Genetic diversity ofSorghumhalepense(L.) Pers. in Iran as revealed by IRAP markers

Abstract

Sorghum halepensegrows in a vast range of ecological regions of Iran. In this study, inter-retrotransposon amplified polymorphism (IRAP) markers were used to assess the genetic diversity of 38 accessions ofS. halepenseand two accessions ofSorghum bicolor(used as out groups) collected from different regions of Iran. In total, 180 DNA fragments were amplified from eight combinations of IRAP primers, from which 178 (98.9%) were polymorphic. The IRAP-based trees and two-dimensional plot of principal coordinate analysis demonstrated six different groups corresponding to their geographical origin in Iranian germplasm ofS. halepense: (1) in the south-west region; (2) in the west along the Zagros Mountains; (3) in the north-west of the country; (4) in the centre of the country; (5) and (6) in the northern region along the eastern and western coast of Caspian Sea. The most variable populations were found in the centre and the west of Iran. The results showed high gene flow among different regions, although the south-western accessions were well differentiated from those growing in other regions. The accessions collected from western coast of Caspian Sea were differentiated from neighbouring regions in both morphological characters and IRAP data. The measured genetic distances were independent of geographical distances. This survey demonstrates high genetic dynamism in Iranian germplasm ofS. halepenseand indicates that the present germplasm is of great value in terms of sampling for new alleles for crop improvement.