吉林和黑龙江两省玉米北方炭疽病菌群体生物学特性分析

Biological characteristics of Kabatiella zeae population in Jilin and Heilongjiang provinces

由玉蜀黍球梗孢Kabatiella zeae引起的玉米北方炭疽病在我国东北地区普遍发生,在一些地区已成为玉米生产上的主要病害,严重影响玉米高产稳产,威胁我国粮食安全。为明确玉米北方炭疽病菌群体生物学特性,本研究于2020年7月-10月在吉林和黑龙江两省共17个地点采集了玉米北方炭疽病样品180份,并分离纯化到624个玉米北方炭疽病菌单孢菌株,通过形态学观测,科赫氏法则验证及分子生物学鉴定,确定所分离的病原菌均为Kabatiella zeae。依据菌落产黑色素能力与菌落生长情况将病原菌划分为4种不同菌落形态类型。本研究选择4株代表性菌株SH10-1(类型Ⅰ)、HB10-1(类型Ⅱ)、HN10-1(类型Ⅲ)和NA10-1(类型Ⅳ),对病原菌在两省分布比例、产孢能力、菌落生长速率,产孢方式和致病性等的比较结果显示,类型Ⅰ、类型Ⅱ和类型Ⅲ在两省份病原菌群体总数中占98.8%;类型Ⅳ在两省份中只分离到7株,其生长速率较快。对类型Ⅰ、类型Ⅱ和类型Ⅲ病原菌分析得出结论:产黑色素能力强的病原菌致病性较强且产孢能力较弱。研究结果可为玉米北方炭疽病的防治提供一定参考。

Eyespot of maize caused by Kabatiella zeae frequently occurred and has become the main disease of corn in northeast of China,which seriously affected the high and stable yield of corn and threatened the food security in China.To clarify the biological characteristics of K.zeae population,a total of 180 samples of K.zeae were collected from 17 sites in Jilin and Heilongjiang provinces from July to October 2020,and 624 strains of K.zeae were isolated and purified.The isolates were confirmed to be K.zeae by morphological observation,Koch’s rule and molecular biological identification.The purified K.zeae colonies were divided into four different types:typeⅠ,typeⅡ,typeⅢand typeⅣ,depending on the melanin-producing capacity and colonial morphology.In this study,four representative strains SH10-1(typeⅠ),HB10-1(typeⅡ),HN10-1(typeⅢ)and NA10-1(typeⅣ)were selected to compare their similarities and differences in terms of the distribution proportion of K.zeae in the two provinces,sporulation capacity,colony growth rate,sporulation mode and pathogenicity.The results showed that typeⅠ,typeⅡand typeⅢaccounted for 98.8%of the total number of pathogens in the two provinces.Only seven strains of typeⅣwere isolated from the two provinces.They had a fast growth rate,and were separately classified into typeⅣ.Through the analysis of typeⅠ,typeⅡand typeⅢstrains,it is concluded that K.zeae with strong melanin-producing ability had stronger pathogenicity and lower sporulation.These results provide a theoretical reference for the prevention and control of maize eyespot in northeastern China.