Genetic diversity and geographical differentiation of cultivated six-rowed naked barley landraces from the Qinghai-Tibet plateau of China detected by SSR analysis

Abstract

Cultivated six-rowed naked barley (Hordeum vulgare ssp. hexastichon var. nudum Hsü) is the oldest cultivated barley in China. We used 35 simple sequence repeat (SSR) markers selected from seven barley linkage groups to study the genetic diversity, geographical differentiation and evolutionary relationships among 65 H. vulgare ssp. hexastichon landrace accessions collected from the Qinghai-Tibet plateau of China, 25 accessions from Tibet (TB), 20 from Qinghai (QH) and 20 from Ganzi (GZ) prefecture in Sichuan province. At the 35 SSR loci we identified 248 alleles among the 65 accessions, 119 (47.98%) of the alleles being common alleles. We also found that the TB accessions possessed 47 private alleles, about 1.5 times more than the 31 private alleles found in the QH accessions and about 5 times more than 9 private alleles found in the GZ accessions. Generally, the TB accessions showed significantly higher genetic diversity than either the QH or GZ accessions whereas no significant difference in genetic diversity was found between the QH and GZ accessions. Partitioning analysis of genetic diversity showed that about 81% of the total variation was due to within-subgroup diversity and about 19% was clearly accounted for by geographical differentiation among the three subgroups. The distributions of alleles for most loci (71.4%) were significantly different among the three subgroups and geographical differentiation could be found according to the distribution of SSR alleles. Cluster analysis indicated that most of the accessions could be clustered into groups which basically coincided with their geographical distribution. These results suggest that Tibet might be a center of genetic diversity for cultivated barley, the cultivated six-rowed naked barley on the Qinghai-Tibet plateau of China may have evolved in Tibet and spread to Qinghai and then to Ganzi prefecture of Sichuan province.

Molecular diversity and association mapping of quantitative traits in Tibetan wild and worldwide originated barley (Hordeum vulgare L.) germplasm

“…Previous population genetic studies have found that wild barley in Qinghai-Tibet plateau of China is a rich source of genetic diversity Feng et al 2006). The results of our survey showed that Tibetan wild barley displayed the highest Shannon diversity index value (0.5254) and the highest value of gene diversity (0.3286), indicating a higher genetic diversity than other barley sub-populations.…”

“…Barley can be grown in a wide range of environments such as the Arctic, high mountains and desert oases (Harlan 1976). It was suggested that worldwide cultivated barley originated from either the Fertile Crescent (Ancient Egypt, the Levant and Mesopotamia) (Harlan 1976), or the Qinghai-Tibet plateau region in China (Vavilov 1926;Brücher and Å berg 1950;Feng et al 2006).…”

“…Genetic diversity of wild and cultivated barley have been characterized using RFLPs (Graner et al 1990;Petersen et al 1994;Russell et al 1997), RAPDs (Dawson et al 1993;Frank and Ana 2001), AFLPs (Turpeinen et al 2003), and SSRs (Saghai-Maroof et al 1994;Struss and Plieske 1998;Matus and Hayes 2002;Feng et al 2006). It has been demonstrated that SSR markers possess a number of advantages over other types of molecular markers, such as codominance, highly polymorphisms, locus specificity, good reproducibility, and random distribution throughout the genome.…”

Genetic diversity of ICARDA’s worldwide barley landrace collection

“…It's used for animal feed, brewing malts, and human consumption Brown 1992). Considered as a model species for genetic analysis thanks to its widely available genetic information , an extensive amount of data has been produced from genetic diversity surveys of molecular marker loci in wild and cultivated barleys at national, regional and worldwide levels during the past decade (Orabi et al 2007;Pandey et al 2006;Brantestam et al 2006; Italic values indicate regional totals GTTTCTT 1 , Addition to the 5 0 -end of reverse primer; PCR*, Code of PCR condition detailed in Table 3; Chr 2 , Chromosome; g Genic marker Malysheva-Otto et al 2006;Feng et al 2006;Chabane et al 2005;Hou et al 2005;Hamza et al 2004;Baek et al 2003;Matus and Hayes 2002;Struss and Plieske 1998;Will iam et al 1997). Microsatellites or simple sequence repeats (SSRs) are highly variable markers that are commonly used in population genetic studies for the analysis of gene flow, parentage analysis, and studies on genetic diversity (Pfeiffer et al 1997;Streiff et al 1998;Jones and Ardren 2003).…”

Genetic diversity of Ceratoides arborescens, a species endemic to China, detected by inter-simple sequence repeat (ISSR)

“…All these traits together have probably resulted in its presently high level of genetic diversity at the species level. Moreover, many researchers have considered that habitat fragmentation, location, and population size have high impact on genetic diversity within populations (Feng et al, 2006;Arunkumar et al, 2012;Liu et al, 2013;Ghaffari et al, 2014). In the present study, the desert steppe group (PA, PB) exhibits a higher degree of genetic diversity than the typical steppe group (PC, PD, PE, and PF), This result was consistent with population size, suggesting that fragmented habitats, migration (decreased or absent) between populations, and genetic drift have probably contributed to the loss of diversity in the populations, especially in PF.…”