Location: Hard Winter Wheat Genetics ResearchTitle: Genetic diversity of Iranian wheat landraces and cultivars estimated by GBS Author
Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2017
Publication Date: 8/29/2017
Citation: Pour, H.A., Bihamta, M.R., Mohammadi, V., Peyghambari, S.A., Bai, G., Zhang, G. 2017. Genetic diversity of Iranian wheat landraces and cultivars estimated by GBS. Frontiers in Plant Science. 8:1293. doi: 10.3389/fpls.2017.01293. Interpretive Summary: Genetic diversity is an essential resource for breeders to improve new cultivars with desirable characteristics. We genotyped a diversity panel of 270 Iranian wheat landraces collected between 1931 and 1968 and 99 cultivars released between 1942 to 2014 using single nucleotide polymorphism (SNP) markers from next-generation sequencing analysis. The panel could be divided into three groups: two landrace groups and one cultivar group, which indicates high differentiation between landraces and cultivars and between landraces. The legacy of breeding activities in the Iranian germplasm pool and the impact of international breeding programs on modern varieties is apparent from the patterns of SNP diversity. Genetic variation was larger between groups than within groups. The high genetic diversity in Iranian wheat provides a rich genetic resource for tolerance to biotic and abiotic stresses from which breeders can select genetically distinct parents for crossing to develop improved wheat cultivars.
Technical Abstract: Genetic diversity is an essential resource for breeders to improve new cultivars with desirable characteristics. Recently genotyping-by-sequencing (GBS), a next generation sequencing (NGS) based technology that can simplify complex genomes, has been used as a high-throughput and cost-effective molecular tool for routine breeding in many crop species, including species with a large genome. We genotyped a diversity panel of 369 Iranian hexaploid wheat accessions including 270 landraces collected between 1931 and 1968 in different climate zones and 99 cultivars released between 1942 to 2014 using 16,506 GBS-based single nucleotide polymorphism (GBS-SNP) markers. The B genome had the highest number of mapped SNPs and the D genome had the lowest number of mapped SNPs on both the Chinese Spring and W7984 references. Structure and cluster analyses divided the panel into three groups with two landraces groups and one cultivar group, suggesting a high differentiation between landraces and cultivars and between landraces. Furthermore, the cultivar group can be divided into two subgroups based on whether they were derived from Iranian ancestor(s); and landrace groups can be further divided based on years of collection and climate zones where the accessions were collected. Molecular analysis of variance indicated that the genetic variation was larger between groups than within group. Genetic diversity in Iranian wheat was revealed by analysis of GBS-SNPs and thus breeders can select genetically distant parents for crossing in breeding. The diverse Iranian landraces provide rich genetic sources of tolerance to biotic and abiotic stresses, and they can be useful resources for the improvement of wheat production in Iran and other countries.