| Barley is one of the ancient crops, and also the fourth ranking staples after wheat,maize and rice in the world. The annual wild barley (Hordeum Spontaneum) ofQing-Tibetan Plateau is a very important resource for the research of genetic diversity andspecies evolution in barley. A total 175 barley varieties, including 40 Qing-TibetanPlateau annual wild barley lines, 46 European barley varieties, 81 American barleycultivars and 8 Australian domesticated barley varieties,were used to detect their geneticdiversities, based on 16 agronomic character, proteins and photosynthesis rate, and 42SSR molecular markers. The main results were as follows:1. The results indicated that there were significant or slightly significant differencesamong all germplasm resources in agronomic characters. In six-rowed barley, variancecoefficient of the flag leaf area, awn length in wild barley were 49% and 44%,respectively. The genetic variance of single plant seed numbers, the single plant fact seednumbers, and the single plant spikes was highest in American barley, with the coefficientof variation of 42%, 43%, and 35% respectively. The genetic coefficient of variation ofthe thousand grain weight, kernels per ear, the spikelet numbers per spike, and kernelweight per main spike in Australian barley were 33%, 60%, 36%, 55%, and 50%separately.In two-rowed barley, the Qing-Tibetan two-rowed wild barley showed a strongestgenetic coefficient of variation, and the single plant fact seed numbers, single plant kernelweight, single plant spikes, awn length were 46%, 51%, 38%, and 46%. The Europeanbarley displayed the highest coefficient of variation of the fact seed numbers per spike,and kernel weight per main spike of 49% and 44%. The American barley showed thelargest variation of thousand grain weight, and spike density of 21% and 20%. TheAustralian domesticated barley indicated the largest variance of the flag leaf area andmain spike lengh of 74% and 20% separately.2. Among all the barley germplasm resources investigated, Qing-Tibetan plateauwild barley displayed the highest average protein content of 13.52%, while the Australianvarieties showed the lowest that of 12.22%. Data from One-Way ANOVA demonstratedthat average protein content of Qing-Tibet wild barley was not significant when comparedwith American barley on the level of 5% and 10%, but was significant with Europeanbarley varieties and Australian domesticated barley. The average protein content ofQing-Tibetan plateau wild barley showed significant difference when compared withEuropean barley, Australian barley and American barley. The excellent germplasm resource can be used to feed stuff breeding. For the genetic variance coefficient,Australian barley, Qing-Tibetan wild barley and European barley showed a range of 6.7%,5.9% and 4.0% respectively.3. American barley and Qing-Tibetan plateau wild barley showed the highest level of14.59μmol.m-2.s-1 and the lowest level of 13.21μmol.m-2.s-1 in the photosynthesis rateanalysis, respectively. One-Way ANOVA analysis on the level 5% and 1% detected nosignificant difference of photosynthesis rate among all the regions. Australia barleydisplayed the highest genetic variance coefficient of 31%.4. Clustering analysis with UPGMA illustrated that 175 accessions could be dividedinto five groups at the level GS 0.51. Group one, two, five in total had 30 barley varieties,and were mainly composed of Qing-Tibetan Plateau wild barley. Group three was largelymade of American barley cultivars. European barley, Australian barley togethercontributed to the biggest proportion of group four. Barley varieties from differentgeographical regions could be generally clustered into the same group when they showednear genetic distances.5. The genetic diversity was analyzed by 42 SSR markers. 40 SSR primers gavestable amplified bands, and 230 alleles were detected in the barley materials. The averagenumber of alleles per SSR locus was 5.75 with a range from 2 to 11. And the value ofpolymorphism information content (PIC) for each SSR primers ranging from 0.157 to0.874, with a mean of 0.718. The PIC of Qing-Tibetan Plateau wild barley varied from0.169 to 0.879, with an average of 0.713; the PIC of European barley was during 0.081and 0.867, with a mean of 0.691, the PIC of American barley showed a range from 0.202to 0.868, with an average of 0.709; while the PIC of Australian barley varieties rangedfrom 0 to 0.844, with an average of 0.656. It furthermore confirmed that Qing-TibetanPlateau wild barley has the highest genetic diversity.6. Both SSR markers and UPGMA interpreted barley varieties from differentgeographical regions had manifest geographical regions division. Since the varieties inthe SSR map and UPGMA map was not one to one, there was no obvious correlationbetween them.
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