Molecular evidence of RNA polymerase II gene reveals the origin of worldwide cultivated barley

Abstract

The origin and domestication of cultivated barley have long been under debate. A population-based resequencing and phylogenetic analysis of the single copy of RPB2 gene was used to address barley domestication, to explore genetic differentiation of barley populations on the worldwide scale, and to understand gene-pool exchanges during the spread and subsequent development of barley cultivation. Our results revealed significant genetic differentiation among three geographically distinct wild barley populations. Differences in haplotype composition among populations from different geographical regions revealed that modern cultivated barley originated from two major wild barley populations: one from the Near East Fertile Crescent and the other from the Tibetan Plateau, supporting polyphyletic origin of cultivated barley. The results of haplotype frequencies supported multiple domestications coupled with widespread introgression events that generated genetic admixture between divergent barley gene pools. Our results not only provide important insight into the domestication and evolution of cultivated barley, but also enhance our understanding of introgression and distinct selection pressures in different environments on shaping the genetic diversity of worldwide barley populations, thus further facilitating the effective use of the wild barley germplasm.

Phylogeography and Population Structure Analysis Reveal Diversity by Gene Flow and Mutation in Ustilago segetum (Pers.) Roussel tritici Causing Loose Smut of Wheat

“…Functionally, RPB2 gene is responsible for the transcription of protein-encoding genes (Sawadogo and Sentenac, 1990) and present as single-copy in all eukaryotes (Thuriaux and Sentenac, 1992). A high level of polymorphisms in this gene makes this an excellent tool to study molecular evolution and phylogenetic relationships (Matheny et al, 2007; Krimitzas et al, 2013; Wang et al, 2016; Kruse et al, 2017). Stockinger et al (2014) reported RPB2 gene as a potential marker for adequate phylogenetic resolution to resolve fungal lineages when compared to rDNA loci.…”

Archaeological and Historical Materials as a Means to Explore Finnish Crop History

“…According to molecular evidence, however, barley seems to have been domesticated more than once, with independent origins in the Fertile Crescent and in Central Asia (Morrell & Clegg 2007). Additional origins have been suggested in Morocco (Igartua et al 2013) and on the East Asian Tibetan Plateau (Wang et al 2016). As barley can withstand many different climatic and soil conditions, it subsequently spread over vast areas and became a principal dietary grain.…”

Exploring Fennoscandian agricultural history through genetic analysis of aged crop materials

“…Genome size has been estimated to about 5.3 Gb, with the full genome being composed of 2n = 2x = 14 chromosomes (IBGSC, 2012). Genetic evidence suggests that barley underwent multiple domestication events (Morrell and Clegg, 2007;Dai, et al, 2012;Ren, et al, 2013;Wang, et al, 2016), or possibly was formed from a mosaic of wild progenitors from a wide geographic region (Poets, et al, 2015). One of the geographic origins for domesticated barley was located in the Near East where domestication is estimated to have occurred some 10,000 years ago (Zohary, et al, 2012).…”

“…One of the geographic origins for domesticated barley was located in the Near East where domestication is estimated to have occurred some 10,000 years ago (Zohary, et al, 2012). Another region of importance to barley domestication was located on the Tibetan Plateau (Dai, et al, 2012;Ren, et al, 2013;Wang, et al, 2016).…”