核盘菌和三叶草核盘菌的生态特性与致病性比较

COMPARISONS OF ECONOGICAL CHARACTERISTICS AND PATHOGENICITY BETWEEN Sclerotinia sclerotiorum AND S. trifoliorum

在调查核盘菌和三叶草核盘菌发生为害的基础上，以核盘菌菌株Ｒａｐ－１和三叶草核盘菌菌株ＣＭＶ－２为代表，比较了温度及降雨等因子对菌丝生长及菌核萌发的影响。在１５～２８℃下Ｒａｐ－１菌丝生长较ＣＭＶ－２快，但在８℃下则相反；Ｒａｐ－１菌核在自然条件下萌发期间的温度较ＣＭＶ－２菌核萌发时温度高，两者菌核萌发呈现出明显的先后秩序。春季降雨的波动导致２种核盘菌的菌核萌发出现波动。离体致病性测定结果表明，核盘菌的致病性明显强于三叶草核盘菌。

In this paper,Sclerotinia sclerotiorum and S. trifoliorum were compared in the effect of temperature on mycelial growth and scleotial germination,and rainfall on the sclerotial germination,and pathogenicity in vitro against oilseed rape and chinese cabbage. The results showed that from 15℃ to 28℃,S. sclerotiorum grew more rapidly than S.trifoliorum,but reversed at 8℃. Temperature for the sclerotia of S. sclerotiorum to germinate carpogenically was higher than for the solerotia of S. trifoliorum. So,the former germinated later than the latter in spring in nature. For the sclerotia of S. sclerotiorum, carpogenic germination occurred below 20℃,which affected both the germinability and the stipe production,and decayings took place more easily from 30℃ to 35℃. The rainfall in spring resulted in a fluctuation for the sclerotia of the two pathogens to germinate. Although S. trifoliorum could infect oilseed rape and chinese cabbage in vitro,it was weaker than S. sclerotiorum in pathogenicity.The differences of S. sclerotiorum and S. trifoliorum in sclerotia germination and pathogenicity provided us with a valuable hint to evaluate the differentiation of S. sclerotiorum,a kind of worldwide-distributed pathogen.