Study On The Genetic Diversity Of Zizania Latifolia Turcz.germplasm

Zizania latifolia Turcz. which originated from southeast Asia, belongs to perennial herbaceous species. In ancient, it was planted as a kind of cereal crop and became a kind of asexual aquatic vegetable because some segments of stems had swelled into swollen gall after being infected by Ustilago usculenta. Recently, the cultivars of Zizania latifolia in China have been various and of ample resources via long-term breeding as well as introduction among different regions. There have reports showed that Ustilago usculenta varies easily, but no specific report on genetic diversities of the plants. Therefore, to study the genetic relationship between cultivars and wild-zizania and the genetic diversity of germplasm can provide theoretical foundations for the seed breeding and domestication.Applying molecular maker of ISSR, we analyzed the genetic variety between 14 cultivated-zizania and 14 wild-zizania accessions, and probed into their genetic relationship based on the result of UPGMA clustering. Meanwhile, we studied further to verify the genetic diversity of 95 cultivated-zizania collected from the national germplasm resources collection of aquatic vegetables in Wuhan.The main results are as follows:1,The polymorphic fragments can be well amplified by PCR with ISSR. As far as the UPGMA culstering and the genetic diversity analysis were concerned, the results were similar between 14 cultivars and 95 cultivars, which proved that the repetitiveness and stability of ISSR is suit for studying the genetic diversity of Zizania plant.2,The result of UPGMA cluster of 28 cultivated and wild varieties showed that the TaiHu wild-zizania was isolated from wild ones and falled into cultivars. As to the TaiHu wild-zizania, the farthest Euclidean distance is 10.40 from the wild-zizania type and 3.98 from the cultivars, which showed the TaiHu wild-zizania has the closest genetic relationship to cultivars.3,The polymorphism analysis shows that the PPB of is only 36.15% in cultivars whereas 70.30% in wild-zizania. These data indicates that the genetic foundation of wild-zizania germplasm is enrichment and the level of genetic variance is high,but as to cultivars, these are simple and low, respectively.4,The culstering of 95 cultivated accessions shows that the cultivars are divided into 8 groups at the threshold of 1.84 and the resources from Taihu lake region exsit in every group. It showed that the Zizania latifolia germplasm has relative rich genetic basis in Taihu lake basin.