| In order to expansion the genetic background of cultivars and research the diversity of wheat landrace,the SSR markers closely linked to QTL loci of main characters were applied to evaluate the diversity of Sichuan wheat landraces and analysis the relationship between the diversity based on SSR markers and morphology.The results showed that:1.The result of analysis of agronomic traits of 57 samples showed that Sichuan wheat landraces possessed some characters,including higher height(131.14cm),strong tiller capability(26.87),large number of kernel per spike.,medial spike length and number of spikelets per spike,and late heading date(152.15d),lower 1000-grains weight and yield per plant.Correlation analysis of agronomic traits showed that 1000-grains weight and spike length will be increased follow the increasing of plant height.Increase of 1000-grains weight and number of tiller can improve yield per plant,while 1000-grains weight and number of tiller have negative correlation,so that should be considered in selection of materials.Cultivars with late heading date generally possessed low 1000-grains weight.All materials were clustered into 7 groups,and the clustered result of materials was not associated with their geography distribution.Some Sichuan wheat landraces with perfect single or comprehensive traits were screened.2.Using 134 microsatellite markers which are closely linked to main characters QTL loci, genetic diversity in 62 Sichuan wheat landraces were analyzed.The 114(80.42%) polymorphic microsatellite markers were observed.A total of 547 alleles were detected by these microsatellite primer pairs,with an average of 4.76 alleles per locus,arranged from 2 to 16.Polymorphism information content(PIC) arranged from 0.032 to 0.9033, the average value is 0.574.Genetic diversity index(SI) arranged from 0.083 to 2.470, the average value is 1.118.Genetic similarity(GS) index arrangeed from 0.256 to 0.775, the average value is 0.536.The result indicated that there was higher genetic diversity in Sichuan wheat landraces.3.Genetic diversity of important SSR loci on A,B,D genome showed that:expression of Average genetic richness(Ri):A＞B＞V;expression of Average genetic diversity index (He):D＞B＞A;Expression of Genetic diversity(SI):B＞D＞A.;genetic richness(Ri): Group1＞Group3＞Group4＞Group2＞Group5＞Group7＞Group6.Average genetic diversity index(He) followed by upper to lower:5,4,3,1,2,7,6.By analyzing 21 chromosomes,2A,1B,3D have a high genetic diversity,and 4A,7A,6B have a low one. The result about the diversity of genome group and chromosomes showed the difference compare with other studies,because of different materials and markers.4.By comparing agronomic traits,quality characteristics,resistance based on SSR data,the average of genetic richness(Ri):agronomic traits(4.819)＞resistance(4.692)＞quality traits(4.692).Resistance has the highest average genetic diversity index(0.605),follow by quality characteristics(0.549),agronomic traits(0.544) is the lowest one.Comparing among agronomic traits,resistance,quality traits respectively indicate that genetic diversities of yield,farinograph parameters and anti-aphis gene were the highest genetic diversity,respectively.5.Analysis of diversity of important loci on chromosomes 1B,2A,2D,3B,4B reflected that difference locus have different deviation degrees with average genetic diversity index on each chromosome,because of different selection pressure in Sichuan wheat landrace group.Thirteen conservative heredity genome sections with higher selection signal were found,where many QTL to control important traits exists.6.The result of mantel test of the relationship between the diversity of SSR marker and 4 agonomic traits,4 quality traits and 2 stress resistance showed that:the goodness of fit of each other is poor(r=0.109,p=0.957),and r of 10 correlated characters respectively is less than 0.7(p＞0.05).It indicates that genetic diversity based on SSR loci was not significant correlated with that based on morphological traits data.Many reasons would lead to the results.
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