Genetic Diversity Of Actinidia In Heping County Of Guangdong Province

Heping County is the only area for growing Actinidia in Guangdong Province, where the cultivated and wild Actinidia resource is very abundant. In this study, we applied morphology observation, isozyme analysis and random amplified polymorphic DNA molecular makers to analyze the genetic diversity and relationships among 21 Actinidia cultivated species or varieties and wilds.By means of the spot survey and morphology observation, we found significant difference in the fruit and leaf characters of Heping Actinidia. This study showed the highly polymorphism in the fruit, leaf shape, leaf size and setae of leaf surface. With these characters ,their varieties can cluster into the same species. Different varieties can be identified with these characters.We applied Peroxidase (POD) and Esterse (EST) isozymes to analyze the different varieties and their male and female plants. We could find that the enzyme bands of the different varieties and their male and female have obvious difference, but could not find sex-related band. We suggest applying molecular makers to identify the early phase sex among the Actinidia seedlings, besides enzymatic markers.During the experiment, we tried 3 methods to extract genomic DNA, and the modified SDS method was proved suitable for the extraction of Actinidia genomic DNA, it depends on the solution that removes much of polysaccharide and phenolic substance. The extracted DNA could be used in the reaction of PCR. Through optimizing the parameters of RAPD reaction we selected a suitable program of RAPD for Actinidia genomic DNA .The program consists: First denaturing at 94℃ for 5 min, then 40 cycles( 94℃ denaturing step 10 sec, 36℃ annealing step 1 min, 72℃ extension step 1.5 min) and finished with the final extension 72℃ for 10 min.We chose 10 primers from 50 random primers for RAPD amplification. The dendrogram was obtained by application of RAPD amplification products comparison and cluster analysis. In the dendrogram the 21 Actinidia species or varieties could be classified as seven groups, there have some difference in morphology and RAPD classification. It was shown that A. deliciosa. and A. chinensis are closely related. The wild "A.fulviom" was not similar to others and classified as an independent group. The difference of the genetic relationship between the main cultivated variety "Heping .1" and "Wuzhi.2" is not obvious.