Study On Genetic Diversity Of Echinochloa Crusgalli From Cold Areas

Barnyard grass from Heilongjiang is rich in resources and diverse in varieties,but their distribution is chaotic and the genetic basis is complex,which brings great difficulties to their popularization and application.In order to further popularize and develop these high quality barnyard grass,the research should be strengthened on the distribution,resource collection,systematic classification and genetic diversity of barnyard grass population.In this study,43 varieties of barnyard grass were collected in cold areas,and the genetic diversity of barnyard grass was studied with morphological and ISSR molecular markers.The purpose is to provide references for the classification,identification and utilization of barnyard grass germplasm resources in Heilongjiang.?1?In this study,21 morphological traits were selected to analyze the genetic diversity of barnyard grass in cold areas.The results showed that 15 traits showed genetic differences to different degree.The diversity indices of quality traits ranged from0.20 to 1.36,and the coefficient of variation of quantitative traits ranged from 6.40%to23.28%.It shows that the barnyard grass is rich in genetic diversity and possesses great potential in germplasm variation and innovation.?2?All the materials were divided into four groups through cluster analysis.The second group is characterized by large inflorescences and spikelets,suitable for processing into fine feed or raw materials for brewing.The fourth group of germplasm characteristics of the plants is tall and stout,with lush stems and leaves,which can be used as a quality forage to further promote.In addition,the total germplasm was also divided into four major categories through the principal component analysis which is consistent with the clustering results.?3?As a result of variance analysis and significance test 11 morphological traits showed significant differences among the four groups,including leaf length,leaf width,panicle length,raceme length,spikelet length,main stem diameter,high,spikelet threshing,the degree of panicle inflexion,whether the raceme toward the spindle and the raceme curvature.These traits are important indicators to identify barnyard grass in the cold areas.?4?The ISSR-PCR system of barnyard grass was optimized by orthogonal experimental design.The optimized system for barnyard grass ISSR-PCR analysis contained 0.3mmol/L dNTPs,0.2?mol/L primer,0.75U Taq DNA polymerase,20ng DNA template and 2?L 10×PCR Buffer(Mg²⁺plus).A total eight primers for ISSR-PCR of barnyard grass were selected,which are UBC808,UBC826,UBC827,UBC856,UBC857,UBC888,UBC889 and UBC890.An optimal annealing temperature of each primer was determined by using temperature gradient PCR.?5?ISSR-PCR molecular analysis of 43 varieties of barnyard grass was conducted with the optimized system.101 ISSR bands were amplified with eight primers.87 bands of them were polymorphic,representing a 86.14%polymorphic rate.The genetic diversity of 43 tested barnyard grass was analyzed with Popgene software.The results showed that the genetic diversity of barnyard grass germplasm was relatively large.With cluster analysis 43 tested barnyard grass was divided into 4 groups,and the morphological differences among different groups were significant.