运用聚丙烯酰胺凝胶等电聚焦法对来自江、浙两省经全国统一鉴别寄主鉴定的稻瘟病菌7群12个生理小种的16个菌株菌体酯酶同工酶进行了分析比较,结果表明:稻瘟菌菌体酯酶同工酶带有13-18条,等电点分布范围为3.00-7.20。在等电点4.15附近有各生理小种共同的酶带。同一生理小种群内不同生理小种间酯酶同工酶的相似系数一般大于0.50,不同生理小种群的生理小种间酶谱的相似系数一般为0.30-0.40,也存在少数不是同一生理小种群的小种间酶谱相似系数大于0.50的情况。供试各生理小种间酶谱均存在不同程度的差异,表现为酶带数目的多少和等电点分布的不同。来自不同省份经鉴别寄主鉴定为同一生理小种的菌株间酶谱的相似系数亦仅0.05-0.60。研究结果初步反映出供试大多数稻瘟菌菌株间菌体酯酶同工酶的相似性与致病性有关,但也受菌株来源地生态环境影响。本文还讨论了稻瘟病菌致病性容易变异但在许多情况下又具有相对稳定性的可能机制,探讨在一定范围内聚丙烯酰胺凝胶等电聚焦技术用于稻瘟菌生理分化和致病性变异监测的可能性及尚待进一步研究解决的穗题等。

The esterase isoenzymes of 16 strains of P.oryzae which belonged to 7 Chinese physiologic race-groups and 12 physiologic races from Jiangsu and Zhejiang provinces were analysed by the IF-PAGE,The results showed that the number of esterase isoenzyme bands was between 13-18 and the pI value ranged from 3.00 to 7.20.Around the pI=4.15,there were same isoenzyme bands that the 12 physiologic races possessed.The similar coefficients(SC) of zymograms among physiologic races from the same physiologic race groupwere generally larger than 0.50,but those from different physiologic racegroups were about 0.30-0.40 except for a few strains.According to the number of esterase isoenzyme bands and their pI value,every physiologic race had its specific zymogram.The SC of zymograms of the same physio-logic races from different regions was only 0.50-0.60.It seemed that the degree of zymogram'SC among physiologic races was mostly related to the pathogenicity and affected by the ecologic factors,the physiologic races of P.oryzae identified by the hosts were not homozygotes,their branch metabolic pathes were complicated and diversified.