Search

One of the major challenges of ecologists and biogeographers is to understand how species are globally distributed. Two of the most well-studied large-scale patterns in species distributions are the Rapoport's rule and the Latitudinal Diversity Gradient (LDG). We aimed to address whether Neotropical odonates follow the Rapoport's rule and if there is a latitudinal gradient in species diversity. A total of 1076 records for 190 species, covering a large area from southeastern to the northern regions of Brazil that extends from 23°S (Cerrado) to 3°N (Amazon Rainforest). Generalized Linear Models were used to address whether Neotropical odonates follow the Rapoport's rule, and if there is a latitudinal gradient in species diversity, based on our predictions. We found a Rapoport effect in the Amazon biome and an inverse Rapoport effect in the Amazon-Cerrado Transition Forest and Cerrado biome. Regarding LDG, we found no significant effect of latitude on species richness patterns when we considered all the species, and a significant relationship between species richness and latitude for zygopterans. The spatial patterns of odonates geographic distribution may be an outcome of geographical barriers, for instance, the continental geometry of South America, which is broader in the north and limits geographical expansion towards the south. Furthermore, species ecophysiological mechanisms may also hamper their expansion and drive the pattern observed in our study, mainly because of evolutionary thermoregulatory adaptations that each taxon exhibits along its environmental gradient. [ABSTRACT FROM AUTHOR]

The chief subject of this brief overview is a vetch species, once distinguished as Vicia calcarata Desf. and currently regarded as V. monantha Retz. subsp. triflora (Ten.) B. L. Burtt & P. Lewis, but we prefer to distinguish this taxon at species level as Vicia calcarata. It is a volunteer plant occurring regularly on ruderal sites in the local floras of the coastal and maritime areas of the Mediterranean Basin, and sporadically happens to be cultivated in fields. It has a more robust growth habit than V. monantha subsp. monantha, with usually three flowers per peduncle and larger seeds, rather constant morphological traits. In situ and on-farm observations on V. calcarata are scarce, relating mostly to the southern mainland of Italy and its islands, Spain, North Africa and Syria, where it is found in forests, grasslands, wheat fields, ruderal soils and along roadsides. On a global scale, there are 91 accessions of V. calcarata in six ex situ genebank collections in Alcalá de Henares, Bari, Beirut, Gatersleben, Sadovo and St. Petersburg. In a series of ex situ field trials in Novi Sad, twelve accessions of V. calcarata produced average yields of 6.3 t ha−1 of forage dry matter and 1100 kg ha−1 of seed. There are promising perspectives for developing cultivars of V. calcarata, since the available divergence offers a solid basis for crop improvement. After a long fall, a novel rise of V. calcarata is yet to come. [ABSTRACT FROM AUTHOR]

The terrestrially hibernating wood frog (Rana sylvatica) is well-known for its iconic freeze tolerance, an overwintering adaptation that has received considerable investigation over the past 35 years. Virtually, all of this research has concerned frogs indigenous to the temperate regions of its broad range within North America. However, recent investigations have shown that frogs of subarctic populations are extremely cold hardy, being capable of surviving freezing for longer periods and at much lower temperatures as compared to conspecifics from temperate regions. Their exceptional freeze tolerance is partly supported by an enhanced cryoprotectant system that uses very high levels of urea and glucose to limit ice formation, regulate metabolism, and protect macromolecules and cellular structures from freezing/thawing stresses. In the weeks before they begin hibernating, northern frogs undertake radical physiological transitions, such as depletion of fat stores and catabolism of muscle protein, that prime the cryoprotectant system by accruing urea and stockpiling glycogen from which glucose is mobilized during freezing. Concentrations of cryoprotectants ultimately achieved in Alaskan frogs when freezing occurs vary among tissues but generally are higher than those of frogs inhabiting milder climates. This review summarizes the molecular, biochemical, and physiological adaptations permitting this northern phenotype to survive the long and harsh winters of the region. [ABSTRACT FROM AUTHOR]

Lathyrus cicera L. is one of the oldest cultivated plants in the world, originating in the Mediterranean centre of diversity. Together with its close relative, L. sativus, it is most likely the first crop domesticated in Europe, namely in the Iberian Peninsula and southern France. Today, L. cicera is sharing the destiny of numerous, legume, cereal and other once widely grown species, becoming largely neglected and underutilised, extremely sporadically cultivated for food and feed, with almost no breeding strategies and often escaping from local agricultures into neighbouring wild flora. Still, numerous in situ and on-farm investigations confirm that L. cicera has a remarkable infraspecific diversity, which, along with the existing ex situ collections across the world, proves as a solid basis for its improvement and reintroduction. There are sufficient resources for both developing new advanced cultivars and maintaining the locally cultivated and maintained landraces. Lathyrus cicera has a considerable potential for producing more than 8 t ha−1 of forage dry matter (hay) and around 3.6 t ha−1 of dry grain, with a dry matter crude protein content in both surpassing 250 g kg−1, for a substantial reduction of the content of neurotoxin oxalyldiaminopropionic acid (ODAP), an enhanced resistance to various stress factors, such as drought, low temperatures, powdery mildew, pseudomonas, rust or crenate broomrape, for a safe inclusion into human diets and animal feeding and for various environment-friendly uses. Equally important for reintroducing L. cicera is the promotion of the currently rather rare regional folk customs and gastronomic festivals devoted to this cultivated plant, such as the Sagra della maracucciata, regularly celebrating maracuoccio, as it is called in the Chilentan dialect, in the Camerotan hamlet of Lentiscosa, in southwest Italy, with thousands of visitors from elsewhere and for more than a decade. [ABSTRACT FROM AUTHOR]

Genetic variability was studied in 78 populations of locally collected Vicia L. taxa for seed albumins, globulins and prolamins patterns by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) along with an ecogeographic characterization of sites investigated. 131, 119 and 98 bands were respectively used for albumin, globulin and prolamin cluster analysis. Dendrograms based on the Jaccard index and the UPGMA method were generated and the degree of genetic diversity between and within taxa was evaluated. Five clusters were generated from albumins, six from globulins and four from prolamins patterns. The results reflect the great diversity of storage proteins and a high correlation was obtained between the three studied fractions. Several accessions present specific bands which could be used as a discriminatory marker both on intra and interspecific levels. No clear relationships were seen between the groups according to their geographical origin. Data obtained from ecogeographic investigation can be used for future collecting missions. [ABSTRACT FROM AUTHOR]

Vicia sativa s.l. is one of the most commonly grown forage crop in Mediterranean regions. It is widely distributed and presents at the same time the largest overlaps and the most difficult taxonomic problems. The present study is an attempt to characterize the diversity and the taxonomic relationships among the members of a collection of 34 V. sativa s.l. from a variety of geographical sources of North Algeria with the aim to improve their conservation and management along with a synthesis of the results obtained by previous researchers. Four taxa ( obovata, cordata, consobrina and angustifolia) were analysed using 5 ecogeographic parameters and 78 morphological characters coded as multistate. The results reflect the great diversity of vetches and subspecies were not clearly recognizable from their plant morphology and ecogeography. Cluster analysis does not have provided clear separation among accessions. 11 morphological characters were excluded as they are homologous between all accessions. Important variation in standard colour, leaflets pairs per leaf, tendril length, hilum length and legume suture curvature was found in most accessions of the collection. Even for the characters that contribute the most to the separation of the accessions, the range of variation does show overlap between the subspecies. The study has drawn accessions from a wider geographical range and a distribution map of each taxa was produced. The information obtained can be used as a guide for future collecting missions. Variation in morphological characters appeared to be related to the site from which the accession was collected with 44.89 %. [ABSTRACT FROM AUTHOR]

Beautiful Vavilovia [ Vavilovia formosa (Stev.) Fed.] is a perennial legume of great importance for the evolution and taxonomy of the tribe Fabeae Rchb. The abundant data on its collection sites on the Caucasus Mountains, made during the past two centuries, were collated and analysed. The studied area covers the mountain ranges of both the Greater and Lesser Caucasus in Russian Federation, Georgia, Armenia and Azerbaijan, except the ranges in north-eastern and eastern Turkey and north-western Iran. The presented data are the results of an analysis of the herbarium collections of various institutions and available literature resources, providing novel information about 110 collection points. The analysed data allowed to specify the borders of the area in the region, as well as describe the features of the high-altitude distribution of V. formosa within the studied area, revealing the lower and upper altitude ranges as between 2021 and 3500 m above sea level. The results also indicate a reduction of the number of its populations, as well as the necessity and urgency of monitoring and protecting all the known locations of this highly endangered species. [ABSTRACT FROM AUTHOR]

Pea ( Pisum sativum L.) is grown widely throughout China and has undergone natural selection throughout its agricultural range over 2,000 years. Here we characterize collection site habitats to develop an understanding of the key selection pressures likely to be imposed by each environment to facilitate the investigation of specific adaptation. We characterized 240 collection sites of 529 pea landraces, across 25 provinces and 3 municipalities of China comprising the main pea cropping regions for climatic variables. Multivariate analyses showed that collection sites tended to cluster along geographic and abiotic stress clines. Spring sown sites and winter sown sites were clearly separated into 6 and 7 habitat type clusters respectively. In addition, regions which experience extreme abiotic stresses of frost, drought and high temperature in the reproductive period for pea landraces, were identified as targets for germplasm to be tested for respective tolerances to these stresses. [ABSTRACT FROM AUTHOR]

The debate surrounding Bergmann's rule, in which the body size of animals is predicted to be larger in cooler environments, is still open concerning ectotherms. Our goal was to test this rule in the broadest ranging amphibian species Salamandrella keyserlingii. We determined age and body size in a cooler region (Darhadyn, Mongolia: mean yearly air temperature = -8.31 °C) using skeletochronology, and compared their differences in altitude, latitude, and temperature with those of a warmer area (Kushiro, Japan: 7.98 °C). In Darhadyn, both sexes reached sexual maturity at 5-6 years of age (growth coefficient: male = 0.585, female = 0.266), 2-3 years later than those in Kushiro (male = 1.341, female = 1.129). Mean body size was smaller in Darhadyn (53.08 mm) than in Kushiro (57.63 mm) for males despite their constant metamorphic size around 30 mm. We also analyzed data available from published studies for 27 populations within the geographic range of this species from 43 to 69°N across a 2,900-km long latitudinal gradient. The analysis indicated an intraspecific tendency to decrease body size with increased latitude from 43 to 57°N, to increase size from 57 to 69°N, and to decrease body size with decreased temperature from 8 to -7 °C and increase size from -7 to -15 °C. This pattern does not follow the intraspecific extension of Bergmann's rule and may follow the converse of Terentjev's optimum rule-a rule formulated to be an inverted-U shaped curve between increased latitude (or decreased temperature) and increased body size. [ABSTRACT FROM AUTHOR]

Quantitative evaluation of phytochemical diversity in Adhatoda vasica Nees populations from five different ecogeographical regions was performed using a highly sensitive, robust and economic high performance thin layer chromatography (HPTLC) procedure. The method was validated for specificity, precision and accuracy as per the guidelines affirmed by International Conference on Harmonization of technical requirements for registration of pharmaceuticals for human use (ICH). The findings support the existence of distinct natural chemotypes within the species. Two out of the five regions had about three times higher mean vasicine content than the remaining three regions. The comparative phytochemical fingerprint profiles were quite similar except for the concentration variation seen for different alkaloids. As the quinazoline alkaloids are the biologically active compounds in A. vasica, the samples that accumulate high levels of alkaloids seem to be promising for further propagation. [ABSTRACT FROM AUTHOR]

Aegilops geniculata Roth is an annual grass relative to cultivated wheats and is widely distributed in North Africa. In order to understand the diversity of this species, 14 populations collected in different bioclimatic areas in northern Algeria were analyzed using morphological and biochemical characters. Principal component analyses (PCA) based on the inflorescence characters and ecological parameters allowed the separation of populations in two mainly bioclimatic clusters characterized by different morphological patterns. Populations originated from humid and sub-humid coastal areas were characterized by vigorous spikes. Samples collected from intermediate and high mountains with humid and semi-arid conditions had long and lanceolate spikes. Individuals with small and narrow spikes were characteristics of steppic highlands in semi-arid conditions and high mountains with humid bioclimate. Individuals were distinguished successively by spike width, spike length, rachis length and awns number. Electrophoretic analyses of high molecular weight glutenin subunits (HMW-GS) based on the phenotypic variability and genetic distances revealed a significant variation within and between populations associated with bioclimatic conditions, in particular winter temperature. Genetic diversity was higher in populations growing under warm bioclimates than in those from cold bioclimates. These results suggest that a part of the variation for HMW glutenin variability is adaptive. [ABSTRACT FROM AUTHOR]

Polymorphism analyses of the hordeins, main storage proteins in barley, were conducted on 35 natural populations of Hordeum murinum s.l. from North Africa; this specific complex includes three subspecies with two ploidy levels: H. murinum subsp. glaucum (2n=2x=14), H. murinum subsp. leporinum and subsp. murinum (2n=4x=28). Twenty of these populations belong to the diploid subsp. glaucum, 14 other tetraploid populations belong to the subsp. leporinum. In addition, six populations of the tetraploid murinum were sampled in France: two along the Mediterranean coast and four in Brittany. The polymorphism observed in the electrophoretic patterns highlights strong correlations between bioclimatic features and di- and tetraploid taxa distribution. Moreover, the variation was not randomly distributed within the different ploidy levels, and is correlated with environmental factors. The ecological differentiation of the two main taxa, H. murinum subsp. leporinum and subsp. glaucum is clearly highlighted. [ABSTRACT FROM AUTHOR]

A collecting mission took place in June and July 1996 to collect legume species from south-west Turkey and western Anatolia. Sites were chosen to maximise the diversity of legumes collected and detailed passport data were recorded at each site. A total of 96 sites were visited, and 1307 accessions collected. In total 23 genera were collected, of which the most frequently seen were Trifolium, Medicago and Vicia. Sites were found to be almost exclusively calcareous with a pH range of 7 to 10, and varied from sea level to 1750m. Many of the Trifolium species are of economic importance for southern Australia and have been shown to display characters such as a high productivity (T. michelianum) and waterlogging tolerance (T. resupinatum and T. tomentosum). The Medicago species were found to prefer well-drained habitats in open areas. Many of these species can tolerate heavy grazing. The two main forage legume genera collected were Lathyrus and Vicia. Both of these occurred on the higher pH soils and were most frequently collected from the lower altitudes. Four species of grain legume were found, Cicer arietinum, Lens culinaris, Pisum sativum and Vicia faba. The material collected during this mission is important in the drive to preserve the legume genetic diversity of Turkey, the species' centre of diversity, for utilisation both within and outside of Turkey. [ABSTRACT FROM AUTHOR]

An ecogeographical analysis of the V. narbonensis complex and V. bithynica was conducted using herbarium specimens and genebank accessions. 956 specimens were included in the study from 26 herbaria, with geographical and ecological data recorded for each specimen. A distribution map of each taxa was produced, and the geographical and ecological preferences of each taxa were analysed and discussed. The taxa with the widest distribution were found to be V. narbonensis, V. bithynica and V. johannis, and the rarest taxa were V. galilaea var. galilaea and V. narbonensis var. aegyptiaca. The complex includes three endemic species; V. hyaeniscyamus, V. kalakhensis and V. eristalioides. The complex as a whole, was most frequently collected from grasslands, as a weed in cultivated fields and in wasteland. It showed a strong preference for calcareous soils. It was found that the quality of the passport data varied widely, but that in general the specimens from more recent collections included more detailed passport data. Herbarium specimens are invaluable in ecogeographic studies as the information obtained can be used as a guide for future collecting missions and in determining areas of importance when collecting material for conservation. Finally as the whole plant is available, the identification of each specimen can be checked. [ABSTRACT FROM AUTHOR]

Due to the considerable annual fluctuations of water level of the Amazonian rivers, their river banks are fringed with periodically flooded forests of vast extension. The biota of these communities are adapted to annual inundations that can last for more than half a year. Water chemistry is most important for the floristic differentiation of these flooded forests. White water rivers, which carry a rich load of suspended material originating from the erosion of the Andes, have a floristic composition related to that of the noninundatable Amazonian forest. Clear water and black water rivers, which originate in the Amazon Basin or its adjacent crystalline shields, are nutrient-poor and more or less acidic; their flora is related to that of peculiar woodland and savannah vegetation on oligotrophic white sand. The distribution patterns of floodplain species of nutrient-poor waters point to a centre of diversity in the Upper Rio Negro region, and another one in the Guayana lowland. These coincide with diversity centres for species of non-flooded habitats. Hence it seems unlikely that species diversity is directly influenced by pluviosity. The flooded forests have developed biotic interactions with the fish fauna of the Amazon Basin, which are vital for their continued existence. It is assumed that the origin of these habitats, their biota and their interactions dates back long into the Tertiary. [ABSTRACT FROM AUTHOR]

Latex is a widespread defence in plants against natural enemies and a literature-based summary of latex-producing angiosperms shows records in 40 families, and more than 20,000 species are estimated to bear laticiferous structures of some kind. This is considerably higher than the usually quoted figure of 12,500 species. There are more tropical than temperate latex-bearing families, both in absolute numbers and proportionally. Proportions of latex-bearing families are similar both in tropical and in more widespread or cosmopolitan families. Significantly more latex-bearing species belong to tropical than either to temperate or to widespread taxa, both in absolute and in relative terms. These differences may be related to the higher diversity of natural enemy species and to higher rates of herbivory in the tropics. [ABSTRACT FROM AUTHOR]