ca-chelate, a Mg-chelate, a combination of both chelates, or no mineral chelate. Following 10 or 24 days of cold storage (4 °C for 'Explorer' and 10 °C for 'Honey Brew'), fruit were analyzed for mineral content and various senescence-related parameters. Abscised 'Honey Brew' fruit dipped in either Ca-chelate or (Ca+Mg)-chelate and abscised 'Explorer' fruit dipped in (Ca+Mg)-chelate, followed by 10 days cold storage, had hypodermal mesocarp Ca concentrations of at least 6.0 mg · g-1 dry weight. Maintaining hypodermal mesocarp tissue Ca concentrations at this level during postharvest storage, especially for fully ripe 'Honey Brew' fruit, maintained membrane integrity and fruit firmness, and extended storage life 2.4-fold (i.e., to 24 days). The senescence regulatory effect of postharvest Ca-chelate treatments on abscised 'Explorer' was highly variable, compared to 'Honey Brew', which appeared to be due to the surface netting interfering with movement of Ca into the hypodermal mesocarp. Thus, postharvest Ca-chelate application to abscised 'Honey Brew' fruit could delay fruit senescence in commercial storage, and open up new markets for fully ripened honeydew melons.
The present investigation was carried out in the experimental field of Division of Fruit Science, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar, Srinagar during the year 2010 to 2011 with a view to study the various physical changes that occur during storage and to prolong the shelf life of plum under ambient storage conditions by preharvest application of various chemicals. Fruit size, weight and firmness recorded continuous decrease with the advancement of storage period. However, 0.5% calcium chloride (CaCl 2) proved to be more efficacious in minimizing these losses. Maximum increase in fruit size and weight at the time of harvest was recorded with the preharvest application of 60 ppm NAA. Physiological loss in weight (PLW) and spoilage followed continuously increasing trend with the advancement of storage period. Among the various preharvest treatments, 0.5% CaCl 2 applied 20 and 10 days before the expected date of harvest proved to be the most effective treatment in retaining the fruit quality during the entire storage period. Such fruits exhibited minimum loss in weight, maximum retention in firmness and minimum spoilage on each sampling date. In general, overall acceptability of fruits decreased with the passage of storage time. However, fruits treated with CaCl 2 were rated as most acceptable and it was followed by Gibberlic acid (GA 3) treatment at the end of storage period under ambient conditions.
The aim of the presented study was to determine the effect of foliar application of CaCl2 on the level of β-carotene, lutein, tocopherols and phenolic compounds in the leaves of lettuce cv. Omega (Lactuca sativa L.). The experiments were conducted in the greenhouse of the Faculty of Cultivation and Fertilisation of Horticultural Plants, University of Life Sciences in Lublin. During the growing period, 7 and 14 days before harvest, the plants were treated with a solution of CaCl2 with concentrations of 0.1 M and 0.2 M. Plants sprayed with water were the control treatment in the experiment. Analyses were performed on whole leaves and the blade without midrib. The obtained results indicate that the leaves of lettuce cv. Omega are a good source of phenolic compounds, carotenoids and tocopherols. The dominant carotenoid in lettuce cv. Omega was β-carotene. Foliar application of CaCl2 on the plants did not have any significant effect on the level of β-carotene and lutein in the whole leaves. The contents of tocopherols, total phenolic compounds and chlorogenic acid were dependent on the concentration of CaCl2. The application of 0.1 M CaCl2 solution in the plants resulted in a decrease in the level of total phenolic compounds and chlorogenic acid, and an increase in tocopherol content. However, the treatment of the plants with 0.2M CaCl2 solution caused a lowering of the concentration of tocopherols and an increase in the content of chlorogenic acid and total phenolic compounds.
The present investigation was carried out in the plain areas of Chitwan to determine the promising plant growth regulators (PGR) promoting growth and yield of chilli cultivars Jwala and Suryamukhi during winter-summer season of 2003/2004. Suryamukhi ranked superior to Jwala for most of the yield attributing characters, whereas Jwala was better in vegetative characters than Suryamukhi. Among PGRs, 2,4-D at 2 ppm was better for fruit set, number of fruits per plant, fruit length, number of seeds per fruit, seed weight per fruits, 1000 seed weight and fruit yield where as NAA at 40 ppm gave the highest leaf area index (LAI). PGRs were ineffective in promoting flowering and fruiting during winter season. GA 3 at 10 ppm exhibited maximum amount of ascorbic acid content. The treatments, 2 ppm 2,4-D, 5 ppm triacontanol, 40 ppm NAA and 10 ppm GA 3 produced 28.75%, 25.70%, 13.61% and 2.30% higher fruit yield over control, respectively. The highest net profit and B:C ratio were recorded in case of 2 ppm 2,4-D. The use of GA 3 as foliar spray was not economical.
Tomato fruits (cv. Belle) were harvested at the middle-red ripe stage and exposed at 5°C and 10°C for up to 28 days. Weight loss percentage was faster for fruits held at 10oC compared to 5°C. While the weight lost during storage at 10°C was 18.7%, fruits at 5°C over the same period showed a 9.6% loss. There were only slight changes in soluble solids and titratable acids content during the storage period studied. Although soluble solids increased slightly over the storage period, there were no significant differences between the two temperatures. The titratable acidity, expressed as citric acid, tended to be lower at 5°C, with a significant difference observed only on Day 14 of storage. Total reduction of initial vitamin C content was 3.5 mg/100 g (at the 5°C) and 2.5 mg/100 g (at the 10°C). The results showed that lower temperature did not significantly reduce vitamin C content in comparison with higher temperature, with the exception on Day 7 of storage. At both temperatures and at every stage of storage time pericarp firmness decreased as storage time increased. The decrease in firmness was delayed by the lower temperature. The colour development (value a) of skin increased with increasing storage duration at both temperatures, but there were no differences among temperatures.
The present study reports an efficient in vitro micropropagation protocol for a medicinally important tree, Terminalia bellerica Roxb. from nodal segments of a 30 years old tree. Nodal segments taken from the mature tree in March-April and cultured on half strength MS medium gave the best shoot bud proliferation response. Combinations of serial transfer technique (ST) and incorporation of antioxidants (AO) [polyvinylpyrrolidone, PVP (50 mg l(-1)) + ascorbic acid (100 mg l(-1)) + citric acid (10 mg l(-1))] in the culture medium aided to minimize browning and improve explant survival during shoot bud induction. Highest multiplication of shoots was achieved on medium supplemented with 6-benzyladenine (BA, 8.8 μM) and α-naphthalene acetic acid (NAA, 2.6 μM) in addition to antioxidants. Shoot elongation was obtained on MS medium containing BA (4.4 μM) + phloroglucinol (PG, 3.9 μM). Elongated shoots were transferred to half strength MS medium containing indole-3-butyric acid (IBA, 2.5 μM) for root development. The acclimatization of plantlets was carried out under greenhouse conditions. The genetic fidelity of the regenerated plants was checked using inter simple sequence repeats (ISSR) and randomly amplified polymorphic DNA (RAPD) analysis. Comparison of the bands among the regenerants and mother plant confirmed true-to-type clonal plants.
Pre-and post-harvest physiology and quality responses of green pepper (Capsicum annuum L. cv 'Standar p.13/0211003-01-Agris') on exogenous Gibberellic acid-GA 3 (100 μM), Prohexadione-Calcium (100 mg l -1), Cycocel (100 mg l -1) and Ethephon (100 mg l -1) applied as foliar sprays, were investigated. Among PGRs, GA 3 @ 100μM was effective in promoting flowering and better for vegetative characteristics. Chlorophyll a+b concentration of leaves was markedly inhibited by GA 3 , Prohexadione-Calcium, Cycocel and Ethephon application while, the maximum quantum yield of primary photochemistry (F v /F m) and the ratio F v /F o was slightly increased under GA 3 . The above indices were significantly depressed under Cycocel, Ethephon and Prohexadione-Calcium. CO 2 production pattern was negatively related with chlorophyll fluorescence (F v /F o) yield and ascorbic acid content. The Brix content and the "maturity index" were depressed after Prohexadione-Calcium, Cycocel and Ethephon application. In general, the best green pepper appearance was found under control and GA 3 whereas, pre-and post-harvest physiology and quality characteristics dropped sharply and green peppers were not marketable under the three growth retardants.
In order to reduce horticultural produce losses, two Brazilian tomato varieties were submitted to post-harvest handling procedures combining sorting, refrigerated storage and different carton packages. These procedures were evaluated with respect to their effects on the produce shelf life. Studies were conducted to analyze coloration, firmness, flavour and weight loss changes in mature green tomatoes stored at 7°C, 13°C and ambient temperature (24°C). In general, after 9 days of storage, higher storage temperatures promoted higher sweetness and weight loss levels, as well as lower firmness. The study also included a comparison between some tomatoes held at 24°C for 9 days and a sample kept at 13°C for 22 days, showing that the produce from these storage conditions had fairly similar postharvest characteristic results. Although sorting and package factors affect some isolated characteristics, they did not seem to strongly influence tomato shelf life.
Background:
Lampaya medicinalis Phil. (Verbenaceae) is a plant used by Aymara and Quechua ethnic groups from Northern Chile as folk medicine in the treatment and cure of various diseases. The aim of this study was to investigate the in vitro antioxidant activity, total phenols content, total flavonoids content, total antioxidant activity, reducing power, brine shrimp cytotoxicity and identify the principal chemical constituents.
Methods:
The crude hydroethanolic extract (HEE) and its partitioned fraction: hexane (HF), dichloromethane (DF), ethyl acetate (EAF), n-butanol (BF) and soluble residual aqueous fraction (RWF) were evaluated for their antioxidant activity using different assays namely, DPPH, ABTS, FRAP, β-carotene bleaching assay. The content of total phenolics and total flavonoids were measured by Folin-Ciocalteau and by the AlCl3 colorimetric method, respectively. Reducing power was determined by phosphomolybdate and hexacyanoferrate (III) methods. Biotoxicity assays were performed on shrimps of Artemia salina. The EAF was fractionated using chromatographic methods.
Results:
Considerable amount of phenolic and flavonoid contents were recorded in the hydroethanolic extract (HEE) and its derived fractions. Although HEE and all its derived fractions exhibited good antioxidant activities, the most distinguished radical scavenging potential was observed for ethyl acetate fraction (EAF). EAF showed the higher radical scavenging activity by DPPH (95%) and by ABTS (98%), antioxidant activity by FRAP (158.18 ± 5.79 mg equivalent Trolox/g fraction), β-carotene bleaching assay (86.8%), the highest total phenols content (101.26 ± 1.07 mg GAE/g fraction), the highest total flavonoids content (66.26 ± 3.31 μg quercetin/g fraction). The EAF extract showed an reducing power of 78% and 65% using the phosphomolybdate and hexacyanoferrate (III) assays, respectively.Four flavonoids, two p-hydroxyacetophenone derivatives and one iridoid were isolated from Lampaya medicinalis for the first time.
Conclusion:
EtOAc soluble fraction (EAF) shows the strongest antioxidant activity, and it can be attributed to its high content in phenolic and flavonoid compounds. It can be concluded that L.medicinalis can be used as an effective natural source of antioxidant, as ethnomedicine and as a commercial basis for the development of nutraceuticals.
In the present work, Qingzhuan tea, a unique dark tea produced by post-fermentation technology, was selected to investigate its antioxidant and pancreatic α-amylase inhibiting activities. Water extract of Qingzhuan tea was successively isolated by solvent partitioning procedures to obtain chloroform, ethyl acetate, n-butanol, sediment and residual aqua fractions. Of different fractions, the ethyl acetate fraction (QEF) had the highest total polyphenols and catechins contents, demonstrated the strongest DPPH radical scavenging activity and exhibited the greatest inhibitory effect on porcine pancreatic α-amylase activity in vitro. Further separation of QEF by a Sephadex LH-20 column generated eight subfractions (QEF1–QEF8), with QEF8 being the most active subfraction based on the assays above mentioned. The major active components in QEF8 were identified as catechins EGCG and ECG by LC-MS analysis, with contents of 22.29 % and 11.11 % respectively. Inhibitory effects of catechin standards EGCG and ECG on porcine pancreatic α-amylase activity were also observed. In conclusion, Qingzhuan tea or its water extract could be potentially used as complementary therapy ingredients for diabetes treatment through lowering postprandial blood glucose, and catechins EGCG and ECG may be the most efficient components in the water extract.
Aconitum violaceum Jacq. is an important medicinal species used for various health ailments including renal pain, rheumatism and high fever. In the present report, a reproducible in vitro regeneration system for Aconitum violaceum Jacq. has developed from the nodal segment of the plant. Induction of shoot buds was achieved on basal Murashige and Skoog (MS) medium. The shoots were elongated on MS medium supplemented with 0.5 μM 6-benzylaminopurine (BAP) and 0.1 μM α-napthaleneacetic acid (NAA) and subsequently transferred to rooting medium. In vitro grown microshoots of A. violaceum were encapsulated in the alginate beads. The success rate of their re-growth was found to be approximately 85.43 %. Of the encapsulated microshoots, 39.86 % exhibited formation of multiple shoots following re-growth on plant growth regulator free MS medium. Healthy root formation was observed in all microshoots following 2 weeks of transfer on half-strength MS medium containing 0.1 μM indole-3-acetic acid (IAA) and 1.0 μM α-naphthalene acetic acid (NAA). These plants were subsequently transferred to pots containing a mixture of soil, sand and compost (1:1:1 v/v), and same were then shifted in the greenhouse with 87 % survival rate. The molecular analysis was carried out using 35 random amplified polymorphic DNAs (RAPD) primers and 25 inter simple sequence repeats (ISSR) primers. Cluster analysis of the RAPD and ISSR profile revealed an average similarity coefficient of 0.966 and 0.974, respectively, confirming genetic stability of tissue culture-raised (TR) plants and synthetic seed-derived plants (SR). The phytochemical analysis of tissue culture-raised and synthetic seeds-derived plants showed higher aconitine content than control plant. The propagation protocol developed in this study provides a basis for germplasm conservation and harnessing the medicinally active compounds of A. violaceum.
Talinum triangulare is a medicinally important herb and various parts of the plant are used pharmaceutically for the treatment of different diseases. In our study, a rapid and efficient protocol for micropropagation has been developed from shoot tip and nodal explants of T. triangulare. High shooting frequency (93.33 %) was achieved with shoot tip explants when cultured on Murashige and Skoog’s (MS) medium supplemented with 1.0 mg/L 6-benzyl amino purine (BAP) producing an average of 12.50 ± 0.23 shoots and 5.07 ± 0.02 cm shoot length per explant. A combination of 0.5 mg/L BAP and 0.5 mg/L kinetin was found to be more effective by producing 15.67 ± 0.25 shoots and 6.22 ± 0.02 cm shoot length per explant. The microshoots were excised and cultured on half-strength MS and full-strength MS medium containing different concentrations of indole-3-acetic acid and indole-3-butyric acid (IBA) for root induction. More number of roots (45.10 ± 0.96) with an average length of 5.46 ± 0.08 cm was obtained on half-strength MS medium supplemented with 0.5 mg/L IBA. The rooted shoots were successfully transplanted from different planting substrates to the field with a 100 % survival rate. Random amplified polymorphic DNA analysis was carried out using four random decamer primers. The amplification products were monomorphic in the micropropagated plants and were similar to the mother plant. Absence of polymorphism revealed that no variation was induced, thus maintaining the genetic integrity of the micropropagated plants of T. triangulare.
The post-harvest performance of sweet pepper 'California Wonder' was tested under three different packages (open trays, non-perforated and perforated polyethylene bags) stored at temperatures of 4°C, 6.5°C and ambient (17°C) for 25 days. Data on weight loss, skin green colour retention, incidences of chilling injury and diseases were collected and subjected to statistical analysis. Fruit weight loss was significantly lowest at storage temperatures of 4°C and 6.5°C and non-perforated packaging. Skin green colour retention was significantly highest on fruits held at 4°C and 6.5°C on day 5 and at 6.5°C on days 10 to 25 compared to ambient storage. However, packaging did not significantly affect colour retention. The interaction of 6.5°C and non-perforated packaging had significantly (p<0.05) highest level of green colour retention throughout the storage period. Storage temperature did not significantly affect the incidence of diseases in sweet pepper, whereas, non-perforated packaging had significantly (p<0.05) highest incidence of disease. The interaction of storage at 4°C and non-perforated packaging had significantly (p<0.05) highest incidence of diseases. Interactions between non-perforated packaging and storage temperatures of 4°C and 6.5 °C showed significantly (p<0.05) higher incidences of diseases after exposure to ambient conditions for 2 days. Temperature was the major factor in determining the post-harvest performance of sweet pepper. However, the interaction of storage at 6.5°C and perforated polythene packaging produced the best results.
Aqueous compositions of hexanal, an inhibitor of phospholipase D, has been shown to enhance the shelf life and quality of fruits and vegetables. In the present study, sweet bell pepper fruit were exposed to hexanal vapor and its effect on quality attributes, shelf-life, and antioxidant enzyme activities were evaluated during storage at 7 day intervals for 21 d. Peppers subjected to hexanal vapor treatments (0.005, 0.01, and 0.02%, w/w) showed a significant (p < 0.05) delay in ripening process and preservation of postharvest qualities than untreated peppers, even at 21 d of storage. Treated fruit were characterized by increased firmness, a reduction in physiological water loss and lower electrical conductivity than control fruit, which indicated better membrane preservation. These treatments also resulted in an increase in the levels of antioxidant enzyme activities, specifically that of superoxide dismutase, catalase, glutathione reductase and guaiacol peroxidase. Evidences from the present study indicate that postharvest hexanal vapor treatment at optimal levels can effectively enhance the quality and shelf life of sweet bell peppers
In the present study, for the first time, we report the effectiveness of gibberellic acid (GA3) coating on the expansion of postharvest shelf-life in green chilli (Capsicum annum L.). The fruits were coated with GA3 dipping in 1, 2 and 3 ppm for 30 s and then stored at 4 ± 1 °C. Fruits without any GA3 coating were considered as control. All the treated and control fruits were stored as such for 45 days and throughout the storage period (with every nine days intervals) the multiple enzyme and antioxidants (associated with storage) such as titratable acidity, ascorbic acid content, ferrous ion chelating activity, reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, hydroxyl radical scavenging activity, total phenolic content and enzymatic study of polyphenol oxidase and pectate lyase activity were assessed. The fruits coated with all three levels of GA3 showed a significant delay in change of skin colour, decline in titratable acidity, total phenolic and ascorbic acid content, increase in enzyme and antioxidant activities during the cold-storage in comparison to the control fruits. GA3, used as the coating in green chillis, eventually showed beneficial roles in decelerating the mechanism of ripening. The results further indicated that the 2 ppm of GA3 concentration served superiorly than the 1 ppm or 3 ppm throughout storage and provided expanded shelf-life of green chilli.
The objective of this study was to evaluate the qualitative and quantitative composition of the phenolic compounds and the antioxidant activity of B. microphylla fruit under different light intensities and levels of fertilization during two production years. Total monomeric anthocyanin concentration in high light intensity conditions was three times more than that obtained at medium light intensity, expressed for both fresh weight and dry weight terms (299.7 mg/100 g FFW and 9.5 mg/g DFW, respectively). However, in the case of total polyphenol concentration, minor increases of 30 and 11% appeared under high light intensity in comparison with medium light intensity (906.6 mg/100 g FFW and 30.7 mg/g DFW, respectively). Scavenging activity on DPPH was increased from 56.0 to 66.8% under the high light intensity treatment. This was also true for the reducing power which increased from 40 to 46.2%. Fertilizers reduced the flavonoid concentration, but increased the total polyphenol concentration at fertilization level 2. In the case of flavonoids, the maximum contents in fruits were 200.2 and 7.6 mg (+)-catechin equivalents/100 g FFW and DFW, respectively in the control treatment. The total polyphenol concentration was the highest (856.1 and 31.2 mg tannic acid equivalents/g FFW and DFW, respectively) with the level fertilization 2. The scavenging activity on DPPH was from 60.3 to 62.8% when raising the fertilization level from 0 to 2, while the reducing power varied between 40.5 and 44.3% at levels 1 and 2. The total monomeric anthocyanin concentration increased with the level of fertilization in the fruits of plants at high light intensity, whereas the trend was inversed in those under medium light intensity. Hence, these studies display the possibility for maximizing both the productivity and the antioxidant capacity of fruits by crop management.
The antioxidant and enzyme inhibitory properties of methanolic extracts from four aromatic plants used in traditional medicine and food [Calamintha nepeta (L.) Savi subsp. nepeta, Helichrysum italicum subsp. picardii Franco, Mentha spicata L. and Origanum vulgare subsp. virens (Hoffmanns. & Link) Bonnier & Layens] were evaluated. The extract from O. vulgare exhibited the strongest DPPH (IC50 of 4.65 ± 0.12 µg/ml) and ABTS (1479.56 ± 12.29 µmolTE/gextract) scavenging capacities, as well as the largest ferric reducing ability (1746.76 ± 45.11 µmolAAE/gextract). This extract also showed the highest total phenolic content (1597.20 ± 24.10 µmolGAE/gextract) and although HPLC–DAD analysis revealed rosmarinic acid as the main compound of the extract, other compounds seem to be involved in the antioxidant activity. Furthermore, the extract from H. italicum, which was found to be rich in caffeoylquinic and dicaffeoylquinic acids and in pinocembrin, showed the highest inhibitory potential against acetylcholinesterase, tyrosinase and α-glucosidase. Overall, the results obtained validate the usefulness of the studied plants as valuable sources of natural agents beneficial for human health.
Sugarcane molasses is a wealthy source of health beneficial phenolic compounds and exhibited significant biological properties. Present study was designed to assess the inhibitory effect of sugarcane molasses on α-glucosidase and α-amylase. Hypoglycemic fractions were extracted using macro-porous and ion exchange resins. The total phenolics content was 0.179 ± 0.003 mg GAE per milligram of extract. Four phenolic acids which include caffeic acid (11.64 mg/g), ferulic acid (10.49 mg/g), chlorogenic acid (1.77 mg/g), and gallic acid (0.87 mg/g) were identified and quantified by high-performance liquid chromatography. The inhibitory activities of sugarcane molasses were 4.693 mg/mL (Km = 1.099 mL/mg) and 4.254 mg/mL (Km 0.238 mL/mg) for α-glucosidase and α-amylase, respectively, which revealed that sugarcane molasses could be a useful addition in medicinal preparations as nutraceutical and functional food for diabetic patients.
The effect of preharvest gibberellic acid treatments with the dose of 10, 20 and 30 ppm on Aksehir Napolyon sweet cherry were compared with control during 4 weeks storage. The most important problem of sweet cherry is decolouration of stem after storage. Different preharvest treatments can be effective to stop or slow down decolouration. In this research fruit firmness, titrable acidity, total soluble solids, stem colour (1-3 scale), weight losses and fruit decay were evaluated depend on different concentrations of gibberellic acid. The application of gibberellic acid decreased the loss of fruit firmness, delayed stem decolouration and maintained the brightness during storage compared with control and the other application rates.
Gibberellic acid (GA3) was applied in the orchard both to delay ripening and to prolong the potential storage life of 'Flamekist' nectarines. Treatments were applied at various times during and after pit hardening at doses ranging from 33 to 100 mg l-1 a.i. Effective treatments delayed fruit ripening on the tree, measured by the retardation of the change in fruit ground colour and the development of blush. The rates of fruit softening and loss of acidity were also retarded, but the soluble solids content (SSC) was not affected. Three applications of GA3 during fruit development or one application at the termination of pit hardening increased the percentage of fruits with no storage disorders following five or six weeks' controlled atmosphere storage. To our knowledge, this is the first report on the ability of GA3 to prevent physiological storage disorders in stone fruits.
Different concentrations of aminoethoxyvinylglycine (AVG) and gibberellic acid (GA3) and their combinations, applied at two stages of fruit growth, were evaluated for prolonging the marketing season of 'Feicheng' peaches. GA3 applied at the end of pit hardening, or AVG applied two weeks before commercial harvest, inhibited fruit maturation on the tree, delayed harvest and reduced flesh browning after cold storage in a concentration-dependent manner. A synergistic effect was found when both GA3 and AVG were used, with the combination of 100 or 150 mg l-1 GA3, applied at the end of pit hardening, and 100 mg l-1 AVG, applied two weeks before harvest giving the best results. These combinations retarded the change in ground colour, loss of firmness, and reduction in acidity by 2-3 weeks. Since harvest was prolonged by 2-3 weeks, soluble solids content (SSC) in fruit increased compared with the control (harvested earlier). Fruit size was significantly greater on treated trees compared with the controls when fruit set was controlled to the same level by hand thinning. After four weeks of storage and 4 d at 20°C, 83% of control fruit developed tissue browning, but only 5% of AVG + GA3-treated fruit developed browning after six weeks of storage and 4 d at 20°C. Thus, the marketing season of 'Feicheng' peaches was prolonged by at least four weeks by 100 or 150 mg l-1 of GA3 and 100 mg l-1 of AVG. Fruit treated with 150 mg l-1 GA3 plus 100 to 150 mg l-1 AVG showed similar results but failed to ripen properly after cold storage.
To test the effectiveness of different bioregulators in enhancing hell pepper (Capsicum annuum L.) yield and fruit quality, the commercial bioregulators CCC, NAA, GA3, and Biozyme® were sprayed on plants at flower initiation, followed by two additional applications at 30-day intervals. Biozyme produced a significant increase in total yield but ≃40% of the fruit were not marketable. Treatment with NAA produced the highest yield of marketable fruit. Treatments did not affect fruit firmness compared to the control. Gibberellic acid increased fruit ascorbic acid and citric acid concentrations and Biozyme, GA3, and CCC increased fruit soluble solids content. Biozyme treatment increased fruit fructose, sucrose, carotenoid, and lycopene concentration. Treatments had no effect on fruit calcium concentration or pH. Chemical names used: chlormequat chloride (CCC); naphthaleneacetic acid (NAA), gibberellic acid (GA3); GA3 + IAA (indole-3-acetic acid) + zeatine + micronutrients (Biozyme®).
Gibberellic acid (GA3) increases juice yield of processing oranges, but results are inconsistent. Preliminary research suggested that this variability might be related to application timing. Therefore, we conducted an experiment to determine the optimal time to apply GA3 for increasing juice yield of 'Hamlin', 'Pineapple', and 'Valencia' sweet oranges [Citrus sinensis (L.) Osb.]. Mature trees of each cultivar were sprayed with ≈10 L of a solution of GA3 (45 g.ha-1 a.i.) and organo-silicone surfactant (Silwet, 0.05%) between 2 Sept. and 9 Dec. 1998, and 25 Sept. and 9 Dec. 1999, or remained non-sprayed (control). Generally, the earliest application dates were most effective at maintaining peel puncture resistance above that of control fruit, while the latest application dates resulted in the most green peel color at harvest. Juice yield of 'Hamlin' and 'Valencia', but not 'Pineapple', was increased by GA3 at some application timings and harvest dates in both years. The increase in juice yield was related to time between application and harvest; juice yield of 'Hamlin' was greatest ≈2 months, and 'Valencia' ≈5 months after GA3 application. Treated fruit often had lower juice Brix than non-sprayed fruit, a phenomenon that often paralleled treatment effects on peel color. When treatments did not increase juice yield but reduced juice Brix, then yield of solids was sometimes lower than for non-treated fruit. Treatments generally delayed flowering of 'Pineapple' and 'Valencia' but not 'Hamlin'.
Apples, cv. Golden Delicious were subjected to ten preharvest sprays of 1.2% CaCl2 at weekly intervals. At the beginning of the climacteric stage, the fruits were harvested and sorted to small (4–5 cm dia.) and average (6–7.5 cm dia.) sizes, and stored at ambient conditions (25°C). The firmness of small fruits was higher than average ones. Application of CaCl2 resulted in higher flesh firmness at the time of harvest in average fruits but showed no significant changes in small ones. However, after three weeks of storage, both average and small fruits were showing better retention of firmness by CaCl2 treatment. Thus, preharvest treatment of CaCl2 may not necessarily always lead to firmer fruits at the time of harvest but may result in better retention of firmness during storage. The results are discussed in relation to cell-wall yield, β-D-galactosidase activity, total, free, ionically associated and covalently bound pectins, and hemicellulose contents. The differences in behaviour of average and small fruits to calcium application seem to be associated with the calcium content of covalently bound pectin fraction of the walls.
Castilleja tenuiflora, a species highly valued for its medicinal properties, is threatened in the wild. We evaluated the effects of six different immersion cycles in a temporary immersion bioreactor on C. tenuiflora shoot growth, proliferation rate, phenolics content, flavonoid content, and antioxidant activity. We also evaluated the regeneration capacity of the shoots. The highest proliferation rate (nine shoots per explant) was obtained using an immersion cycle of 5 min every 12 h, and the longest shoots (38.8 +/- 1.9 mm) were obtained using an immersion cycle of 5 min every 24 h. Shoots obtained from immersion cycles of 30 min every 24 h or 5 min every 24 h showed 100% rooting efficiency. Shoots obtained from immersion cycles of 30 min every 3 h or 30 min every 12 h accumulated H2O2, developed abnormal stomata, and showed symptoms of hyperhydricity. These characteristics were associated with a low survival rate (16-80%) when the plants were transferred to potting mix. The shoots from an immersion cycle of 30 min every 24 h showed the highest total phenolics content, which coincided with the highest antioxidant activity in the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) free-radical scavenging assay (161.74 +/- 10.06 mu mol Trolox/g dry weight (DW)). The shoots from an immersion cycle of 5 min every 24 h showed the highest activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging assay, and those from an immersion cycle of 5 min every 3 h showed the strongest reducing power. These results show that temporary immersion culture represents a reliable and efficient method for in vitro micropropagation of C. tenuiflora.
Three sesquiterpene lactones [two germacranolides (micranthin and sintenin) and one guaianolide (4β,10α-dihydroxy-5β,7β,8βH-guaia-1,11(13)dien-12,8α-olide)] and four derivatives of 3-methoxy flavones (santin, quercetagetin-3,6,3'-trimethyl ether, quercetagetin-3,6-dimethyl ether, and 5,7 dihydroxy 3,3',4'-trimethoxy flavone) were isolated from the ethyl acetate extract (EAE) of the aerial parts of Achillea biebersteinii Afan. (Asteraceae). Evaluation of protective and therapeutic effects of EAE against ethanol-induced gastric ulcer in rats was carried. Antiulcer activity evaluation was done through measuring ulcer indices, stomach acidity, gastric volume and lesion counts. Oxidative stress markers; malondialdehyde, glutathione and superoxide dismutase were also estimated. The work was extended to determine the histopathological assessment of the stomach. Gastric ulcer exhibited a significant elevation of the ulcer index and oxidative stress markers. The extract attenuated these increments and recorded protective and therapeutic effects against gastric ulcer. Hyperglycaemia increases the mucosal susceptibility to ulcerogenic stimuli and predisposes gastric ulceration. In vitro α-amylase inhibitory assay was applied to evaluate the post prandial antihyperglycaemia activity. The result showing that the EAE has the ability to reduce starch-induced postprandial glycaemic excursions by virtue of potent intestinal α-amylase inhibitory activity. These findings demonstrated the remarkable potential of A. biebersteinii as valuable source of antiulcer agent with post prandial hyperglycaemia lowering effect.
Physical characteristics [initial water content, surface area, surface area: volume (SA: V) ratio, cuticle weight, epicuticular wax content, and surface morphology] were examined to determine relationships between physical properties and water-loss `rate in pepper fruits. `Keystone', `NuMex R Naky', and `Santa Fe Grande' peppers, differing in physical characteristics, were stored at 8, 14, or 20C. Water-loss rate increased linearly with storage time at each temperature and was different for each cultivar. Water-loss rate was positively correlated with initial water content at 14 and 20C, SA: V ratio at all temperatures, and cuticle thickness at 14 and 20C. Water-loss rate was negatively correlated with surface area and epicuticular wax content at all temperatures. Stomata were absent on the fruit surface, and epicuticular wax was amorphous for each cultivar.
1999. The effect of preharvest foliar sprays of calcium on quality and shelf life of two cultivars of sweet bell peppers (Capsicum annuum L.) grown in plasticulture. Can. J. Plant Sci. 79: 411–416. The effect of preharvest calcium sprays on postharvest quality of sweet bell peppers grown in plasticulture was studied. Calcium was applied as three sprays of 0.4% (wt/vol) CaCl 2 in water to plots of Oriole and Bell Boy peppers in each of 2 yr. Fruit weight, water loss, firm-ness, decay and the composition of the pectic fractions were determined at harvest and during storage. Preharvest sprays of CaCl 2 increased the weight of fruit for Oriole, improved firmness retention in storage, decreased decay, increased pericarp wall thickness and the insoluble pectic fractions of both cultivars but had no effect on water loss in storage. The results suggest that Ca improves firmness retention through enhancing the pectic composition of cell walls and pericarp wall thickness. Effects of Ca sprays on reducing decay could not be attributed to factors measured in this work. Preharvest foliar sprays of CaCl 2 show promise in reduc-ing postharvest decay and improving firmness retention in sweet bell peppers grown under plasticulture.
Aloe species are highly-prized for their ornamental value and have been utilized for centuries in traditional medicine. Due to their habitat loss and exploitation for medicinal and ornamental plant trade, many species in this genus have become threatened. One of the most important globally rated medicinal species in Aloe genus is A. arborescens. The current study evaluated the roles of different aromatic cytokinin types and concentrations on direct organogenesis, in vitro bioactive secondary metabolite production and antioxidant activity of regenerated shoots of A. arborescens. There was an increase in the number of adventitious shoots produced per explant with an increase in concentration in cultures treated with meta-topolin (mT), meta-topolin riboside (mTR), meta-methoxytopolin (MemT) and benzyladenine riboside (BAR), reaching an optimum at either 5.0 or 7.5 μM. Overall, the treatment with 5.0 μM mT gave the largest number of transplantable shoots (regenerated shoots with length greater than 10 mm). Rooted shoots were successfully acclimatized after 8 weeks with a survival frequency above 90 % and no observable morphological abnormalities. Variable amounts of total iridoids, phenolics, flavonoids and condensed tannins were detected in regenerated shoots from all the cytokinin treatments. An increased free-radical scavenging activity with an increase in concentration was recorded in regenerated shoots from mT and mTR treatments, reaching an optimum at 7.5 μM concentration. The present study shows that the choice of cytokinin type and concentration exogenously supplied during tissue culture markedly influences not only shoot proliferation but also the in vitro production of bioactive secondary metabolites.
C. Henríquez, R. González and C. Krarup. Heat treatments and progression of chilling injury and pigmentation of tomatoes during postharvest. During two seasons fruit of tomato (Lycopersicon esculentum Mill.) cv. Dominique (R593), harvested in early autumn at maturity stage turning, were subjected to different heat treatments before storage at 2 ºC to evaluate progression of chilling injury and pigmentation. In the first season heat treatments in air (24 h at 38 ºC, 6 h at 42 ºC h) or in water (2 min at 48 ºC, 2 min at 50 ºC and 15 min at 40 ºC) were compared with a control kept at 20 ºC before storage. After 14 days at 2 ºC and after additional 3 days at 20 ºC, results showed significant differences in fruit pitting but other symptoms were unaffected and, overall, the best treatment (6 h at 42 ºC) had only a marginal effect on inhibition of chilling injury. In the second season, heat treatments in air (6, 12, 24, 48 or 96 h at 42 ºC) were compared with a control kept at 20 ºC after different periods at 2 ºC. Degradation of chlorophyll either during or after the heat treatments was unaffected while lycopene synthesis in relation to the control was arrested in all cases. Again, the overall effect of the heat treatments on progression of chilling injury at 2 ºC was only marginal.
The aim of the experiment was to examine the effects of foliar applications of calcium (Ca) and boron (B) on yield and fruit quality of “Elsanta” strawberries grown on a sandy loam soil with low status of available B. The study was conducted in 1999–2000 at a commercial strawberry plantation in Central Poland. Cold‐stored strawberries were planted in 1998 at a spacing of 0.25 × 0.8 m. The following treatments were applied: (i) five sprays of Ca as CaCl2 at a rate of 1.5 kg Ca ha spray with addition of Tween 20 adjuvant at 0.1%; the first spray was performed at the petal fall stage and the next at 5‐day intervals; (ii) three sprays of B as Borvit material at a rate of 160 g B ha spray at the beginning of flowering and 5, and 10 days later; (iii) sprays of B and Ca as in the combination of (i) and (ii). Plants sprayed with water served as the control. Results showed that fruit and leaves from Ca‐treated plants had increased Ca concentrations. Sprays with B increased status of this microelement in fruit and leaf tissues. Treatments did not affect total and marketable fruit yield, mean berry weight, the number deformed fruit, soluble solids concentration and titratable acidity of fruit at harvest. Fruit sprayed with Ca or B plus Ca were firmer and more resistant to Botrytis rot at harvest and after 3 days of holding at 18°C compared to those of control plots. Moreover, sprays of Ca or B plus Ca increased soluble solids concentration and titratable acidity of fruit after 3 days of holding at room temperature. These results indicate that sprays of CaCl2 with addition of Tween 20 should be recommended to improve quality and shelf‐life of strawberry fruit, particularly in proecological production where application of fungicides is restricted.
