Abstract:

This study analysised the DNA methylation statistic during the successive transfer culture of chrysanthemum（Dendranthema ×grandiflorum）by MSAP（methylation sensitive amplified polymorphism）technique. The results indicated that three single shoot system of the tissue culture seedling had distinct DNA hypermethylation and hypomethylation variety compared to the field materials. 929 fragments were amplified using 7 pairs of selective primers, and the mutation rate were 8.929%, 8.902% and 8.986% respectively. All the successive transfer materials had DNA methylation variety compared to the parent materials. During the variation, hypomethylation were more than hypermethylation. Along with the successive transfer culture, the diversity between the two variety pattern was smaller, and the proportion allmost similar.Meanwhile, the different individual of each single shoot system also existed DNA variation phenomenon, in the 180 individuals of quintic successive transfer culture, 18.38% bands pattern was not identical during the variational bands pattern, 2.99% was one or two individual variation, 1.72% bands pattern was stabilization after variety, while 10.68% showed unstable stochastic variety.

Key words: chrysanthemum, successive transfer culture, MSAP thchnique, DNA methylation variation, mutation rate