安徽省棉花枯萎病菌生物学特性及酯酶同工酶分析

Biological Characteristics and Esterase Isozyme Analysis of the PathogenicFungus Causing Fusarium Wilt of Cotton in Anhui Province

研究温度、pH值以及碳源、氮源对棉花枯萎病菌菌丝生长速率、菌丝干重和分生孢子产生量的影响,并对不同棉花枯萎病菌菌株进行了酯酶同工酶分析.结果表明,该病菌在10～35℃下都可生长,最适生长温度为25℃;在pH4～10范围的PDA培养基上均能生长,最适pH值为6～7.蔗糖作碳源时,该病菌在PDA平板上生长最快,分生孢子产生量最大,但菌丝干重略低于可溶性淀粉处理;氮源以脲最佳,其次为硝酸钠和硝酸铵.酯酶同工酶分析结果表明,供试的15株棉枯萎病菌株的酯酶同工酶主酶带有明显不同,可将其分为4种类型,酯酶同工酶酶谱类型和致病力有较密切的相关性.

The effects of temperature, pH, carbon and nitrogen sources on the mycelium growth,dry mycelium weight and conidium production of Fusarium oxysporum f. sp.vasinfectum (Atk.) Synder & Hansen, the pathogenic fungus causing Fusarium wilt of cotton in Anhui were studied, and the esterase (EST) isozyme analysis of the 15 tested isolates was conducted in this paper. The results showed that for the mycelia growth of F.oxysporium f.sp.vasinfectum,the range of temperature was between 10℃ and 35℃, the optimum being 25℃, and the range of pH was 4~10, the optimum being 6~7. Sucrose was the best carbon source for the mycelium growth of the fungus,but it was junior to soluble starch for the increase of the dry weight of mycelium. Among the tested nitrogen sources,urea was the best, next was sodium nitrate, and then ammonium nitrate for the mycelium growth of the causal organism. The results also indicated that there was obvious difference in the main enzyme zones of EST isozymes among the 15 tested isolates, and they could be divided into four types. The type of EST isozymes was related to the pathogenicity. It was suggested that the electrophoresis of EST isozyme analysis might be useful for distinguishing different pathogenicity types of F.oxysporium f. sp.vasinfectum.