利用甘薯青枯病菌及其粗毒素测定甘薯品种抗瘟性的相关性研究

用甘薯青枯菌液及其粗毒素在温室内测定甘薯幼苗的抗病性，结果表明青枯菌菌株侵染甘薯幼苗的病情指数与其粗毒素的致萎度之间呈正相关，相关系数为0.9458(n=88)，达极显著水平；用5个不同致病力（强、中、弱）甘薯青枯菌株及其粗毒素分别接种抗、中、感甘薯品种华北48、广薯15、惠红早，结果表明甘薯品种对不同致病力青枯病菌菌株及其粗毒素的抗性呈极显著正相关，相关系数在0.9992-1.0000之间；以不同致病力甘薯青枯菌混合菌株及其粗毒素接种抗、中、感甘薯品种97-10、广薯15、惠红早，结果表明不同抗性甘薯品种病情指数与致萎度之间也存在极明显正相关，相关系数为0.9257-0.9651。说明在室内用粗毒素检测甘薯幼苗的致萎度，能够反映甘薯对甘薯瘟病的抗病或感病水平。

Resistance of sweet potato varieties to isolates of Ralstonia solanacearum and their corresponding crude toxins

The seedling of sweet potato were inoculated with Ralstoniasolanacearum or treated with their crude toxins in the greenhouse.The results showed that there were significantly positive correlation between the disease indexes of Ralstonia solanacearum infection and wilting degree of crude toxins treatment,r=0.9458.When Huabei 48、Guangshu 15、Huihongzao sweet potato varieties with different resistance were inoculated with five isolates of Ralstonia solanacearum with different pathogenicity and treated with their crude toxins,the disease index of the infection had significantly positive correlation with the wilting degree of their crude toxins treatment, r ranged from 0.9992 to 1.0000;When 97-10、Guangshu 15、Huihongzao sweet potato varieties were mix-inoculated with five Ralstonia solanacearum isolates or treated with their crude toxins, there were significantly positive correlation between the disease index of infection of the mixed pathogen and the wilting degree of their crude toxin treatment,the r value were 0.925 7-0.965 1.The crude toxins of isolates of Ralstonia solanacearum provide with a cheap and exact tool to identify the resistance of sweet potato to the pathogen.