温度胁迫对棉花黄萎病菌致病力的影响

The Effect of Temperature Stress on Pathogenicity of Verticillium dahliae Kleb in Cotton

在不同温度条件下对棉花黄萎病菌同一菌株进行继代培养至11代,试验结果表明:温度对棉花黄萎病菌的致病力有明显的影响。无论在何种温度条件下(15～30℃)均表现随着培养代数的增加,病原菌的致病力先有减弱趋势,而后又逐渐回升。高温胁迫对病原菌致病力的影响较明显,30℃条件下培养至11代,病原菌的致病力明显高于对照,即较高温度较长时间的选择压力,使病原菌的致病力明显提高。温度对病原菌的室内培养特性也有影响,随着温度的升高,菌株产生菌核减少。

A same strain of Verticillium dahliae Kleb in cotton was cultured one generation after another till to the 11th generation under four different temperature levels(15～30℃). The result showed that temperature had obvious effect on Pathogenicity of Verticillium dahliae Kleb. Under four different temperature levels the Pathogenicity became weaker at first and then stronger along with the generation going ahead. The higher the temperature, the more obvious the effect on Pathogenicity of the strain. Pathogenicity of the 11th generation under 30℃ is obviously stronger than that of the contrast. It also indicated that Pathogenicity of a strain is becoming stronger under the stress of higher temperature and longer time. The temperature also takes effect on the characteristics of the strain's indoor culture. The higher the temperature, the fewer the nuclei.