土壤环境因素对黄瓜枯萎病菌存活和生长繁殖的影响

Effects of Soil Environment Factors on Survival and Growth and Reproduction of Fusarium oxysporum f. sp. cucumerinum

本试验通过设定不同温度、土壤pH和土壤含水量等环境因素,研究了土壤环境因素对宁夏黄瓜枯萎病菌——尖孢镰刀菌黄瓜专化型(FOC)存活和生长繁殖的影响。结果表明:随着培养时间的推移FOC在5~35℃范围内能存活和生长繁殖,其中在20~30℃繁殖速度较快,25~28℃为最适宜的温度,高于35℃、低于5℃生长繁殖明显下降,而在45℃条件下则无法存活;pH值为5.0~9.0时,土壤中的FOC能较快生长繁殖,其中pH值为5.0时,FOC繁殖速度最快,当pH值≤4和pH≥9.0时,FOC生长明显受抑制;土壤含水量为10%~30%时FOC均能生长繁殖,而含水量为5%时其生长繁殖明显受到抑制,土壤含水量为10%~15%时,FOC生长繁殖速度最快,土壤含水量为20%~30%时FOC生长繁殖明显减缓。因此,高温、干旱、淹水处理可明显抑制土壤中黄瓜枯萎病菌的生长繁殖,从而控制枯萎病的发生或减轻连作障碍。

The effects of different temperatures,soil pH and soil relative water contents on the survival, growth and reproduction of Fusarium oxysporum f. sp. cucumerinum（FOC） were investigated by laboratory experiments in this study in Ningxia. The results showed that FOC could grow and reproduce at 5~35 ℃ with incubation time extending, and could reproduce fast at 20~30 ℃ The optimum temperature for FOC was 25~28 ℃. FOC grew and reproduced with significantly decrease above 35 ℃ and below 5 ℃ and could not survive at 45 ℃. When the pH was 5.0~9.0, FOC in soil could grow and reproduce rapidly, especially at pH 5.0, growth and reproduction of FOC was the fastest. The growth of FOC was obviously restrained under the condition of below pH 4.0 and above pH 9.0. FOC could grow and reproduce at 10%~30%soil moisture content, while it was obviously restrained at 5% soil moisture content. When the soil moisture content was 10%~15%, the FOC reproduced rapidly, and the growth and reproduction of FOC significantly slowed down at 20%~30% soil moisture content. Therefore, the growth and reproduction of FOC could be restrained by high temperature, water shortage and water flooding, so as to control the happening of FOC and alleviate consecutive monoculture problems.