Genetic variability and population structure of Mexican chickpea (Cicer arietinum L.) germplasm accessions revealed by microsatellite markers

Globally, the chickpea is the second most important dried grain legume after bean. Mexico occupies eighth place as producer and fourth as exporter of this legume. The cultivated genotypes are selected from advanced lines obtained from breeding programs, whose main genetic materials have come from international germplasm centers. Despite the limited number of chickpea cultivars in Mexico, there are no scientific reports on its molecular characterization and genetic variability and structure. Therefore, the present research was carried out to estimate the genetic variability of the main cultivars developed in Mexico, and others donated by International Centers (ICARDA and ICRISAT). With the analysis of ten SSR markers, a total of 51 alleles were obtained, with individual values ranging from 3 to 9 alleles per locus. The average value of PIC was estimated at 0.70, while the average value of Shannon's Information Index was 1.365, indicating the presence of a high level of genetic variability in the collection. The UPGMA and PCoA analysis showed the trend of separation of the Mexican genotypes from those of ICARDA and ICRISAT. The genetic distance was close (0.292) between the ICARDA and ICRISAT groups, while a greater distance (0.718) was obtained between the ICARDA and Mexican groups. In conclusion, the present work revealed that the most of the Mexican cultivars were grouped together and diverged from the other accessions revealing a distinct genetic nature. The accessions from ICARDA and ICRISAT did not strictly follow the grouping according to their geographical origins, maybe because the exchange of germplasm between research centers.