对黑龙江省成熟大白菜〔Brassica pekinensis (Lour.) Rupr.〕生产田采集的软腐病菌进行分离、纯化,并根据形态学特征分析了大白菜软腐病菌的种群组成。结果表明,引起黑龙江省秋季大白菜软腐病的主要致病菌是胡萝卜软腐欧文氏菌胡萝卜软腐亚种〔Erwinia carotovora(Jones)Bergey et al. subsp. carotovora〕(Ecc);利用20个Ecc菌株的混合菌对来源于不同生态型及不同地区的大白菜品种进行接种,筛选出5个鉴别寄主,以此将20个Ecc菌株划分为5个致病力类型,其中V型为优势致病菌,其分布广且致病力强。

Soft rot bacteria from Brassica pekinensis (Lour.)Rupr. in Heilongjiang Province were isolated and purified to analyze the population structure of soft rot bacteria by morphologic characteristics. The results indicated that the main pathogenic bacteria in B. pekinensis was Erwinia carotovora (Jones) Bergey et al. subsp. carotovora (Ecc). Different B. pekinensis strains were inoculated with twenty mixed strains of Eccand five differential hosts were screened, by which twenty strains of Ecc were classified into five pathogenic types. Type V was dominant pathogenic bacteria and had general distribution and strong pathogenicity.