ARS | Publication request: Genetic differentiation and geographical relationship of Asian barley landraces using SSRs

Submitted to: Genetics and Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 9, 2010
Publication Date: May 20, 2011
Citation: Naeem, R., Dahleen, L.S., Mirza, B. 2011. Genetic differentiation and geographical relationship of Asian barley landraces using SSRs. Genetics and Molecular Biology. 34:268-273.

Interpretive Summary: Landraces are plant varieties that are adapted to specific locations and needs, and are grown and maintained by local farmers. These landraces provide a pool of genes that can be used by plant breeders to develop varieties with better yield, quality, and disease resistance. In this project, the genetic diversity of 403 landraces from seven regions in Asia was examined using DNA markers. The amount of diversity varied across the regions and within regions. Barley landraces from Turkmenistan and Uzbekistan were similar to each other, as were landraces from India, Nepal, Iran, and Iraq. Landraces from Pakistan formed a distinct group but were most similar to landraces from India. This knowledge will help breeders better select barley landraces for crossing to improve barley production in these regions and around the world.

Technical Abstract: Genetic diversity in 403 morphologically distinctive landraces of barley (Hordeum vulgare L. subsp. vulgare) originating from seven geographical zones of Asia was studied using simple sequence repeat (SSR) markers. The seven polymorphic SSR markers representing each chromosome chosen for this study revealed a high level of allelic diversity among the landraces. Genetic richness was highest for landraces from India followed by Pakistan while it was lowest for Uzbekistan and Turkmenistan. Out of 50 alleles detected, 15 alleles were considered as unique to a geographic region. Genetic diversity was highest for landraces from Pakistan (0.70±0.06) and lowest for Uzbekistan (0.18±0.17). Similarly, the polymorphic information content (PIC) was highest for Pakistan (0.67±0.06) and lowest for Uzbekistan (0.15±0.17). Diversity among populations was 40% compared to 60% within population diversity for different barley groups. Principal component analysis clustered the barley landraces into three groups to predict their domestication patterns. In total 51.58% of the variation was explained by the first two principal components of the barley germplasm. Pakistan landraces were clustered separately from the landraces of India, Iran, Nepal and Iraq while Turkmenistan, Uzbekistan landraces were clustered in a separate group.