Association Analysis For Agronomic Traits With Issrmarkers In Mulberry Core Germplasm

Mulberry is an important perennial economic crop, and is the only feed of silkworm. Export of China’s silk fabric improved the quality of life and the sericulture is the traditional and superiority industry. The China’s cocoons outputs, raw silk production and trade accounts take up about 70% of the world. Mulberry varieties, mulberry leaf yield and quality are the decisive factors of sericulture. The improvement of mulberry variety depends on the mastery of the genetic resources of mulberry and the understanding of the genetic basis of its agronomic traits. Therefore, the analysis of the important agronomic characters of mulberry core collections is very important for the development and utilization of mulberry important agronomic traits and mulberry genetic breeding.In this paper,the author investigated and analyzed the correlation of the agronomic traits of mulberry core collections, then analyzed the genetic diversity and population structure based on the polymorphism of ISSR markers, furtherly studied correlation between agronomic traits and ISSR markers, and lastly obtained marker locis related with agronomic traits, the main results are as follows:1. Using SPSS 17.0 software, the author collected the data of 21 agronomic traits of the 90 mulberry core collections,surveyed the data mean, standard deviation, coefficient of variation of the tested core collections. And the results of statistical analysis were divided into two grades: P<0.01 and P<0.05. The results show that 21 traits quite different variation range, wherein the growth bud rate, spring-meter strip leaves, autumn meter strip leaves, spring kilograms, autumn kilograms, shoot leaf stems, leaves and stems mulberry leaf yield strain variation coefficient in more than 30%, the coefficient of variation shall spring rice leaves, leaf and stem tip Mulberry leaf stalk reaches more than 50%, the largest variation of mulberry leaf stems coefficient of variation of 178.81%, the smallest variation autumn million head cocoon coefficient of variation of 8.13%. The differences among the mulberry varieties showed traits quite different, with rich diversity, can provide a wealth of parent material mulberry breeding.2.Using10 ISSR primers of 90 mulberry germplasm for analysis of genetic diversity and population structure, a total of 90 amplified bands, including 78 polymorphic bands, the percentage of polymorphic bands was 86.92%, the average amplified bands was 9 per primer, the average amplification of polymorphic bands was 7.2. Different primers amplified bands ranged from 6 to 9. Polymorphism information content ISSR markers loci(PIC) was 0.24~0.333, the average was 0.281. The average observed number of alleles per locus was 1.8667, the effective number of alleles was 1.5468, the Nei’s genetic diversity index was 0.3129, Shannon’s’ s information index was 0.4638, indicating that ISSR variation between the tested materials, high polymorphism. By using cluster analysis and Structure UPGMA were the population structure of 90 mulberry germplasm was divided into 2 subgroups, population structure analysis and cluster analysis are consistent in some extent3.Using TASSEL2.1 software mixed linear model(MLM) matrix binding affinity(K), the population structure data(Q value), polymorphic markers tested materials data and phenotypic markers and trait data correlation analysis. After 90 ISSR loci MLM model checking, in the P <0.01 circumstances, a total of 14 sites with 10 agronomic traits associated with phenotypic variation explained by 4.15% ~ 11.39%.There are 2 different and internodal distance, the stem and leaf associated loci, and the bud-growing pecentage, leaf yield per meter branch in spring, numbers of leaves per kg in autumn, leaf shoot ratio, weight of cocoon yield per 50 kg mulberry leaves in spring, autumn cocoon yield per 10000 four-instar larves associated with each of the 1 sites; 3 each and tip of stem and leaf, stem and leaf of mulberry associated loci, among these 14 loci, associated with 2 agronomic characters of 2 loci and IS70 loci, which at the same time with the internodal distance and the stem and leaf were significantly correlated(P<0.001), of the phenotypic variance explainedrate reached 11.39% and 7.07% at the same time, the IS60 locus and shoot stem leaf andstem leaf associated with shoot, stem and leaf were significantly correlated(P<0.001), thepercentage of phenotypic variation explained by up to 10.45%. Study on the structure of protection, exploration and utilization of Mulberry Germplasm Resources in the genes of agronomic importance, and heredity of great significance.