Investigation On Germplasm Resources And Genetic Diversity Of Zizania Latifolia Around Taihu

Taihu,as China's third largest freshwater lake,have great ecological function value.Zizania latifolia living in sunny places,is a perennial grass belonging to the tribe Oryzeae,and is thus related to rice(Oryza sativa L.).Zizania latifolia is a kind of ornamental plant of perennial root herb.It belongs to the Oryzeae of Oryzoideae in the grass family.Liking warmth and sunshine,Zizania latifolia and rice are relative genus.Zizania latifolia can be traced back to the Zhou Dynasty of 3000 years ago,and Zizania latifolia has the values in ecological,ornamental,edible and medicinal.Zizaniais linnaeus divided into four kinds,including Zizania latifolia,Zizania aquatica Linn,Zizania palustris Linn,Z.texana,Zizania latifolia mainly distributed in eastern Asia,southeast Asia and Indochina Peninsula.And they,Zizania aquatica Linn,Zizania palustris Linn,Z.texana,mainly distribut in the United States,Mexico,Canada of North America and part of Europe,but those at St Max Banks of the river in the United States are endangered.There is no research about the genetic diversity of Zizania latifolia germplasm resources in Taihu lake.So this research in genetic diversity of Zizania latifolia germplasm resources,is of great significance,as it provide basis for the future investigation,collection,protection,development,utilization,promotion,and protect the diversity of species and ecological environment.Then,the biodiversity in Taihu lake will be protected,and the ecological balance will be preserved.At the same time,this research can provide the foundation for developing and using the gene of fine Zizania latifolia,and genetic evolution.The main results are as follows:(1)Distributing widely,Zizania latifolia in Taihu lake have strong growth capability.However,with the human development and unreasonable utilization,the number of Zizania latifolia is reducing year by year.From the survey of 40 Zizania latifolia samples,the number of samples that grow in the taihu lake is only 18,accounting for 45%.The 18 samples mostly in the huzhou and wujiang city near south side of taihu lake.The remaining 22 samples of wild Zizania latifolia are found in the creek,ditch or wetland,which are in 3 km~5 km away from the shore of Taihu lake,and because the personal hardening of river bank,there is no Zizania latifolia growingin the west side of Taihu lake.The length is nearly 25 km.(2)From the apparent genetic diversity analysis,the average coefficient of variation of six apparent traits of Taihu lake Zizania latifolia was 33.02%,ranging18.34%~52.22%.Further analysis on apparent traits of the 40 taihu lake Zizania latifolia communities average coefficient of variation,the average coefficient of variation of 9 Zizania latifolia communities is more than 20%,and the average coefficient of variation of 22 Zizania latifolia communities is between 10% ~ 20%,and Zizania latifolia population more than 10% accounts for more than 78%.Meanwile,analyzing the leaf shape of 40 Zizania latifolia groups in Taihu lake,we can divide them into 4 categories,and two of them present prominent characteristic in leaf surface.Taihu Zizania latifolia change a lot in genetic variation and have a high level of genetic diversity.And high levels of genetic diversity.Zizania latifolia produced high degree of genetic variation in northern of the west side of Taihu lake,the north side of Taihu lake,the southeast side of Taihu and the south side of Taihu than other orientations.(3)We analyse germplasm genetic diversity and genetic structure on 88 Zizania latifolia samples of 40 communities in Taihu lake by SSR molecular marker technology.19 pair selected SSR primers were amplified out 112 polymorphism bands,and its polymorphism band rates 99%,and groups' genetic diversity index average number is0.2763,information index average number is 0.4288,genetic distance is between0.0681~0.8224,and genetic similarity coefficient is between 0.4394~0.9342.Analysising 40 cluster by UPGMA method,we found that when the threshold is 0.195,divided 40 groups into 11 categories,analys of molecular variance witin/among populationg,the results show p<0.01,indicate differences are very significant meaning,explain the genetic structure with high disparities.Strength of genetic variability and differences of genetic structure size show that the Zizania latifolia groups in Taihu lake has rich diversity of SSR genetic type and high levels of genetic diversity.From the frequency and amount taking place notable variation in different orientations of Taihu lake,we can rank germplasm genetic diversity level of Taihu Zizania latifolia follows:the west side of the north hemisphere,north,south>southeast,east>northeast,east.