Abstract:

【Objective】 To compare the biological characteristics of defoliating cotton verticillium wilt pathogens from Changji and Shawan and clarify the control effects of carbendazim, ethyl allicin, ethyl azolone, that is, Bacillus subtilis and Trichoderma harzicum, which were commonly used in local production, on cotton verticillium wilt will be determined, and efficient and effective agents selected to guide the control of cotton disease. 【Methods】 The mycelial growth rate method was used to investigate the main biological characteristics of various pathogenic bacteria through adaptive growth of different ions, pH, carbon sources, and temperature. Meanwhile,the toxicity of five pesticides was measured indoors. 【Results】 The optimal temperature for the growth of pathogenic bacteria in Changji City and Shawan City was 20-25 ℃, the optimal ion culture medium was Ca²⁺, the optimal pH was 5-7, and the optimal carbon source was sucrose. All the 5 tested drugs had significantly different inhibitory effects on various pathogenic bacteria. Carbendazim, Bacillus subtilis and Trichoderma harzianum had strong inhibitory effects on pathogenic bacteria. The EC₅₀ of carbendazim, Bacillus subtilis and Trichoderma harzianum to Changji was respectively 0.292,3-0.819,3 μg/mL,1.661×10^-2-2.695×10^-2 μg/mL, 0.101,5-0.884,6 μg/mL, for Shawan, 0.358,8 -5.694 μg/mL, 1.813 ×10^-2-2.727 ×10^-2 μg/mL,0.181,0-0.608,8 μg/mL, respectively, while allicin and azolidinone had the worst control effect on pathogenic bacteria, with an EC₅₀ of 71.04 μg/mL、111.6 μg/mL in the Changji area and in the Shawan area 79.22 and 171.7 μg/mL. 【Conclusion】 In Changji and Shawan, 25 ℃ is the ideal temperature for the growth of several pathogens, and the ideal ion medium is the one that contains Ca²⁺. Different infections develop fastest in pH values between 5 and 7, therefore acidic environments are ideal for their growth. Additionally, they can withstand alkaline conditions well. Microsclerotia develop quickest on culture media containing sucrose as the carbon source and are more likely to occur in alkaline settings. Carbendazim, Bacillus subtilis and Trichoderma harzianum have strong bacteriostatic effects on cotton Vverticillium wilt in Changji and Shawan, which can be used to prevent and control the cotton disease.

Key words: defoliating pathotype; Verticillium wilt; biological characteristics; mycelial growth rate method; toxicity determination

摘要：

【目的】比较研究新疆昌吉市和沙湾市落叶型棉花黄萎病病原菌的生物学特性,分析的多菌灵、乙蒜素、唑酮乙蒜素、枯草芽孢杆菌和哈茨木霉菌5种农药对棉花黄萎病的防治效果,筛选出高效的药剂用于指导棉花病害防治。【方法】采用菌丝生长速率法,通过不同离子、pH值、碳源及温度生长的适应,分析各病原菌的主要生物学特性,并对5种农药进行室内毒力测定。【结果】昌吉市和沙湾市各病原菌生长最适温度为20~25℃,最适离子培养基为Ca²⁺,最适pH值5~7,最适碳源是蔗糖。5种供试药剂均对各病原菌具有明显的抑制效果。多菌灵、枯草芽孢杆菌、哈茨木霉菌对病原菌的抑制作用极强,昌吉市多菌灵、枯草芽孢杆菌、哈茨木霉菌其抑制中浓度EC₅₀值仅分别为0.292 3~0.819 3 μg/mL、0.016 61~0.026 95 μg/mL和0.101 5~0.884 6 μg/mL,沙湾市EC₅₀值分别为0.358 8~5.694 μg/mL、1.813×10^-2~2.727×10^-2 μg/mL和0.181 0~0.608 8 μg/mL;而乙蒜素、唑酮乙蒜素对病原菌的防效最差,其EC₅₀在昌吉市分别高达71.04 、111.6 μg/mL,沙湾市分别为79.22、171.7 μg/mL。【结论】昌吉市、沙湾市的各病原菌最适生长的温度为25℃,含Ca²⁺培养基为最适离子培养基。各病原菌在pH 值5~7时生长速率最快,最适生长环境为酸性环境,对偏碱性环境也有较好的耐受性。微菌核在偏碱性的环境下更易形成,在以蔗糖为碳源的培养基上的生长速率最快。多菌灵、枯草芽孢杆菌、哈茨木霉菌对棉花黄萎病菌有强抑菌作用,可在昌吉市和沙湾市用于防治棉花黄萎病。

关键词: 落叶型棉花, 黄萎病, 生物学特性, 菌丝生长速率法, 毒力测定