Study On Genetic Diversity In Elymus L. Wild Germplasmas

Diversity of morphological traits including thirteen biological traits and thirteen agronomic characters were analyzed using 101 accessions of Elymus L in China .Genetic diversity of the 19 accessions of above materials were studied at Microsatellite level. Twenty-six morphological characters were studied using correlation analysis.factor analysis and cluster analysis.Thirty-eight primer pairs were used in Microsatellite anlysis.The main results as follows:1 , By correlation analysis, most significant positive correlations with Plant height, Leaf length and Leaf width , most significant negative correlation with Node number of main stem and Intemode length, significant positive correlations with Number of floret spikelets and tillows, as well Plant height and Seed yield per plant, No line relationship with Spike length and Number of tillows .above correlation analysis described clearly that close relationship with every agronomic characters on Elymus L.Factor anlysis indicated that the first seven principal components accounted for 76.27% of the total variation,therefore could summarize most of the variation.By cluster analysis with sum of squares for morphological traits showed that 101 accessions of Elymus L. can be divided into 3 groups with different characteristics. Cluster analysis of morphological characters confirmed the traditional taxonomy system.2 , With an improved SDS protocol ,high quality genome DNA of the Elymus L. were obtained for Microsatellite amplification.Aoptimal reaction system suitable for the Miccrosatellite analysis in Elymus L. was established (20uL total reaction buffer) .composed by 100 ng template DNA, 0.5mmol/L Mg²⁺,lmmol/L dNTP, 1.2umol/L primer pairs, 10×PCRbuffer,1U TaqDNA polymerase.Amplificative thermal reaction program suitable for the Microsatellite analysis in the Elymus L. was devised as followings:a initial denaturation 94 for 5minutes;94℃ for 1 minute, 64 ℃—52℃ for 1 minute 30 seconds (decrease 2℃ per 3 cycles) , 72℃ for 1 minute; 27 cycles of 94℃ for 1 minute, 52℃ for 1 minute. 72℃ for 1 minute; and a final extention at 72℃ for 10 minutes.3, Thirty-eight primer pairs were used for polymorphic selection,with six (15.8%) primer pairs that produced polymorphic products.A total of twenty-six bands amplified from six primer pairs were selectes for Microsatellite analysis.4, Primers consistently indicated that 77.36% of the variation existed within the groups of the 16 accessions of Elymus dahwicus;By cluster analysis with sum of squares for Microsatellite showed that 19 accessions of Elymus L. can be divided into 5 groups with different characteristics,which could afford reference in deeper research of Elymus L.5, Classification of all genotypes based on the methods gave the result with a correlation of 0.44 between the genetic distance and taxonomic distance .this experiment demonstrated that Microsatellite analysis could reliably determine genetic relationships within a diverse array of Elymus L. varieties. Genetic relationships and the genetic similarity obtained from the analysis in present study can help in the selection of parents for breeding purposes and be uses for evaluation of varieties genetic diversity.