Genetic variation in domesticated emmer wheat (Triticum turgidum L.) in and around Abyssinian highlands

Abstract

Because of the huge morphological variations exhibited there, the Abyssinian Highlands (Ethiopia) are thought of as the secondary center of diversity of domesticated emmer wheat (Triticum turgidum L.). The genetic diversity in 88 domesticated emmer wheat accessions from Ethiopia and other regions was analyzed using DNA sequences of parts of four genes, Acc1-A, Pgk1-B, Waxy-A and Waxy-B, which are single-copy genes in nuclear DNA. The multilocus genotypes determined by analysis using Structure enabled the 88 accessions to be divided into four clusters. Each cluster included both hulled and free-threshing subspecies, and there was no clustering corresponding to specific subspecies. Both hulled and free-threshing emmer landraces in Ethiopia had several characteristic alleles, and the gene flow between them was shown to be limited. The genetic composition of Ethiopian landraces differed from that of emmer in other regions of the world. However, their nucleotide diversity was not as high as that of other emmer populations. The large morphological diversity in Ethiopian emmer landraces must have evolved from a limited genetic background.