土壤因子对玉米茎腐病菌侵染的影响

ON THE SOIL FACTORS INFLUENCING INFECTION OF CORN STALK ROT PATHOGENS

本研究系统地将玉米茎腐病菌置于土壤条件下,研究土壤温度、湿度、酸碱度、土质等因子对病菌在土壤中生长和对寄主侵染的影响。结果表明,禾谷镰刀菌(Fusarium graminearum)喜欢中性土壤和低湿的环境,不耐高温,在壤土中生长较好;瓜果腐霉菌(Pythium aphanidermatum)喜欢中性土壤和高湿环境,能耐土壤高温,在砂土或粘土中生长较好。病菌对玉米幼苗的侵染受土壤温、湿度,特别是湿度条件的影响,腐霉菌在高湿条件下致病力强,发病重。土质对发病也有明显的影响,通常砂土地发病较重。

Effect of soil factors, such as temperature, moisture, pH , soil texture and so on , on pathogens growth and infection to host in soil were systematically studied. Results suggested that mycelia of Fusarium graminearum grow better in the neutral, highly wet loam soil, but grow poorly under high temperature. Also, mycelia of Pythium aphanidermatum grow better in the neutral, highly wet sand or clay soil, and can tolerate high temperature. In addition, infection of pathogens to corn seedling is affected obviously by soil temperature, moisture, especially the latter one. In the high moisture condition, Pythnan fungus showed a high virulence to host, leading to the heavy incidence of the disease. Soil texture, to some extent, influenced disease incidence, generally disease occurs seriously in sand soil.