Genetic diversity analysis of Afghan wheat landraces (Triticum aestivum) using DArT markers

Crop landraces represent a source of useful genes endowing tolerance to biotic and abiotic stresses, and other agronomic traits including yield. Our study involved 446 Afghan wheat (Triticum aestivum L.) landraces collected from 16 provinces during three Japanese scientific expeditions in 1955, 1967, and 1979. The landraces and varieties were genotyped using 30,000 diversity array technology (DArT) genetic markers, of which 15,817 were polymorphic. The landraces were grouped into 15 subpopulations based on population structure and phylogenetic studies. DArT markers were used to group landraces based on their origins or collection sites and to differentiate East Asian genotypes, CIMMYT lines, and modern Afghanistan cultivars from Afghan landraces. The Afghan landraces were highly diverse compared with lines from other origins. These landraces seem to possess unique genes that might allow enrichment of the global wheat gene pool and improvements in wheat production worldwide. Our next objective is to identify genotypes with promising attributes and to conduct association mapping studies focusing on biotic and abiotic stresses.