影响水稻稻瘟病菌侵染过程的生态因子研究

通过田间和室内模拟等方法研究了水稻生长阶段，品种抗性，温度，降雨量和施N量等因子对稻瘟病菌侵染过程的影响。结果表明，水稻叶表单位面积病菌孢子附着量与水稻不同生长阶段呈负相关关系。稻瘟病潜育期与温度关系密切，在10℃-33℃范围内，以28℃条件下潜育期最短，小于℃，大于28℃的潜育期相应延长；病菌孢子侵染比值与水稻生长阶段呈负相关关系；稻叶表病菌孢子附着率在孢子与叶表接触后的5h内，与降水强度和降水持续时间密切相关，5h后影响变小；在一定条件下，稻瘟病扩展性病斑与非扩展性病的比值，扩展性病斑扩展的最大面积与水稻品种抗性和当时病斑所处叶位有关。

Effects of ecological factors on infection process of Pyricularia grisea Key words Pyricularia grisea, Infection process, Ecological factor

Rice blast is one of the main rice diseases. In order to discuss the occurrence regularity and improve the veracity of forecasting, the effects of ecological factors on infecting process, such as rice growth period, cultivar resistance, temperature, precipitation, and fertilization of nitrogen, were studied quantitatively. The results showed that adhering conidia on leaves, or ratio of infection was negatively correlative with the growth period of rice. The latent period of Pyricularia grisea was closely related to temperature, and within the range from 10 degrees C to 33 degrees C, the latent period was the shortest at 28 degrees C. The ratio of conidia adhering on leaves was also closely related to precipitation, especially the intensity and duration of precipitation in the first 5 hours after conidia contacting leaves, and there was no obvious effect after 5 hours. Under certain conditions, the ratio of expansive lesions to non-expansive lesions, the maximum area of expansive lesions, and variety resistance of rice were related to the rank of leaves.