Genetic diversity of Lathyrus sp collected from different geographical regions.

BACKGROUND: The demand for grass peas (Lathyrus sativus L.) had increased as high nutritional safe food, but most of the accessions of South Asia and Africa had low grain harvest. Therefore, this study had been undertaken to collect grass pea germplasm for boosting yields and quality improvement. METHODS AND RESULTS: In this study, 400 accessions of grass pea from different geographical regions had characterized by using 56 Simple Sequences Repeat (SSRs) markers. In total 253 alleles were detected, the maximum and minimum polymorphic information content (PIC) indices were 0.70 and 0.34 found in markers G17922 and G18078, correspondingly. The germplasm was split into two main and one sub-group by cluster assay, by SSR assay, and three populations by model-based population structure analysis (Pop1, Pop2 and admixed). Neighbors joining tree assay showed the tested germplasm highly diverse in structure. Three-dimensional principal components analysis (PCA) and two dimensional principles coordinate analysis (PCoA) exhibited two main and one admixed group (P1, P2 and P1P2). In addition, FST population value of pairwise mean and analysis of molecular variance (AMOVA) showed high population structure across all pairs of populations on an average 0.1710 advocating all population structure categories varied significantly. The average predictable heterozygosity distant was 0.4472-0.4542 in same cluster for the individuals. CONCLUSION: Discovery from this study revealed SSR markers based polymorphic bands showed in the diversified grasspea germplasm which might be utilized as genetic resource of a breeding scheme and prospective uses for mapping analyses of recombinant inbred lines (RIL).

Molecular phylogeny of Lathyrus species: insights from sequence-related amplified polymorphism markers.

Sequence-related amplified polymorphism (SRAP) markers were used to evaluate the intra- and interspecific variation among 40 Lathyrus genotypes (four species) (Fabaceae). Ten SRAP primer combinations resulted in a total of 94 bands, and they exhibited high interspecific variability. The genetic differentiation among Lathyrus, estimated using AMOVA, was highly significant. The results indicated that 58% of the total genetic variation existed among species, and 42% of the differentiation was within species. This was explained by the high level of genome conservation of these species as well as the recent and slow evolution of this genus. These results were confirmed by the topology of the neighbor-joining cladogram and the results of the principal coordinate analysis. Our data support previous results based on seed protein diversity. These results make SRAP markers choice markers for the study of functional polymorphism that is directly related to the transcriptomic data. The SRAP markers used in this study provide an accurate picture of the population structure within Lathyrus germplasm, which is critically important information for the design of genetic diversity and structure analyses. Moreover, further extensive studies are necessary to fully examine other Lathyrus species and tests that adopt the SRAP technique to enrich the Lathyrus library for next-generation sequencing, thus providing a potent protocol for the study of polymorphism.

Karyotype characterization and evolution in South American species of Lathyrus (Notolathyrus, Leguminosae) evidenced by heterochromatin and rDNA mapping.

Notolathyrus is a section of South American endemic species of the genus Lathyrus. The origin, phylogenetic relationship and delimitation of some species are still controversial. The present study provides an exhaustive analysis of the karyotypes of approximately half (10) of the species recognized for section Notolathyrus and four outgroups (sections Lathyrus and Orobus) by cytogenetic mapping of heterochromatic bands and 45S and 5S rDNA loci. The bulk of the parameters analyzed here generated markers to identify most of the chromosomes in the complements of the analyzed species. Chromosome banding showed interspecific variation in the amount and distribution of heterochromatin, and together with the distribution of rDNA loci, allowed the characterization of all the species studied here. Additionally, some of the chromosome parameters described (st chromosomes and the 45S rDNA loci) constitute the first diagnostic characters for the Notolathyrus section. Evolutionary, chromosome data revealed that the South American species are a homogeneous group supporting the monophyly of the section. Variation in the amount of heterochromatin was not directly related to the variation in DNA content of the Notolathyrus species. However, the correlation observed between the amount of heterochromatin and some geographical and bioclimatic variables suggest that the variation in the heterochromatic fraction should have an adaptive value.

Evolution of rbcL among Lathyrus and Kupicha's classification.

Phylogenetic relationships in the Lathyrus genus were examined using cpDNA data, particularly data attributed to the "barcode" rbcL gene to construct a possible evolutionary scenario. Plant barcoding can be used to differentiate between species within a genus and to conserve DNA within the same species. We assessed the phylogeny of 29 species of Lathyrus using maximum parsimony, maximum likelihood and unweighted pair-group method and arithmetic mean. The classifications did not agree with current morphological and basic Lathyrus classification. Lathyrus belinensis is a new species that was not described by Kupicha; according to rbcL analysis, the species belongs in the Lathyrus genus. Additionally, the genus Lathyrus has undergone a rapid population expansion as indicated by neutral selection indices.

Lathyrus diversity: available resources with relevance to crop improvement--L. sativus and L. cicera as case studies.

BACKGROUND: The Lathyrus genus includes 160 species, some of which have economic importance as food, fodder and ornamental crops (mainly L. sativus, L. cicera and L. odoratus, respectively) and are cultivated in >1·5 Mha worldwide. However, in spite of their well-recognized robustness and potential as a source of calories and protein for populations in drought-prone and marginal areas, cultivation is in decline and there is a high risk of genetic erosion. SCOPE: In this review, current and past taxonomic treatments of the Lathyrus genus are assessed and its current status is examined together with future prospects for germplasm conservation, characterization and utilization. A particular emphasis is placed on the importance of diversity analysis for breeding of L. sativus and L. cicera. CONCLUSIONS: Efforts for improvement of L. sativus and L. cicera should concentrate on the development of publicly available joint core collections, and on high-resolution genotyping. This will be critical for permitting decentralized phenotyping. Such a co-ordinated international effort should result in more efficient and faster breeding approaches, which are particularly needed for these neglected, underutilized Lathyrus species.

Systematics, biogeography, and character evolution of the legume tribe Fabeae with special focus on the middle-Atlantic island lineages.

BACKGROUND: Tribe Fabeae comprises about 380 legume species, including some of the most ancient and important crops like lentil, pea, and broad bean. Breeding efforts in legume crops rely on a detailed knowledge of closest wild relatives and geographic origin. Relationships within the tribe, however, are incompletely known and previous molecular results conflicted with the traditional morphology-based classification. Here we analyse the systematics, biogeography, and character evolution in the tribe based on plastid and nuclear DNA sequences. RESULTS: Phylogenetic analyses including c. 70% of the species in the tribe show that the genera Vicia and Lathyrus in their current circumscription are not monophyletic: Pisum and Vavilovia are nested in Lathyrus, the genus Lens is nested in Vicia. A small, well-supported clade including Vicia hirsuta, V. sylvatica, and some Mediterranean endemics, is the sister group to all remaining species in the tribe. Fabeae originated in the East Mediterranean region in the Miocene (23-16 million years ago (Ma)) and spread at least 39 times into Eurasia, seven times to the Americas, twice to tropical Africa and four times to Macaronesia. Broad bean (V. faba) and its sister V. paucijuga originated in Asia and might be sister to V. oroboides. Lentil (Lens culinaris ssp. culinaris) is of Mediterranean origin and together with eight very close relatives forms a clade that is nested in the core Vicia, where it evolved c. 14 Ma. The Pisum clade is nested in Lathyrus in a grade with the Mediterranean L. gloeosperma, L. neurolobus, and L. nissolia. The extinct Azorean endemic V. dennesiana belongs in section Cracca and is nested among Mediterranean species. According to our ancestral character state reconstruction results, ancestors of Fabeae had a basic chromosome number of 2n=14, an annual life form, and evenly hairy, dorsiventrally compressed styles. CONCLUSIONS: Fabeae evolved in the Eastern Mediterranean in the middle Miocene and spread from there across Eurasia, into Tropical Africa, and at least seven times to the Americas. The middle-Atlantic islands were colonized four times but apparently did not serve as stepping-stones for Atlantic crossings. Long-distance dispersal events are relatively common in Fabeae (seven per ten million years). Current generic and infrageneric circumscriptions in Fabeae do not reflect monophyletic groups and should be revised. Suggestions for generic level delimitation are offered.

Barcode High Resolution Melting (Bar-HRM) analysis for detection and quantification of PDO "Fava Santorinis" (Lathyrus clymenum) adulterants.

Legumes considered as one of the most important crops worldwide. Due to high price as a PDO product, commercial products of "Fava Santorinis" are often subjected to adulterations from other legume products coming from other Lathyrus or Vicia and Pisum species. Using plant DNA barcoding regions (trnL and rpoC) coupled with High Resolution Melting (Bar-HRM) we have developed a method allowing us to detect and authenticate PDO "Fava Santorinis". Bar-HRM proved to be a very sensitive tool able to genotype Lathyrus and its closed relative species and to detect admixtures, being sensitive enough to as low as 1:100 of non-"Fava Santorinis" in "Fava Santorinis" commercial products. In conclusion, Bar-HRM analysis can be a faster, with higher resolution and cost effectiveness alternative method to authenticate PDO "Fava Santorinis" and to quantitatively detect adulterations in "Fava Santorinis" with other relative commercial "Fava" food products.

Environmental effect on yield, composition and technological seed traits of some Italian ecotypes of grass pea (Lathyrus sativus L.).

BACKGROUND: Grass pea seeds are a good source of vegetable proteins, but the presence of toxic and antinutritional compounds represents a barrier to their large-scale use as food or animal feed. How much growing location and/or seasonal climate might affect the storage of these factors has been little investigated. RESULTS: Fourteen Italian ecotypes of grass pea were cultivated in two locations in southern Italy characterised by different climatic conditions. The seven ecotypes with the best yields and/or seed quality were investigated for a further two growing seasons. From a statistical point of view the physicochemical and nutritional traits among ecotypes were not the same from one year to the next. Moreover, a significant positive correlation was found between ß-oxalyl-diamino-propionic acid and trypsin inhibitor contents. The lowest levels of both these compounds were associated with the highest amount of rainfall during the plant vegetative cycle. CONCLUSION: Principal component analysis of the data showed that the overall seed composition was affected by the growing location. Consequently, each grass pea genotype should also be carefully investigated in relation to different environments before being considered for release as safe for widespread human or animal consumption.

Analysis of genetic diversity among selected grasspea (Lathyrus sativus L.) genotypes using RAPD markers.

Randomly amplified polymorphic DNA (RAPD) technique was applied to assess the genetic variability among five selected genotypes of grasspea. Out of 30 random decamer primers tested for the present investigation 20 showed reproducible DNA amplification. A total of 257 loci were amplified of which 159 were polymorphic including 57 genotype-specific unique bands. Amplicons had molecular weights ranging from 3.0 kb to 0.1 kb. Majority amplicons were shared by most of the genotypes which indicated a very narrow genetic gap between them. The dendrogram constructed on the basis of RAPD data showed two clusters. The local genotype collected from Nayagarh was grouped along with IC-120451 and IC-120453, sharing a common node at an 82% similarity level. The other genotypes, IC-120478 and IC-120487, were located in the second clade having a common node at 84% similarity level. The investigation showed that though all the genotypes of grasspea were of apparently similar morphology there exists polymorphism at the molecular level, which can be exploited in breeding programmes aimed at crop improvement.

Nodulation and root traits in four grasspea (Lathyrus sativus) ecotypes under root-zone temperatures.

In order to study the effect of four Root-Zone Temperatures (RZT) (5, 10, 15 and 25 degrees C) on nodulation and nitrogen percent of four grasspea ecotypes (ardabil, zanjan, mashhad and sharkord), an experiment was conducted in a controlled-environmental chamber in 2005. There were differences (p < 0.01) among ecotypes, RZT and ecotypes *RZT for root length, forage dry matter, root dry matter, nodule dry weight, nodule number, nodule cluster number, nodule cluster diameter, nodule diameter, nodule distribution (root length that has nodule) and plant nitrogen percent. Mashad and ardabil ecotypes produced the most and least nodule number at 25 and 5 degrees C, respectively. The maximum and minimum nodule cluster number were observed in ardabil ecotype under 25 and 5 degrees C RZT, respectively. Root distribution was the most and the least in mashhad and ardabil ecotypes under 25 and 5 degrees C RZT, respectively. Ardabil produced the highest dry nodule weight at 25 degrees C RZT. The least dry nodule weight was belonged to ardabil ecotype under 5 degrees C RZT. Plant nitrogen percent was the highest in ardabile ecotype at 15 degrees C RZT and the lowest in mashhad ecotype under 5 degrees C RZT. This experiment showed that at low RZT (i.e., 5 and 10 degrees C) none of ecotypes had preferred on other ecotypes in point of view measured traits except nodule diameter. Ardabile and mashhad ecotypes were better than other ecotypes at 15 and 25 degrees C RZT respectively for most traits.