Genetic Diversity Of Elymus Nutans In The Northwestern Plateau Of Sichuan Province

Genetic diverrity of wild Elymus nutans from northwest plateau of Sichuan province as thecentral materals were determined using morphological markers, karyotype analysis and Gliadinmarkers.The main results showed that:1 Result from Shannon-weaver index analysis showed that there was an abundant geneticdiversity(H'=1. 86748) among these Elymus nutans populations in ear characteristics, the geneticvariation within populations (71.91ï¼…) was greater than that among populations(28.09ï¼…). Genetic variation is different in each trait, in which the weight of single ear had themost variation and the Lemma length variation was least. Cluster analysis showed that 12populations could be categorized into 4 groups, and each group had its evident diversity both inEar and Spikelet characteristics. Principle component analysis results indicated that 4 of thecharacters measured: Spikelet, Palea and Lemma, glume, and some stable heredity factors werethe main sources of ear characteristics variation.2 Karyotype analysis result show that the Elymus nutans in northwest plateau of Sichuanprovince was a stable hexaploid species, the main variation was in structure of chromosome, in 12materials, 3 of them has SAT. And there were 5 karyotype formulae as follows:2n=6x=34m(2SAT)+8sm(203024, 205090, Y2097);2n=6x=38m+4sm (202068, 205106, Y2091, Y2095,Y2120);2n=6x=36m+6sm (205116, 205218);2n=6x=32m+10sm (205097);2n=6x=30m+12sm(205096). The karyotypes belong to 1A or 1B, in which 205097,Y2905 and Y2907 belong to 1B,and the others belong to 1A.3 Gliadin markers based on A-PAGE were used to analyze genetic diversity and geneticerelationship among 55 Elymus nutans accessions from four provinces and regions (northwestplateau of Sichuan province, Xin jiang, Tibetr Mongolia and Qinghai), based on the results,gliadin fingerprinting database was established. According to comparing the gliadin of thematerials from northwest plateau of Sichuan province with fingerprinting database, the followsresults were obtained: (1) Total of 41 gliadin bands were detected in accessions from northwestplateau of Sichuan province, 87.80ï¼…were polymorphic, which was fewer than all the accessions (45 gliadin bands and 87.80ï¼…were polymorphic). The Shannon index, Simpson index andgenetic similarity distance in Sichuan accessions were also less than total accessions. Theseresults suggested that there was smaller genetic polymorphism in Sichuan accessions than totalaccessions, but it own 2 particular bands (40ï¼…of total 5 particular bands), this result showed thatthe wild Elymus nutans in northwest plateau of Sichuan province had particular geneticfeatures. (2) The accessions from northwest plateau of Sichuan province can be clustered into asingle group know from other materials, and the findings implied that a correlation among gliadinpatters and altitude. (3) Gentice differentiation between and within 4 eco-geographical groups ofElumus nutans was estimated by Shannon's diversity index, which show that 49.4ï¼…geneticvariance existed within group, and 50.6ï¼…genetic variance was among groups. This result mightbe correlative to mainly self-pollinated breeding system of Elymus nutans.