| The Chinese yam(Dioscorea opposita thunb.)is an important drug and food homology crop.It has a long history of cultivation in China and rich germplasm resources.It is cultivated and introduced to each other in many areas.The research on genetic background,relationship and utilization value of germplasm resources of Chinese yam is not thorough,which restricts the further development and utilization of germplasm resources of Chinese yam.Therefore,in this study,the genetic diversity and kinship of 60 yam germplasm resources and molecular markers and fingerprint map,which can provide reference for the preservation,classification and breeding of new yam germplasm resources in the future.The main results of this study are as follows:(1)The 60 yam germplasm resources had high diversity among morphological traits,leaf shape was the highest genetic diversity index,and tuber weight was the largest variation coefficient.Through cluster analysis,the Euclidean distance is calculated to be between 1.0816 and 11.4259.When the threshold value is 8.18,the tested materials can be divided into two categories.(2)580 polymorphic bands were amplified from 26 pairs of AFLP primers,with an average polymorphism rate of 78.44%.The mean value of Nei’s gene diversity index was0.1988.The average Shannon information index was 0.3149,indicating a high genetic diversity of yam germplasm.The genetic similarity coefficient ranged from 0.619 to0.922.At the threshold value of 0.74,60 Yam germplasm could be divided into two groups and two separate branches.(3)The morphological markers of the test materials were consistent with the clustering results of AFLP markers,but there were some differences.The morphological and molecular clustering analysis showed that 60 yam germplasm resources can be divided into three categories: D.opposita,D.alata and D.japonica,and were generally grown in northern China.(4)Sixty yam germplasm DNA fingerprints were constructed using two pairs of high and repetitive AFLP primer combinations E-GCT / M-ACG and E-CCT / M-TGC with high polymorphism,and each species had a unique fingerprint coding. |
