Assessment On Genetic Diversity Of Lentil (Lens Culinaris Medik.) Germplasm

Lentil (Lens culinaris Medik., 2n=2x=14) is autogamous specie and one of the oldest crops in the world, which originated in the Near East. At present, about 800 lentil accessions were maintained at the Chinese National Gene Bank, but there not any reports on their genetic diversity. 14 phenotypic traits and 14 polymorphic SSR markers were used, to evaluate a subset of 481 lentil accessions randomly sampled from the National Gene Bank on their genetic diversity. The main results were summarized as follows:1. Based on phenotypic traits,the genetic diversity of lentil genetic resources was abundant. A total of 123 observed variants have been detected based on phenotypic traits, with 8.79 variants per phenotypic trait and Shannon-weaver index (I) of 1.8149 in average. The CV of 100-seed weight, pods per plant, grain weight per plant were greater than that of others quantitative traits. However, the genetic diversity of the three mentioned quantitative traits were lower than that of others. The observed variants of qualitative traits, ground colour of testa, flower color, pattern of testa and seed shape, were 13, 8, 6 and 3 respectively. The I level of qualitative traits was accordance with their number of observed variants. The average genetic diversity of Chinese lentil genetic resources was slightly lower than that of alien ones. The highest I value (1.683) appeared within ICARDA accessions, followed by accessions (I = 1.573) from Shanxi province of China.2. Fourteen polymorphic SSR markers, which were screened from a total of 35 lentil SSR primer pairs and 110 pea SSR primer pairs. Based on SSR markers, the genetic diversity of lentil genetic resources was abundant too. A total of 87 observed numbers of alleles (na) has been detected based on SSR markers, with 6.2143 na per SSR marker and Shannon-weaver index (I) of 1.1869 in average. The results indicated significant differentiations among the 16 groups of lentil genetic resources in genetic diversity from diversed geographic origins. The genetic diversity among alien genetic resources was obviously greater than that among Chinese resources. 8 clusters were constituted from the subset of 440 individuals by using Structure 2.2 software based on SSR data matrix, the clusters were closely correlated to their geographical origins. The results of PCA, UPGMA cluster and population structure were well coincided. The genetic structure was multiplex among alien genetic resources; the genetic distance was broader among groups of alien genetic resources than that among Chinese groups of lentil genetic resources.3. The results based on phenotypic traits and SSR markers indicated and testified that center of origin was also the center of genetic diversity, as lentil genetic resources from their center of origin possessed highest level of genetic diversity.4. The results from PCA, UPGMA cluster and population structure analyses based on phenotypic traits and SSR markers, indicated that Chinese lentil genetic resources was possibly introduced from Europe at very begining.5. Compared with phenotypic traits, SSR markers is a more effective technique for assessment of genetic diversity of lentil genetic resources.