Evaluation Of Dioscorea Fordii Prain Et Burk. Germplasm Resources From Midwestern Hainan

Dioscorea fordii Prain et Burk. (D. fordii) which is known as a wild yam, belonging to Dioserea genus of Dioscoreaceae family, is more and more popular as the cash crop of food and medicine. As one of the origin of D. fordii. Hainan Province has rich wildlife resources. In this study,morphological characteristics, SRAP molecular markers, nutrition indicators and determination of resistance to anthracnose were used to overall evaluate of 76 D. fordii. germplasm resources. The objectives are to assess the level of genetic diversity among different cultivars of D. fordii, to get excellent germplasms and to establish the evaluation system of D. fordii. The main results were as follows:(1) 76 germplasm accessions of D. fordii were evaluated by 31 morphoagronomic descriptors that including ground and underground parts. Different D. fordii had different morphological characters. The shapes of leaf base had hastate, arrow and ear-shaped. The color of petiole end were green, purple or color purple. The shapes of tuber were rich, such as stick, rod, cylindrical and flat cylindrical. By Ntsys software clustering, the dendrogram of clustering was construted. 76 D. fordii germplasms were divided into 10 groups when the Euclidean distance was 6.71, and different groups had different obvious morphological.(2) 49 SRAP primers were amplified for 76 D. fordii, and the polymorphic sites were 610. The evaluation of genetic diversity showed: the rang of genetic similarity coefficient between D. fordii was 0.5016?0.8590, with a mean of 0.6431, and Shannon index (?) was 0.401, Nm was 2.13, revealing a low level of genetic variation in them. The germplasm resources could be divided into five clusters when the genetic similarity coefficient was 0.65 and different with tne ten culsters of morphology. The genetic diversity of five clusters showed: pop 1> pop 5> pop 4> pop 2> pop 3.(3) Using D. opposita Thunb cv. Tiegun (DoT) as comparison, D. fordii were measured in dry matter weight, starch content, soluble sugar content, crude polysaccharide content and protein content. The results showed that the D. fordii had a rich nutrient and a high nutritional value. Nutritional quality of D. fordii varied significantly. There was a certain correlation between the various nutritional quality. Dry matter content and the content of polysaccharides all had a highly significant negative correlation with soluble sugar content. The average of dry matter content, starch, soluble sugar content, crude polysaccharide content of D. fordii were higher than that of DoT, except the average of protein content. D. fordii were classified into 7 groups by using cluster analysis.(4) 76 D. fordii were used to anthracnose resistance identification by using vitro leaves inoculation method. 7 days later, the survey results showed that: 15 germplasms showed high resistance, 21 germplasms showed anti, 14 germplasms showed in a sense,the remaining 26 showed a high sense. Resistant D. fordii had 36 and susceptible germplasm had 40. The resistance of anthracnose were different between different D.fordii.