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

Li Guoqing; Wang Daoben; Zou Songbai; Yi Xianhong(Huazhong Agricultural University,Wuhan 430070)

Sclerotinia sclerotiorum,S. trifoliorum,temperature,sclerotial germination,pathogenicity

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.