Effects of Viruses(SPVD) Grafting on Chlorophyll Content and Yield of Sweet Potato

In order to illustrate the relationship between the mechanism of yield loss caused by SPVD and chlorophyll content,6 sweet potato varieties were grafted with SPVD.The results showed that both the chlorophyll content and the yield of all tested varieties were reduced.According to the result of Xuzi 3,the effect of chlorophyll reduction occurred at early and later stage on yield loss was highly significant.In addition,there was no significant difference between the yield of treated Xu050801 and CK,which indicated that there probably existed a certain extent tolerance to SPVD.