Molecular analysis of Lathyrus sativus L. (grasspea) and related Lathyrus species

Eight Lathyrus sativus L. accessions from a variety of geographic origins w ere used to study intraspecific genetic diversity using RAPD analysis. Four teen decamer primers produced 64 amplification products, 50% of which were polymorphic between the samples. Jaccard's coefficient of genetic similarit y was calculated between samples and a dendrogram was constructed by an unw eighted pair-group method with arithmetical averages (UPGMA). The dendrogra m showed that most of the L. sativus plants clustered into accessions or co mmon geographical areas. The average genetic similarity coefficient within accessions was 0.12 and between accessions was 0.20, indicating a low level of intraspecific genetic variation. Interspecific genetic diversity and ph ylogenetic relationships of eight Lathyrus species, including L. sativus an d Pisum sativum L. (field pea) were examined using 14 decamer primers which produced 283 amplification products. All amplification products were polym orphic across the nine species. In the dendrogram the Lathyrus species clus tered into three distinct groups which correlated with the Sections Lathyru s, Clymenum and Linearicarpus. This supports traditional taxonomic classifi cations of the genus Lathyrus which are based on morphological traits. Of t he species from Section Lathyrus, L. gorgoni and L. cicera were the most si milar to L. sativus. The results suggest that a strategy of breeding for pr oducing lines of L. sativus with increased genetic variation would be effec tively achieved through hybrid production between accessions from wide geog raphic areas particularly the Mediterranean area and the Indian subcontinen t. However, the most effective method would be introgression of germplasm f rom other species in Section Lathyrus.