广东马铃薯黑胫病的病原鉴定

Identification of the pathogen of potato blackleg disease in Guangdong

通过对分离自马铃薯黑胫病的病原菌在选择性CVP培养基上菌落形态观察、致病性测定及16S r DNA序列比较,鉴定出引起广东省冬种马铃薯黑胫病的病原为γ-变形菌门肠杆菌科果胶杆菌属黑腐果胶杆菌(Pectobacterium atrosepticum)。生理生化试验表明,该病原菌菌株不能在37℃生长,能使明胶液化,具有运动性、耐盐性(5%Na Cl),对红霉素不敏感;过氧化氢酶和蔗糖还原试验反应均为阳性,氧化酶、吲哚产生和磷酸酶活性试验均为阴性;可利用乳糖、麦芽糖、棉籽糖、蜜二糖、纤维二糖、柠檬酸盐和α-甲基酮葡萄糖苷,不能利用山梨醇、d-阿拉伯糖和丙二酸盐。研究结果可为广东冬种马铃薯黑胫病的综合防治提供科学依据。

Based on the colony morphology on CVP medium, pathogenicity test and 16S rDNA sequence comparison, the pathogen causing potato blackleg disease in the winter potato growing areas in Guangdong was identified as Pectobacterium atrosepticum and belonged to Gamma-proteobacteria, Enterobacteriaceae, Pectobacterium. The physiological and biochemical tests showed that the bacterium could not grow at 37℃, could cause gelatin liquefaction, had move ability and the tolerance to salt （in 5% NaCl）, and had no sensitivity to erythromycin. The bacterium also gave a positive reaction for catalase and production of reducing substances from sucrose, but gave a negative reaction for oxidase, production of indole and phosphatase. The bacterium could utilize lactose, maltose, raffinose, melibiose, cellobiose, citrate and α-methyl glucoside, but not d-arabitol, sorbitol or malonate. These results provide scientific basis for the integrated control of potato blackleg disease.