Genetic diversity of backcross families derived from crossing between cultivated and wild barley using molecular markers

Plant genetic variation, during the long-term domestication of the cultivated barley, especially after the modern breeding and intensive cultivation, reduced significantly, leading to genetic erosion in this crop as well. Wild relatives of cultivated barley are potential source of valuable genetic materials for barley improvement. Genetic variation of wild species belonging to primary gene pool of barley is important in employing in barley breeding program, particularly for tolerance to biotic and abiotic stresses. Being a close relative of wild species (H. spontaneum L.) and the lack of tolerance genes among the cultivated genotypes of barley makes gene introgression the appropriate avenue to transfer desired genes such as abiotic stress tolerance.

In this research a backcross populations (BC2F1) developed from interspecific hybridization between cultivated barley and its wild relative (H. spontaneum L.) was assessed for genetic diversity using molecular markers which are valuable to assist background selection for recurrent parent.

Arliquin and POPGENE softwares were used to analyze genetic diversity and molecular variance (AMOVA) among populations, respectively. Gst and Nm parameters had an average of 0.59 and 0.34, respectively, indicating a low gene flow among nine groups of backcross families. The AMOVA results showed that majority of genetic diversity belonged to within population variation (86.48%). Nei's genetic similarity ranged from 0.41 to 0.92 which were consistent with those of genetic distance

Microsatellite markers have strong differentiation ability to discriminate the resultant genotypes from a bi-parental cross.