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... Adventitious shoots may be normal part of plant development to existing primary shoot (additive root-sprouting according to Rauh (1937) does not occur necessarily in all individuals in a population or in all populations of a species) or could be only induced by damage in plants otherwise using AMs for branching [regenerative root-sprouting according to Rauh (1937)]. A third possibility is that the primary shoot does not develop at all or only partly so that no AMs are preserved for further plant development and adventitious sprouting is necessary for the plant to complete the life cycle and to produce seeds (necessary root-sprouting, Rauh, 1937). ...
... Adventitious shoots may be normal part of plant development to existing primary shoot (additive root-sprouting according to Rauh (1937) does not occur necessarily in all individuals in a population or in all populations of a species) or could be only induced by damage in plants otherwise using AMs for branching [regenerative root-sprouting according to Rauh (1937)]. A third possibility is that the primary shoot does not develop at all or only partly so that no AMs are preserved for further plant development and adventitious sprouting is necessary for the plant to complete the life cycle and to produce seeds (necessary root-sprouting, Rauh, 1937). ...
... Adventitious shoots may be normal part of plant development to existing primary shoot (additive root-sprouting according to Rauh (1937) does not occur necessarily in all individuals in a population or in all populations of a species) or could be only induced by damage in plants otherwise using AMs for branching [regenerative root-sprouting according to Rauh (1937)]. A third possibility is that the primary shoot does not develop at all or only partly so that no AMs are preserved for further plant development and adventitious sprouting is necessary for the plant to complete the life cycle and to produce seeds (necessary root-sprouting, Rauh, 1937). In some genera, we can observe a negative correlation between the development of primary shoots and adventitious sprouting (Rauh, 1937) from species with a dominant primary shoot during their whole lifespan and producing adventitious shoots only after injury, through to species whose primary shoots flower and later in ontogeny are replaced by additive adventitious shoots, and to species with a poorly developed primary shoot that are dependent on necessary adventitious shoots (e.g. ...
Classical models of tree architecture are based on the development of aboveground stem branching in an ideal tree from early ontogeny to the first flowering. Such attempts hinder the usage of architectural traits for understanding plant ecology, especially for herbs. In this article, the author discusses belowground plant architecture, especially the root system, and its contribution to whole plant architecture during ontogeny and after damage.
... Sprouting from roots may be an adaptation to severe and recurrent damage because bud formation on roots is often Downloaded from https://academic.oup.com/aob/article/127/7/931/6146818 by guest on 20 March 2023 initiated by damage or fragmentation of the root system (Rauh, 1937;Klimešová et al., 2017). However, root sprouting (RS) is not always conditioned by injury and even occurs spontaneously, as part of normal development (Wittrock, 1884;Rauh, 1937). ...
... Sprouting from roots may be an adaptation to severe and recurrent damage because bud formation on roots is often Downloaded from https://academic.oup.com/aob/article/127/7/931/6146818 by guest on 20 March 2023 initiated by damage or fragmentation of the root system (Rauh, 1937;Klimešová et al., 2017). However, root sprouting (RS) is not always conditioned by injury and even occurs spontaneously, as part of normal development (Wittrock, 1884;Rauh, 1937). Previous studies on the distribution of RS species report them most commonly from disturbed habitats (Guerrero-Campo et al., 2006;Klimešová et al., 2008), but they are by no means restricted to them. ...
... Many RS species belong to expansive weeds (e.g Cirsium arvense, Sonchus arvensis or Convolvulus arvensis; Raju et al., 1966;Liew et al., 2013), clonal plants of open habitats, (e.g. Linaria vulgaris and Rumex acetosella; Rauh, 1937), in forest understorey (e.g. Rubus) or forming large forest stands (e.g. ...
Background and Aims
Root sprouting (RS), i.e. the ability to form adventitious buds on roots, is an important form of clonal growth in a number of species, and serves both as a survival strategy and a means of spatial expansion, particularly in plants growing in severely and recurrently disturbed habitats. Occurrence and/or success of plants in severely and recurrently disturbed habitats are determined by two components, viz.; the ability to produce adventitious buds on roots and the vigour of their production. As mechanisms behind different magnitudes of RS remain unclear, our study investigates: (i) whether the presence or absence of specific tissues in roots can promote or limit RS, and (ii) whether there is some relationship between RS ability, RS vigour and species niche.
Methods
We studied RS ability together with RS vigour in 182 Central European herbaceous species under controlled experimental conditions. We used phylogenetic logistic regressions to model the presence of RS, RS vigour, the relationship between RS and anatomical traits, and the relationship between RS and parameters of species niche.
Key Results
One quarter of herbs examined were able to produce adventitious buds on roots. They were characterized by their preference for open dry habitats, the presence of secondary root thickening and the occurrence of sclerified cortical cells in roots. Root sprouting vigour was not associated with any specific anatomical pattern but was correlated with the environmental niches of different species, indicating that preferred disturbed and dry habitats might represent a selection pressure for more vigorous root sprouters than undisturbed and wet habitats.
Conclusions
Our study shows that sprouting from roots is quite common in temperate dicotyledonous herbs. Two components of RS, ability and vigour, should be considered separately in future studies. We would also like to focus more attention on RS in herbs from other regions as well as on external forces and internal mechanisms regulating evolution and the functions of RS in both disturbed and undisturbed habitats.
... Röper, in her Enumeratio Euphorbiarum from 1824, reported rare sprouting from the hypocotyl in injured Euphorbia lathyris and E. exigua (Bernhardi 1832). Other species were added to the list among others by Wittrock (1884) and Beijerinck (1887, see also Appendix 1), and the century of effort to understand the morphological nature of adventitious sprouting was crowned by the monographic study of Rauh (1937). Rauh (1937) observed the growth of numerous plants in experiments, described their ontogeny and precisely categorized the roles of adventitious sprouting in the plant life cycle. ...
... Other species were added to the list among others by Wittrock (1884) and Beijerinck (1887, see also Appendix 1), and the century of effort to understand the morphological nature of adventitious sprouting was crowned by the monographic study of Rauh (1937). Rauh (1937) observed the growth of numerous plants in experiments, described their ontogeny and precisely categorized the roles of adventitious sprouting in the plant life cycle. Besides root sprouting induced by injury, described already by Wittrock (1884) as 'regenerative root sprouting', Rauh recognized two other categories. ...
... Plants found to be root-sprouters were classified according to Rauh (1937) as regenerative, facultative, or obligate, depending on the role root sprouting plays in their life cycle (Fig. 1). Furthermore, the location of adventitious buds and/or shoots on the hypocotyl, the main root or lateral roots was recorded. ...
The production of shoots from roots (adventitious bud and shoot formation, root sprouting) first attracted attention in the 19th century as a morphological rarity. At that time, the first checklists of plants capable of root sprouting were compiled. Since then, experiments have proven that the ability to produce buds on roots serves the purpose of bud bank formation or represents a mode of clonal growth. The former enables resprouting after injury whereas the latter facilitates foraging for nutrients and vegetative multiplication. However, only a small proportion of root-sprouters have been studied so far, and for most of them we lack detailed data on the anatomy, morphology, ecology and physiology of adventitious shoot formation. These knowledge gaps hinder further understanding of their ecology and evolution. To support researchers interested in adventitious bud and shoot formation in any field of plant science, we compiled a list of plants considered capable of root sprouting based on the literature and the CLO-PLA database for the flora of the Czech Republic. Here we provide basic comparisons concerning the distribution of root sprouting ability among life history types, plants differing in rarity and invasive status, and taxonomic groups. Altogether 342 plant species are reported to be root-sprouters, i.e. 10% of the Czech flora. Root-sprouters are most commonly found among woody plants, less so among non-clonal perennial herbs, biennials and clonal herbs, and least commonly among annuals. Root-sprouters are more common among alien plants (especially woody ones) than among red-listed plants. Root sprouting usually plays a supplementary (facultative) or regenerative role in the plant life cycle. Root-sprouters occur in 64 families, mostly of dicots. The greatest number of root-sprouters belong to the Asteraceae and Rosaceae families (41). We have only rudimentary information on 145 species out of the 342 (42%) species that are regarded as root-sprouters.
... These modules are iterated both due to growth of the apical meristem, which leads to elongation of the main shoot, and due to growth of axillary meristems, which produce new branches (shoots of higher orders). While this modular plan is responsible for the plant architecture in the majority of plants, there are also plants with a nonconventional architecture, which are able to produce new shoots via formation of adventitious buds on roots and/or on the hypocotyl, i.e. otherwise bud-free organs (Rauh 1937). By sprouting directly from the root system, growth (including clonal growth) of these plants is potentially independent of the axillary buds on the stem and thus represents an alternative route to clonal multiplication and vegetative regeneration (Peterson 1975;Groff and Kaplan 1988;Klimešová and Martínková 2004). ...
... Although there is a number of studies on root-sprouting plants (root spouting is abbreviated below as RS) (Korsmo 1930;Rauh 1937;Raju et al. 1966;Del Tredici 2001;Guerrero-Campo et al. 2006;Ferreira et al. 2015), this phenomenon has never been systematically analysed from an evolutionary nor an ecological perspective. In the only flora having a checklist of plants capable to form adventitious buds and sprout from roots (Czech Republic; Bartušková et al. in press), the proportion of root-sprouters is about 10%. ...
... Before ecologists began to pay attention to it (see below), RS had for a long time been considered to be just a morphological curiosity (Wittrock 1884;Beijerinck 1887;Rauh 1937; but see Arber 1950) or a teratological feature (Penzig 1921(Penzig -1922. This was due to the observation that resprouting from roots is often enhanced by mechanical injury to the plant. ...
We address the neglected issue of ecological and evolutionary significance of root sprouting (RS) in plants. RS has been considered a sort of morphological curiosity. However, existing data of the Central European flora show that it occurs in about 10% of species. These species are therefore independent of a stem-derived bud bank in their resprouting. As sprouting from roots has been hypothesised to help plants survive disturbance, we used a large data set (2914 species with data on presence/absence of RS from Central Europe) to perform comparative analyses of its occurrence in disturbed habitats, evolution of RS in response to disturbance, and its distribution among individual plant lineages. To address these questions, we linked the data with species-level indicator values for disturbance, data on additional functional traits and phylogenetic data. We confirmed that RS ability is more frequent in plants growing in habitats subjected to disturbance, especially in annuals and clonal species. This contrasts with clonality via stem-based organs, which does not promote occurrence in disturbed habitats. Disturbance severity is the most important factor determining RS species distribution, whereas disturbance frequency plays a smaller role. RS is phylogenetically less conservative than sprouting from the stem-based belowground bud bank and thus can be easily acquired or lost in evolution, although these rates strongly differ between individual lineages. Evolution of RS seems to be driven largely by occurrence in disturbed habitats, and has appeared/disappeared independently of the presence of a stem-derived bud bank. Importantly, the data support the scenario in which colonisation of such habitats occurs prior to acquiring the RS ability, which develops only later. RS is hence a more important ecological trait than hitherto assumed. It constitutes an independent route of response to severe disturbance and its ecological effects and evolutionary patterns differ from stem-based clonality.
... Plants carrying this trait have a potential bud bank that gets initiated after injury to overcome meristem limitation after severe damage and to facilitate regeneration . Root sprouting is concentrated in some taxonomic groups and missing in others (Rauh 1937), which makes it difficult to assess the evolutionary significance of this trait. Plant species able to resprout from roots have inherited this trait from an ancestor or possess it as an adaptation to past or current conditions. ...
... Plant species able to resprout from roots have inherited this trait from an ancestor or possess it as an adaptation to past or current conditions. Moreover, the anatomy, morphology and ecology of adventitious sprouting differ depending on the taxonomic group (Rauh 1937;Klimešová and Martínková 2004;Klimešová 2007), so it has probably arisen from independent evolutionary events. Differences in the role of root sprouting also exist among related species, and these differences are particularly related to the plant life cycle (e.g. in members of Euphorbia L. and Linaria Mill., see Rauh 1937 for descriptions of the genera). ...
... Moreover, the anatomy, morphology and ecology of adventitious sprouting differ depending on the taxonomic group (Rauh 1937;Klimešová and Martínková 2004;Klimešová 2007), so it has probably arisen from independent evolutionary events. Differences in the role of root sprouting also exist among related species, and these differences are particularly related to the plant life cycle (e.g. in members of Euphorbia L. and Linaria Mill., see Rauh 1937 for descriptions of the genera). ...
Plants able to resprout from roots have a potential bud bank that gets initiated after injury to overcome meristem limitation after loss of all stem parts and to facilitate regeneration. Knautia arvensis is reportedly able to sprout from its roots on arable land, but information is missing regarding such ability in serpentine populations or how it might differ between diploids and tetraploids. We hypothesized that (1) ‘ruderal’ non-serpentine populations better tolerate severe disturbance than relic, serpentine ones; (2) tetraploid populations resprout more readily than diploids due to enhanced growth of higher ploidy levels; and (3) plants of different ploidy levels from serpentine soils are, for evolutionary reasons, more similar in their response to disturbances than plants from non-serpentine soils. To test these hypotheses, we conducted a pot experiment. Its results do not support our hypothesis that the ability to sprout from roots is a factor driving the spread of new weedy taxa into central Europe or the hypothesis that it is related to polyploidization in the genus Knautia. Both tetraploids and plants from non-serpentine populations regenerated less vigorously than diploids and plants from serpentine populations. However, the genetically closer populations of serpentine origin were more similar in their response to experimental manipulations than their genetically distinct non-serpentine counterparts. The success of non-serpentine taxa in disturbed habitats of central Europe might be related to traits other than the ability to resprout.
... However, there are some internal factors that can freeze resprouting after disturbance or decrease its rate (Dubard, 1903;Martı´nkova´et al., 2004a, b;Martı´nkova´et al., in prep.;Peterson, 1975;Rauh, 1937). It was found that a more advanced life-cycle phase at the time of injury and higher disturbance severity decrease either the probability of successful resprouting or regrowth in annual and biennial species (Martı´nkova´et al., 2004a, Martı´n-kova´et al., in prep.). ...
... We chose as a model for this study a common biennial species of man-made habitats, O. biennis, in which ability of resprouting after a severe disturbance has been documented (Klimesˇova´, 2003;Martı´nkova´et al., 2004a;Rauh, 1937), and its closely related congeners O. fallax and O. glazioviana, about which no literature information on their resprouting abilities existed. Since habitats occupied by all these Oenothera congeners are frequently disturbed, and thus not suitable for longer field experiments, manipulative garden experiments are necessary to evaluate the effects of timing and severity of injury on the resprouting ability in these Oenothera species. ...
... In the present experiment, no young vegetative rosettes regenerated from roots, and regeneration of reproducing plants and overwintered rosettes was exceptional. Rauh (1937) found a successful regeneration from root buds only in vegetative plants of O. biennis. Martı´nkova´et al. (2004a) reported a relatively high probability of regeneration after injury from root buds in both vegetative and reproductive plants of O. biennis. ...
It has been recently shown that some annual and biennial species of man-made habitats cope with severe disturbance by resprouting (vegetative regeneration) from their bud bank and do not only rely on regeneration from seeds. Nevertheless, information on the ecology of this phenomenon is rare. In a field study, we answered the question how frequent is resprouting from root buds in populations of the ruderal biennial herb Oenothera biennis, and how it is affected by habitat conditions. In an experiment, we tested the hypothesis that higher severity of injury and later life-cycle phase of the injured plants suppress resprouting from both axillary and root buds in O. biennis and also in its closely related congeners O. fallax and O. glazioviana.
... Independent formation of adventitious meristems by dedifferentiation of already differentiated tissue might protect a plant from mutations occurring in primary and/or axillary meristems, and it can also provide meristems when all stem parts (with all their SAMs and AMs) are lost to damage or are undeveloped (e.g. in mycoheterotrophs, Klime sov a, 2007). Such adventitious meristems are produced by c. 8% of the temperate flora (Klime sov a & de Bello, 2009), but individual species differ vastly in their abilities to form adventitious meristems and shoots and also in the roles that adventitious shoots play in their lives (Rauh, 1937;Fig. 2-5). ...
... In eudicots, woodiness is an ancient character, with clonality and monocarpic life history appearing later (Mogie & Hutchings, 1990). The ability to form adventitious buds is a recent innovation that has appeared many times in dicotyledonous herbs and thus shows low phylogenetic conservatism (see also Rauh, 1937). Interestingly, although forming adventitious meristems is an evolutionarily variable character usually responsible for clonal growth of dicotyledonous trees (Del Tredici, 2001), its role in preventing manifestation of senescence (genetic and other effects, see e.g. ...
We explore how plant morphology constrains renewal and replacement of modules in the plant body and further, we investigate the idea that most of the important morphological characteristics in relation to senescence are evolutionarily conservative, and therefore shaped by developmental constraints that are not easily overcome by selective forces.
Although plants are very flexible in production of new plant modules, continuous replacement of old modules is not a rule due to energy exhaustion in monocarpic plants and inability of some perennials to replace essential plant organs like trunk and/or main root in non-clonal plants.
Plant senescence was examined recently in several top journals (New Phytologist, Journal of Ecology, Nature) and the morphollgical constraints of modular plant growth were not taken into account. We believe considering morphological constraints of plant growth will help to ask proper questions in research of whole plant senescence.
... Anatomical studies of adventitious-bud formation on the hypocotyl of Linum usitatissimum L. (Adams 1924;Crooks 1933;Rauh 1937;Eggers 1946;Link and Eggers 1946;Ishikawa et al. 1997) show that sprouting ability diminishes with aging (Crooks 1933;Rauh 1937;Link and Eggers 1946). Moreover, biennials are able to postpone reproduction to the next season when there has been severe disturbance Martínková et al. 2008;Piippo et al. 2009), whereas strict annuals are not able to do so, and therefore, a late disturbance might hinder seed ripening despite successful regeneration of plants. ...
... Anatomical studies of adventitious-bud formation on the hypocotyl of Linum usitatissimum L. (Adams 1924;Crooks 1933;Rauh 1937;Eggers 1946;Link and Eggers 1946;Ishikawa et al. 1997) show that sprouting ability diminishes with aging (Crooks 1933;Rauh 1937;Link and Eggers 1946). Moreover, biennials are able to postpone reproduction to the next season when there has been severe disturbance Martínková et al. 2008;Piippo et al. 2009), whereas strict annuals are not able to do so, and therefore, a late disturbance might hinder seed ripening despite successful regeneration of plants. ...
Tolerance to very severe disturbance by the annual herb Euphorbia peplus L. was examined. We explored the role of disturbance timing, competition, and site productivity on the performance of disturbed plants. Ninety-three percent of disturbed plants survived following disturbance 14 d after plant emergence, whereas only 48% of disturbed plants survived disturbance 42 d after emergence. Early disturbed plants compensated for biomass loss and had higher fecundity than undisturbed plants, but this was not the case for plants that were disturbed at later times following emergence. Field assessment revealed that disturbed plants were, in general, of the same height as undisturbed plants, even under competition. Undisturbed plants had very conservative architecture across various conditions (competition and nutrients), whereas disturbed plants had more branched architecture under moderate competition and nutrient availability. Accordingly, we suggest that E. peplus utilizes a bet-hedging strategy where adventitious meristems are reserved for regrowth after a severe disturbance event that removes all dormant axillary meristems. Moreover, we propose that the tolerance to disturbance in short-lived species could play an important role in the ecology of disturbed communities. Finally, the tolerance to disturbance could be one of the prerequisites of invasibility of E. peplus in non-native ranges. We also speculate about the potential costs and benefits related with the tolerance to disturbance in short-lived species and about a mechanical control of E. peplus in invaded ranges.
... First, root tissue must be similar to callus tissue, which is sensitive to phytohormone signals; and second, this tissue must possess a source of undifferentiated cells available for differentiation to shoots or roots. These two conditions might be fulfilled by the lateral cambium in a secondarily thickened root (Bartušková et al., 2021), pericycle (Kerstetter and Hake, 1997) or callus tissue formed on a wounded root (Rauh, 1937). The idea that lateral cambium is the most suitable receptive tissue is supported by the fact that most root-sprouting plants are eudicots capable of secondary thickening, while other taxonomical groups that do not have secondary growth largely lack this ability (Bartušková et al., 2021). ...
Root sprouting (RS) species can regenerate from even small root fragments. The root buds are usually well protected against disturbance because they are deep in the soil, and injury oftentimes boosts root sprouting. Despite these obvious advantages, only 10% of plants exhibit RS ability. Are there specific ecophysiological barriers to RS ability? We set up a controlled experiment with ten congeneric pairs of herbs differing in RS ability and exposed them to severe aboveground biomass removal and assessed how RS and non-RS species differ in biomass production, root nitrogen and phosphorus content, and root tissue carbohydrate concentrations and whether phytohormone profiles explain variation in RS ability. No differences were observed in regenerated biomass three months after biomass removal, although RS species had lower root dry matter content, lower root nitrogen content, higher soluble sugar content, and a lower auxin-to-cytokinin ratio than non-RS species. RS and non-RS herbs differed in root tissue carbohydrate concentrations, which suggests that RS species, apart from having RS ability, might be better prepared for disturbance due to the availability of stored energy and carbon. Presumably, the key barrier to the more frequent occurrence of RS ability in the herbaceous plants studied here is a low auxin-to-cytokinin ratio, which is necessary to induce RS but is likely non-existent in most plants in order to avoid the risk of developmental deformities.
... Moreover, disturbance plays an important role in both the evolution of root sprouters and the occurrence of root sprouters along disturbance gradients (Bartu skov a et al. 2017; Klime sov a et al. 2017). Previous studies identified root buds and characterized their anatomy and ontogeny across different species (Rauh 1937;Dore 1955;Charlton 1965;Bonnett & Torrey 1966;Hamdoun 1970;Peterson 1975;Sharma et al. 1993;Fukuda et al. 2007). Other studies have investigated the regulatory mechanisms of bud dormancy in several weed and crop species (Horvath et al. 2003;Jia et al. 2006;Wan et al. 2006;Parveen & Shahzad 2011). ...
A bud bank is a pool of dormant meristems that enable plants to resprout after injury. While the bud bank on stem organs is established prior to injury as the stem grows, the bud bank on roots is considered at least partly formed as a response to disturbance events. To date, only woody species have been examined, and the establishment of reparative buds after injury without connection to the root vascular system has been confirmed; for herbs, no data are available. We tested whether root buds are formed spontaneously or induced after plant damage by studying root anatomy following plant injury in two congeneric perennial herbs.
In a pot experiment with young plants of Inula britannica (root sprouter) and I. salicina (non‐root sprouter), whole aboveground biomass was removed. Roots were sampled five times at 1‐week intervals after disturbance events to evaluate bud occurrence and size, root and vessel diameters, sclerenchyma areas and carbohydrate storage.
Compared to non‐root‐sprouting I. salicina, root‐sprouting I. britannica presented more secondary thickening that was connected to adventitious bud formation and improved the root storage and transport capacity necessary for resprouting. Plant injury, in contrast to expectations, did not cause increased bud formation in I. britannica, and all buds were connected to the root vascular system. No root buds were observed in I. salicina .
Our study implies that plants using bud banks on roots might depend on preformed buds. Comparative studies examining more species are needed to assess the generality of our findings.
... Nevertheless, there are short-lived herbs that regenerate after severe disturbances in which all axillary buds are removed or even after root system fragmentation (Martínková et al., 2006. This regenerative strategy is enabled by the resprouting of the plants from adventitious buds on the roots (Rauh, 1937;Bartušková et al., 2017). The extent of this ability varies among species and is influenced by several internal factors of the injured plant, e.g., its age, life-cycle phase, life-cycle mode, and stored reserves, as well as by external factors such as the severity and frequency of disturbance and the nutrient availability Malíková et al., 2010;Martínková et al., 2015;. ...
The predominance of short-lived species in disturbed habitats supports the view that generative regeneration is an advantageous strategy under these conditions. However, there are short-lived species that survive the destruction of aboveground biomass and resprout from roots. Yet, there is only limited knowledge on the effect of injury on the plant growth of individuals regrowing from roots, and nearly no research has been conducted on the physiological regulation of root-sprouting.
We experimentally tested the effect of total shoot biomass removal on the growth, root respiration and photosynthesis of the short-lived, root-sprouting herb Barbarea vulgaris (Brassicaceae) to assess the efficiency and importance of the root sprouting ability.
Regenerating plants compensated for the loss of photosynthetic area by producing a higher number of leaves with higher SLA, but we did not observe compensatory photosynthesis, which could potentially counterbalance the loss of photosynthetic area and allow accelerated growth. The root respiration rate significantly decreased immediately after injury and then slightly and consequentially increased. The belowground biomass of the injured plants decreased by more than four times a month after the injury comparing to the biomass measured immediately after the disturbance. This result suggests the intensive consumption of reserves located in roots, although the root respiration values did not indicate it.
Although we found physiological constraints that limited more vigorous resprouting, we conclude that the root-sprouting ability of short-lived species represents a useful strategy for population persistence in frequently disturbed habitats, in places lacking seed banks or when disturbances occur during less-than-suitable germination conditions.
... In a few taxa, the formation of root buds is necessary for completing the life cycle and flowering. They develop in all individuals, and survival/flowering or overwintering of an individual is dependent on them (Rauh 1937, Klimešová 2007. The data were taken from Bartušková et al. (2017). ...
The Pladias (Plant Diversity Analysis and Synthesis) Database of the Czech Flora and Vegetation was developed by the Pladias project team in 2014-2018 and has been continuously updated since then. The flora section of the database contains critically revised information on the Czech vascular flora, including 13.6 million plant occurrence records, which are dynamically displayed in maps, and data on 120 plant characteristics (traits, environmental associations and other information), divided into the sections: (1) Habitus and growth type, (2) Leaf, (3) Flower, (4) Fruit, seed and dispersal, (5) Belowground organs and clonality, (6) Trophic mode, (7) Karyology, (8) Taxon origin, (9) Ecological indicator values, (10) Habitat and sociology, (11) Distribution and frequency, and (12) Threats and protection. The vegetation section of the database contains information on Czech vegetation types extracted from the monograph Vegetation of the Czech Republic. The data are supplemented by national botanical bibliographies, electronic versions of the standard national flora and vegetation monographs, a database of more than 19,000 pictures of plant taxa and vegetation types, and digital maps (shapefiles) with botanical information. The data from the database are available online on a public portal www.pladias.cz, which also provides download options for various datasets and online identification keys to the species and vegetation types of the Czech Republic. In this paper, we describe the general scope, structure and content of the database, and details of the data on plant characteristics. To illustrate the data and describe the main geographic patterns in selected plant characteristics, we provide maps of mean values of numerical characteristics or proportions of categories for categorical characteristics on the map of the country in a grid of 5 longitudinal × 3 latitudinal minutes (approximately 6.0 km × 5.5 km). We also summarize the main variation patterns in the functional traits in the Czech flora using the principal component analysis.
... However, most of these methods do not allow the observation of belowground plant organs as a whole (e.g., fine and thick roots, rhizomes; Klimešová et al., 2018). Solutions to these challenges are becoming available based on past fundamental work (e.g., Rauh, 1937;Kutschera andLichtenegger, 1982, 1992;Bell, 1991), involving different ways of looking at plants, i.e., plants as modular organisms (Klimešová et al., 2019). ...
... Soboles formation is found in both woody and herbaceous representatives. According to Rauh's (1937) classification, this ability is compulsory in boths groups. In Ehretia acuminata and E. corylifolia, roots do not start producing adventitious buds until at least the 6 th year of the seedling's life (Barykina 2012). ...
14 species of Boraginaceae were studied to reveal the diversity of vegetative propagation modes, connected with adaptation to habitats and different strategies of exploring, expanding to and populating new sites of growing space ('attached' and 'creeping' forms). The main one is sarmentation, accompanied by the formation of sprouts originating from roots (soboles) or shoots. A certain correlation between sarmentation types and the plant's life form, shoot structure and root system type is shown. Tap-rooted woody biomorphs are known to propagate by means of sobole formation. Perennial herbaceous plants, in the vast majority with short tap root or fibrous root systems, appear to demonstrate a huge variation in sarmentation types. It is performed by means of sobole formation as well as through the separation of parts of underground epigeogenous, hypogeogenous and epigeogenous-hypogeogenous rhizomes, aerial rhizomes, specialized procumbent stolon-like biennial shoots as well as by tubers. The ability to form vegetative diaspores is determined by the microstructure of metamorphosed organs of reproduction, i.e. marked parenchyma development, extensive supply of ergastic substances (starch, aleurone), poor lignification and lack of supporting tissues and cork (excluding Ehretia, Mertensia); the protective function is performed by metacutinized peripheral bark layers and wide dead leaf bases. Specialized organs of vegetative propagation are also characterized by accelerated differentiation and development, short-term activity of the vascular cambium, their fast renewal and additional increased ability to produce adventitious buds and roots. The revealed diversity of vegetative dispersal and propagation ways facilitated the successful expansion of Boraginaceae into various ecological niches in the vegetation of subtropical and tropical areas.
... Soboles formation is found in both woody and herbaceous representatives. According to Rauh's (1937) classification, this ability is compulsory in boths groups. In Ehretia acuminata and E. corylifolia, roots do not start producing adventitious buds until at least the 6 th year of the seedling's life (Barykina 2012). ...
14 species of Boraginaceae were studied to reveal the diversity of vegetative propagation modes, connected with adaptation to habitats and different strategies of exploring, expanding to and populating new sites of growing space ('attached' and 'creeping' forms). The main one is sarmentation, accompanied by the formation of sprouts originating from roots (soboles) or shoots. A certain correlation between sarmentation types and the plant's life form, shoot structure and root system type is shown. Tap-rooted woody biomorphs are known to propagate by means of sobole formation. Perennial herbaceous plants, in the vast majority with short tap root or fibrous root systems, appear to demonstrate a huge variation in sarmentation types. It is performed by means of sobole formation as well as through the separation of parts of underground epigeogenous, hypogeogenous and epigeogenous-hypogeogenous rhizomes, aerial rhizomes, specialized procumbent stolon-like biennial shoots as well as by tubers. The ability to form vegetative diaspores is determined by the microstructure of metamorphosed organs of reproduction, i.e. marked parenchyma development, extensive supply of ergastic substances (starch, aleurone), poor lignification and lack of supporting tissues and cork (excluding Ehretia, Mertensia); the protective function is performed by metacutinized peripheral bark layers and wide dead leaf bases. Specialized organs of vegetative propagation are also characterized by accelerated differentiation and development, short-term activity of the vascular cambium, their fast renewal and additional increased ability to produce adventitious buds and roots. The revealed diversity of vegetative dispersal and propagation ways facilitated the successful expansion of Boraginaceae into various ecological niches in the vegetation of subtropical and tropical areas.
... For disturbance regimes, the range of habitats in which root-sprouting species occur is wider than that of rhizomatous species (Klimeš and Klimešová, 1999). Some of the most invasive weeds belong to root resprouters (Rauh, 1937). In addition, herbaceous plants cope with recurrent graze disturbance by resprouting from rhizomes . ...
... 1), later Director of the Botanical Garden and Botanical Museum Berlin. In March 1937 he finished his studies with a thesis on hypocotyle-and root-offsprings (Rauh 1937) and qualified as a grammar school teacher in June 1937, which gave him the chance to earn some money. He continued his scientific work with research on cushion plants, a result of his passion for alpine flora. ...
Werner Rauh (1913–2000), one of the most famous German Botanists of the 20th century, was a member of IOS from 1959 until his death, Vice-President 1976–1982, President 1982–1984 and first recipient of the Cactus d’Or (1978). His enormous scientific assets, archived at Heidelberg and Bonn, are being opened up systematically by the ‘Werner Rauh Heritage Project’ (Koch et al. 2013), generously funded by the Klaus Tschira Foundation. On the occasion of the 10th IOS Intercongress Meeting at Berlin this brief presentation of recent results of research on his biography was given, a few days before the centenary of Rauh’s birth.
... A morphologically similar architecture is represented in the fungus-colonized mycorrhizome* of Neottia nidus-avis Rich. (Orchidaceae), that is provided with densely clustered exogenous roots (BERNARD 1902; RAUH 1937 ). In V. flavescens even the term 'root' has to be used with reservation, as through the rhizoferous axis. ...
Afrothismia saingei, a new species of Burmanniaceae (tribe Thismieae) from Mt. Kupe in South-West Cameroon is described and illustrated. It differs from the other species of the genus Afrothismia by the size of its flower, the long, distinctly heteromorphic tepals with fringed basal extensions, the dorsal invagination of the perianth tube and the unique shape of the internal flange.
... After attending gram- mar school in Bitterfeld, Rauh studied Botany, Zoology, Chemistry and Geology at the universities of Leipzig, Innsbruck and Halle/Saale, respectively. In 1937, he completed his studies with a doctoral thesis (Rauh 1937). In 1939, he habilitated with the manuscript ''U ¨ ber den polsterförmigen Wuchs'' (Rauh 1939) and accepted a position as a university assistant with Prof. A. Seybold at the former Institute for Botany at Heidelberg University. ...
Prof. Werner Rauh (1913–2000) was the director at Heidelberg Botanical Garden and Herbarium for several decades and until his retirement in 1994, he undertook more than 36 expeditions, mainly to South and Central America as well as to southern Africa and in particular to Madagascar. From these journeys, he brought back innumerable plants to the Botanical Garden Heidelberg, especially succulents, bromeliads and orchids, which are a valuable part of today’s living collection and of the Herbarium. During his expeditions, he wrote more than 90 booklets with detailed information not only about the plants collected, but also about the vegetation and geology of the regions he visited. The heart of the presented Werner Rauh Heritage project is a relational database to store the heterogeneous information found in these field books, as well as to link the information to actual taxonomy and to the garden’s existing database, the living collection and numerous plant type material. A number of powerful tools are being developed to enable researchers to search the database for cross-linked information including Rauh’s original field numbers and the place of collection. The central part of the Werner Rauh Heritage Project database is a look-up table with the geo-referenced itineraries of Werner Rauh’s journeys and another table with all taxa entries listed in any field book. Tables with synonyms, basionyms and protologue data are included as well as numerous images and links to other taxonomic databases such as IPNI and TROPICOS.
... The specific capacity of plants to grow and reproduce clonally has had a continuous attraction for botanists. Detailed accounts of the morphology and anatomy of clonal plants exist from the middle of last century onwards (Irmisch 1850;Velenovsky 1907Velenovsky -1913Goebel 1928Goebel -1933Rauh 1937;Troll 1937Troll -1942Salisbury 1942;Leakey 1981). More recently research has focused on the functionality of this fascinating complex of traits in adapting clonal plants to their environment (Harper 1977;Jackson et al. 1985; van Groenendael & de Kroon 1990;Callaghan et al. 1992;Soukupova et al. 1994; de Kroon & Oborny & Podani 1996). ...
Somatic embryogenesis is a phylogenetically ancient trait that allows
sessile plants to grow in a modular fashion and to respond plastically
to different environmental cues. It facilitates damage repair and
permits clonal growth, the capacity to produce potentially independent
but genetically identical offspring. Clonal growth is observed to
originate from both the shoot or the root part of the plant body and it
has been assigned various ecological functions such as reproduction,
exploitation and persistence. These functions are rooted in two basic
morphological characteristics of clonal growth: the longevity and the
length of the connection between clonal parts. Clonality, although an
ancient trait, shows a polyphyletic distribution among plant taxa with a
strong representation especially among monocots. Phylogenetically
controlled comparisons show that clonality is more common among species
that occur in cold or nutrient-poor habitats and under poor light
conditions. The frequent occurrence of clonals among aquatic species is
confounded by the fact that many aquatics are monocots. This however
does not necessarily preclude a functional ecological explanation. It is
further shown that longevity and length of connection covary negatively,
yielding two distinct clonal growth strategies (fragmenting versus
compact, persistent clones) with a preference for the more common
habitat trait combinations: nutrient-rich, shaded and/or wet versus
nutrient-poor, open and/or dry, respectively.
Premise:
Root-sprouting (RS) is an evolutionary independent way how a plant attains its architecture, alternative to axillary stem branching. RS plants are better adapted to disturbance than non-RS plants, and the vigour of RS is frequently boosted by biomass removal. Nevertheless, RS plants are rarer than plants that are not capable of RS - possibly because they must overcome developmental barriers such as intrinsic phytohormonal balance or because RS ability is conditioned by injury to the plant body. The objective of this study was to identify what is behind the ability of RS: phytohormones or injury?
Methods:
In a greenhouse experiment, growth parameters, root respiration and phytohormones were analysed in two closely related clonal herbs that differ in RS ability (spontaneously RS Inula britannica and rhizomatous non-RS I. salicina) either exposed to severe biomass removal or not.
Results:
We confirmed RS ability in the previously reported RS species I. britannica; however, RS ability was not boosted by injury. While root respiration did not differ between the two species and decreased continuously with time irrespectively of injury, phytohormone profiles differed significantly. In RS species, the auxins-to-cytokinins ratio was low and injury further decreased it.
Conclusions:
Our study represents the first attempt to test drivers behind different plant growth forms and suggests that intrinsic phytohormone regulation, especially the auxins-to-cytokinins ratio, might be behind RS ability. Injury - causing phytohormonal imbalance - seems to be less important in spontaneously RS species than it has been expected for RS species in general. This article is protected by copyright. All rights reserved.
One of the strategies employed by plants to counter weed control is to survive and resprout from belowground organs (the tolerance strategy). This strategy is possible because of the existence of specialized organs like rhizomes, roots with adventitious buds, or tubers. These organs have multiple functions: clonal growth, resprouting, and vegetative propagation. Such functions are facilitated by the ability to store carbohydrates and reserve meristems in order to produce new aboveground shoots and new fine roots after seasonal dormancy or disturbance. Weeds usually combine the tolerance strategy with other strategies, namely with avoidance and resistance strategies, typical for short‐lived weeds dependent on seed reproduction. Which strategy becomes the most important depends on weed control practices, plant traits, and environmental conditions. Weeding practices can be characterized as a type of disturbance regime with specific timing, predictability, severity, and frequency. Plant traits contributing to tolerance strategies also include the quantity of stored carbohydrates and size of the budbank. Regeneration after weeding, however, may also be affected by other factors like plant ontogeny or soil nitrogen availability. Weeding represents a strong selective pressure leading to selection of the best adapted genotypes. While low intensity mechanical weeding selects for tolerance strategies, i.e., weeds resprouting from specialized organs, high intensity mechanical weeding selects for avoidance strategies, i.e. weeds regenerating from seeds. Finally, the use of herbicides favors short‐lived weeds producing easily dispersed seeds that allow for the spread of resistant genotypes.
The potential of several common weed species to produce adventitious shoots when the plants were excised approximately 1.0 cm below the cotyledonary node at the cotyledon growth stage and at the four true-leaf stage is reported. Indian jointvetch ( Aeschynomene indica L. ♯ ³ AESIN), northern jointvetch [ Aeschynomene virginica (L.) B.S.P. ♯ AESVI], and wild poinsettia ( Euphorbia heterophylla L. ♯ EPHHL) produced adventitious shoots at both growth stages after shoot excision. Adventitious and vegetative regeneration of wild poinsettia damaged by herbicides was similar to that from decapitation.
Growth forms of 12 european Trifolium species were studied. Observations were made in the field and in greenhouses. Additional studies were carried out on herbarium material. Starting from the growth type of a perennial semi-rosette plant with an elongated main axis and orthotropic basal shoots, in the sense of Troll, each terminating in a homothetic double raceme (T. hybridum L.), four main trends could be seen:
Unter dem Erstarkungswachstum verstehen wir die periodische Zu- und Abnahme der Achsendicke im Verlauf der Längenentwicklung des Achsenkörpers. Es ist vor allem von Monokotylen und Pteridophyten bekannt, über die man die zusammenfassende Darstellung bei Troll (1937, S. 208) vergleiche.
Ähnlich wie im Bereich der niederen Pflanzen kann auch bei Spermatophyten der vegetativen Fortpflanzung eine bedeutende Rolle für die Erhaltung und Verbreitung der Arten zukommen. Dies gilt keineswegs allein für zahlreiche in Kultur befindliche Gewächse, es trifft ebenso für eine Fülle von Wildpflanzen zu. von denen manche sogar vorwiegend oder gar ausschließlich auf diese Form der Reproduktion angewiesen sind. Es sei nur an solche diöcischen Arten erinnert,von denen das eine Geschlecht in einem bestimmten Areal fehlt, wie Elodea canadensis, die in Europa nur durch weibliche Exemplare vertreten ist, oder wie Hydrilla verticillata, die sich ähnlich verhält (vgl. Möbius 1940, S. 29). Auch von Stratiotes aloides sind die Geschlechter oft auf verschiedene Areale verteilt (Glück 1906. S. 93). Wo selbst sterile Individuen nur vereinzelt vorkommen,stellt die vegetative Reproduktion ebenfalls das einzige Mittel zur Klonbildung dar, wie es Lövkvist (1956, S.41) etwa für arktische Sippen von Cardamine pratensis ausführt. In den Heiden und Mooren Lapplands konnten zahlreiche Arten allein durch vegetative Ausbreitung ein größeres Areal erobern, besonders solche, die aus benachbarten Waldgebieten in die klimatisch ungünstigerenFjelde vordrangen, wo sie nicht mehr zum Samenansatz gelangen (Söyrinki 1938, S. 208ff.). Ähnliches gilt für Acorus calamus in Mittel- und Nordeuiopa, der hier keine keimfähigen Samen zu erzeugen scheint. In tropischenGebieten können z.B. die selten blühenden Bambuseen binnen kurzer Zeit große Flächen besiedeln, allein durch ihre vegetative Ausbreitung (vgl. Abb. 1).
Im Wesen der Speicherung liegt es, daß Stoffe, die im Überschuß gebildet werden, als Vorrats- bzw. Reservesubstanzen zur Ablagerung gelangen, um bei Bedarf wieder mobilisiert zu werden. Solche Prozesse können sich im täglichen Rhythmus schon in jeder assimilierenden Einzelzelle abspielen. Im allgemeinen aber verstehen wir unter Speicherung im engeren Sinne die Anreicherung von Stoffen in wenig reaktionsfähiger Form an meist sekundärer Lagerstätte, wo sie eine längere Zeit verharren und erst nach dieser Ruheperiode wieder in den Stoffwechsel einbezogen werden. Die Tatsache, daß diese Mobilisierung in engstem Zusammenhang mit der Reproduktion bzw. Weiterentwicklung der betreffenden Organismen oder Teilen von ihnen steht, wurde einleitend im vorhergehenden Beitrag1 schon erwähnt, bedarf hier aber noch einer näheren Erläuterung.
Anm.: Die zahlreichen f?r den Entwurf der Karten verwendeten Titel (Floren, Teilkarten, Monographien) k?nnen in der Literatur-?bersicht nicht aufgef?hrt werden.
Unter phagotropher Ernährung versteht man eine Form der Nahrungsaufnahme, bei der feste Teilchen ins Innere von Zellen geraten und durch enzymatischen Abbau ihrer verdaulichen Bestandteile beraubt werden.
The study presents new data about the developmental morphology of vegetative and floral structures of Zeylanidium olivaceum (Gard.) Engler, a crustose representative of Podostemaceae. The renewed debated nature of the crust (root versus thallus) is clarified. The root nature is evidenced by (1) the existence of a fringe of root cap cells, (2) the presence of an inner meristem, responsible both for the growth of the root and the root cap cells, (3) lack of leaves (aphylly), and (4) the endogenous development of secondary (root-borne) shoots. Secondary shoots occur in the form of floriferous and vegetative shoots. They all grow plagiotropously and are orientated towards the respective front of the growing crustose root. The axes are zygomorphic, with the leaves being unilateral at their bases and asymmetrical in shape. The floriferous shoots are distichously foliated; but instead showing a 180°phyllotaxis, the leaves arise in a divergence angle of about 25°to 30°. The leaves, therefore, form two nearly parallel rows on the upper side of the plagiotropous shoot axis. The axes of the vegetative shoots are inconspicuous, remain within the crustose root and are more or less confined to a tiny shoot apex, from which the leaves develop. The leaves are filiform, and only they become visible above the surface of the crust. They are basally fused to the crust as well as to each other, resulting in a short compact zone at the basis of the tuft. The phyllotactic pattern is the same as in the floriferous shoots. Secondary (floriferous and vegetative) shoots as well as the upright growing primary shoot thus differ markedly from each other (shoot polymorphism). The syncarpous gynoecium of the flower consists of two carpels which are equal in size and not unequal as described in the literature. But they are positioned at different levels on the axis, being seemingly shifted against each other.
We studied the growth habit and root anatomy on two species of the Macroptilium genera, Fabaceae. These species, potential forages, are native to the Northwest Provinces in Argentina. The aims of this paper were to determine the survival capacity of the study species relating its growth habit and persistence with morphological and anatomical features. Root samples were collected and cut using either a microtome or by hand, at varying distances from the root tip. Cuts were examined under a light microscope, and with scanning electron microscopy (SEM) using staining techniques. Macroptilium bracteatum and M. erythroloma are perennial herbs. Aerial parts die during winter, and sprouting occurs in spring from the innovation area, throughout sub-superficial buds. In addition, M. bracteatum and M. erythroloma develop root succulence as a strategy of persistence. Besides, M. bracteatum presents endogenous root buds arising from one-year-old roots with secondary growth. These results indicate that both Macroptilium bracteatum and M. erythroloma have good potential as forage species.
Werner Rauh (1913–2000) war einer der bedeutendsten deutschen Feldbotaniker und Pflanzenjäger im 20. Jahrhundert. Sein Interesse galt zunächst der Archäologie, dennoch entschied er sich Botanik, Zoologie, Chemie und Geologie zu studieren. Nach der Dissertation in Halle (Saale) und der Habilitation in Heidelberg nahm Rauh seine Lehrtätigkeit an der Universität Heidelberg auf, wo er bis zu seiner Emeritierung 1982 und darüber hinaus lehrte. Dabei war die Morphologie, d.h. die Lehre vom Bau der Pflanzen, sein erster Schwerpunkt. Mindestens 36 große Expeditionen führten ihn u.a. nach Peru und Madagaskar, aber auch in zahlreiche andere Länder der Alten und Neuen Welt. Im „Werner Rauh Heritage
Project“ werden seit 2009 die Feldbücher von Werner Rauh mit seinen Aufsammlungen lebender und herbarisierter Pflanzen aufgearbeitet, die heute den Grundstock von Botanischem Garten und Herbarium Heidelberg (HEID) bilden.
Zusammenfassung Primär- und Sekundärhaustorien von 15 Arten des Wurzelparasiten Orobanche wurden morphologisch und anatomisch untersucht. In der Struktur des intrusiven Organs sind Unterschiede zwischen den Arten zu erkennen, und zwar in der Form, daß das intrusive Organ entweder geschlossen oder fingerförmig in das Wirtsgewebe eindringt. Im Angriffsbereich des intrusiven Organs vermehren sich die Rindenzellen und die Xylemelemente der Wirtswurzel. Das Sekundärhaustorium ist halbkugelig, es wird nach der Kontaktaufnahme mit der Wirtswurzel zu einem zylindrischen Gebilde gestaucht. Der Durchmesser des Sekundärhaustoriums liegt zwischen 0,5 bis 1,7 mm; die Farbe variiert zwischen weißlichgelb bis rötlichbraun. Sowohl die Entwicklung des Haustoriums als auch die Differenzierung zum Haustorialkern und zur Xylembrücke ist anfangs bei allen von uns untersuchten Arten gleich. Sobald das intrusive Organ (Endophyt) die Wirtsleitelemente erreicht hat, ergeben sich jedoch Unterschiede zwischen Orobanche ramosa und den anderen Arten.
This paper summarizes and elaborates upon previously published investigations of the comparative morphology of vegetative features of Tristicha trifaria (Bory ex Willd.) Spreng., Indotristicha ramosissima (Wight) van Royen and Dalzellia ceylanica (Gard.) Wight (Podostemaceae, Tristichoideae) (Jäger-Zürn, 1970, 1992, 1995). The architecture of these taxa can be traced to common developmental patterns in angiosperms. Alterations of typical structures within the “principles of variable proportions” contribute to their eccentric appearance.
In root-layers of Symphytum officinale development as well as storage and consumption of carbohydrates is determined by day length, in a manner similar to that in plants developed from seeds. Root-layers differ in the following points:1.
Flowers are always formed after 16–19 leaves, even at a day length of 12 hours at which 26–29 leaves usually appear before flowers are formed.
2.
In cultures kept at temperatures of at least +10° C fructosans are stored in the young shoot-born roots, while the amount of fructosans is reduced in the buds, in the subterraneous shoot parts and in the old root pieces.
The old root piece remains a living part in the root-system of the layer and takes part in the renewed storage of starch just like the primary root of plants developed from seeds.
The development of a seedling into an adult plant comprises various underground processes. Time-lapse photography (TLP) makes them visible. This is documented for Potentilla inclinata (Rosaceae) and Inula ensifolia (Asteraceae).After germination, P. inclinata develops a taproot system. Contraction phenomena pull the basal part of the shoot at least 10mm into the soil. Later, several adventitious roots are generated, and thus the root system changes to a fibrous one. This is followed by cloning without separation of the ramets.Seedlings of I. ensifolia develop a weak primary root. At an early stage, adventitious roots are formed at the leaf rosette. This fibrous root system exerts a strong pulling effect on the shoot. After one vegetation period the basis of the rosette is approx. 30mm under the soil surface. Cloning includes the formation of many new horizontal shoots, which conquer new sites.These two examples show three functional steps common in the developmental progress of subterranean systems: (I) establishment of the seedling, (II) innovation and survival of the young plant, and (III) reiteration (cloning and dispersal). However, to accomplish these basic development steps the diversity of subterranean systems is enhanced by different organographical components.Furthermore, the development of subterranean systems is a dynamic process consisting of two kinetic processes: the vertical movement during seedling establishment, which brings the innovation buds to a safe soil position, and the horizontal movement during dispersal, which conquers new sites.
Zusammenfassung 1.Sowohl die Versuche mitVicia Faba als auch die mitLinum usitatissimum haben erkennen lassen, daß trotz aller Unspezifität ihrer Wirkungsweise die ausgesprochenen Wuchsstoffe Heteroauxin und 2,4-D in Konzentrationen des Hemmbereiches und die eigentlichen Hemmstoffe Zimtsäure und Cumarin sich nicht nur quantitativ sondern auch qualitativ hinsichtlich ihrer Wirkung auf Kotyledonar- und Hypokotylknospen unterscheiden. Nur die Wuchsstoffe sind sowohl zur völligen Unterdrückung als auch zur Förderung der Knospen befähigt. Die Hemmstoffe wirken in physiologischen Konzentrationen nur schwach oder mäßig hemmend auf die Entwicklung der Knospen.2.\-Indolylessigsäure wird in ihrer Aktivität von 2,4-Dichlorphenoxyessigsäure (2,4-D) übertroffen.3.Es wird wahrscheinlich gemacht, daß die Hypokotylknospen der Keimlinge vonLinum usitatissimum physiologisch vorgebildet sind.
In the parasiticScrophulariaceae andOrobanchaceae, two types of contact organs exist: secondary and primary haustoria. Secondary haustoria are lateral organs, developing in large numbers and only when the seedling is fully established. In contrast, a primary haustorium represents the first developmental stage of the seedling itself. In the root system of the parasiticLesquereuxia syriaca (=Siphonostegia syriaca) there are only secondary haustoria, but a few of them apparently develop in a terminal position. This is achieved by transferring the haustorial initiation region closer to the root apex. One can interpret this as a transformation of the apical meristem into a meristematic haustorial tissue. On the condition that an extreme shortening (abbrevation) of the primary root could happen, we discuss the transformation of the terminal secondary into a primary haustorium.
The investigations of the authors were made in the Buda Hills, in a stand of calciphilous oak forest (Orno‐Quercetum), a Submediterranean xerothermic forest association frequent in the Transdanubian part of the Hungarian Central Range. Subdividing the 1024 m ² sample plot into 64 portions, the cover values of the dominant‐ and frequent species were noted; in the same system holes were dug in the ground and 7 physical soil factors studied in all of the soil layers. Considering these factors (together with tree‐ and shrub cover) as independent ones affecting the species, correlations were calculated between them and the several species. Diverging from preceding studies, not merely first grade (linear) but also quadratic (parabolic), square root, exponential, and logarithmic models were also applied.
Some significant correlations may be pointed out among the results. The connection between Vicia sparsiflora and pH is considerable and demonstrable by several methods: related probably to the pH requirement of nitrogen‐fixing bacteria symbiotic with the plant. In the case of Lithospermum purpureo‐coeruleum , it is not the pH but the nutrient demand wich appears to be the regulating factors: as shown by its close correlation with humus and potassium. On the other hand, the close correlation between Quercus pubescens and humus may result from the inverse relation between humus and soil depth, indicating the significance of topographic effects. Humus plays a role in the appearance of Oryzopsis virescens but also in that of Euphorbia cyparissias ; this latter is decisively influenced also by light conditions.
Results can, however, be evaluated also methodically. Accordingly, the linear model presents in some cases a good description of the interrelationships, whereas the parabolic approach is better in a great number of other cases; this indicates that in these ones not all regions of the connection is of the same character and that in our ecosystem one has to consider, in several cases, minimum and maximum effects and the subsequent alteration of the direction of relationship. As for the other types of connection, one has to take into account the exponential in some cases.
Ausgehend von der Forderung nach einer umfassenden, neben Morphologie und Anatomie auch Wuchsrhythmik und Standortbindung berücksichtigenden Wuchsformenanalyse werden einige Wuchsformenreihen mediterran-mitteleuropäischer Angiospermen-Taxa behandelt. Bei Carlina, Scabiosa und Digitalis werden die Beziehungen von kanarischen oder südmediterranen Kandelabersträuchern zu submediterran-mitteleuropäischen Pleiokormstauden einerseits und zu Annuellen andererseits dargestellt. Besondere Beachtung findet dabei die Differenzierung des Pleiokorm (Scabiosa, Digitalis) und der Radikation (Carlina). Die verschiedene Ausdehnung des verholzten Teiles innerhalb der Sproßsysteme bei mediterranen und submediterranen Sträuchern, Halb- und Zwergsträuchern sowie bei mitteleuropäischen mehr oder weniger krautigen und geophytischen Vertretern wird am Beispiel von Arten der Gattungen Thymus und Teucrium erörtert. Außerdem werden die Wuchsformen einiger geophytischer Stauden der mitteleuropäischen Waldvegetation aus der Gattung Euphorbia mit den Wuchsformen ihrer mediterranen Verwandten verglichen.
A concept for a primitive angiospermous branch system is given in order to have a starting point for the derivation of the diverse and highly differentiated branch systems observed in contemporary angiosperms. Hitherto Troll's (1964, 1969) comparative study of the synflorescences in this plant group — developed out predominantly on herbaceous plants — was the most comprehensive and sophisticated treatment dealing with branch systems. Unfortunately, the work on tropical tree architecture by Hallé et al. (1978) has no reference to the classical studies of Troll and his pupils. Thus Müller-Doblies and Weberling (1984) emphasized the high degree of terminological incompatibility between the two works. Angiosperms are seen as a monophyletic plant division. Consequently, the branch system of the first primitive angiosperms must be the starting point in the evolution of the abundant diversity of branch systems and growth forms of modern angiosperms. If it is accepted that primitive angiospermous shoots were terminated by a large flower, one may assume, that the reproductive end of the shoot was enriched by paracladia early in evolution, thereby developing a terminal inflorescence instead of a single flower. Thus the primitive shoot unit was divided into a basal vegetative region — the trophotagma, branching retardively — and the reproductive terminal region, the anthotagma, branching simultaneously. It is demonstrated through a selection of different examples, that the construction of such a system possesses the options for several modifications, enabling the evolution of the abundant diversity of branch systems which characterizes contemporary angiosperms.
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