| China is the origin centers of mulberry and is also the cradle of the world sericulture.Mulberry is perennial and the only food for the silkworm to successfully complete the life cycle.There is a direct influence of the yield and quality between mulberry leaf and sericulture.The main purpose of genetic breeding of modern mulberry resources is to improve the yield,quality,adaptability and disease resistance of mulberry trees.Morus atropurpurea Roxb.is mainly distributed in China’s southern main silkworm areas(the province of Guangdong and the region of Guangxi autonomous)and tropical southeast Asia,which forms a rich variety of mulberry germplasm resources.This type of mulberry characteristics mainly manifested as : early germination,long hairline,cutting and cutting,long and slender branches,small leaf shape,weak cold resistance and so on.With densely and white-colored hairs inside the stigma,the female flower of Morus atropurpurea Roxb.with short styles but not obvious.In this paper,81 Morus atropurpurea Roxb.mulberry germplasm from national mulberry genebank in ZhenJiang were used as the experimental material to analyze their correlation among 36 agronomic traits.The genetic diversity and population structure were analyzed by using the polymorphism of 10 ISSR(inter-simple sequence repeat)markers,and the correlation between genetic markers and agronomic traits was further analyzed.The main results are as the following:1.In this study,the survey of 81 parts mulberry collection 36 agronomic traits using SPSS 17.0 software to analyze the field survey datum is divided into two levels.The result shows that the variation range of 36 traits are quite different,where in TNA、LN,the variation coefficient is more than 30%.The variation coefficient of LYPP、LA and LB even reaches more than 50%.The variation coefficient of FSR,441.48%,is the largest of all,and the smallest one is ACY,only 9.6%.The differences among the mulberry varieties showed traits are quite different and wide diverse,which provides rich material for the study of genetic breeding of mulberry trees.2.A total of 90 bands were amplified with 10 primers,including 69 polymorphic bands.The percentage of polymorphic bands is 76.67%.The amplified bands of different primers ranged from 5 to 12.The amplified bands’ average was 9 per primer,and the polymorphic bands’ average is 6.9 per primer.The analysis result of the genetic diversity shows that the average observed number of alleles per locus was 1.7667,the effective number of alleles was 1.5514,the Nei’s genetic diversity index was 0.3083,Shannon’s’ s information index was 0.4489,indicating that the ISSR variation and polymorphism among the 81 tested materials are quiet high.Population structure analysis and cluster analysis are consistent in some extent by using cluster analysis and Structure UPGMA.The population of 81 mulberry germplasm was divided into 2 subgroups.3.On the basis of field investigation,ISSR-PCR molecular markers,genetic diversity and population structure,Using TASSEL2.1 software mixed linear model(MLM),take the population structure data(Q value)as the concomitant variable,do the correlation analysis between matrix binding affinity(K)and 90 phenotypic markers and trait data.From the result we can see,among the 90 sites there are 18 sites associated with 15 agronomic traits.Under the condition of P<0.01.And the phenotypic variation explained by 6.78%~11.63%.There are 8 site associated with LL,Among these 37 sites,there is 4 site associated with 2 agronomic characters at the same time.The study has an important significance on the structure of protection,exploration and utilization of the agronomic characters genes of Mulberry germplasm resources,as well as the genetic breeding. |
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