光照与黑暗对大豆锈病菌侵染影响的研究

Effect of light intensity on infection of soybean rust

大豆锈病（Phakopsora pachyrhixi Syd．）主要以其夏孢子进行传播和侵染。应用大豆离体叶片培养技术，在24±1℃、相对湿度饱和的人工控制条件下，研究光照强度和黑暗时长对大豆锈病菌夏孢子侵染的影响。结果表明，黑暗培养8～16h，光强在600～400lx适宜大豆锈病菌夏孢子的侵染，延长或缩短黑暗培养时长，大豆锈病菌的侵染逐渐减少，增加或降低光强度，大豆锈病菌夏孢子的侵染率也逐渐降低，高光强（〉3000lx）和低光强（〈200lx）均不利于大豆锈病菌夏孢子的侵染，从高光强或低光强转至适宜光强度下均有利于大豆锈病菌夏孢子的侵染；试验结果与田间大豆锈病自然发生规律相似。

Soybean rust（Phakopsora pachyhizi Syd. ） mainly infects and spread in urediospores form mostly. In order to confirm the effect oflight intensity and dark incubation period on the infection of soybean rust urediospores,we made the experiments using the detached leaf culture technique under the temperature 24±1℃ and saturated relative humidity in controlled condition. The results showed the dark incubation period of 8- 16 h and light intensity of 600 - 400 lx was favorable for the infection of soybean rust urediospores. The infection of soybeanrust reduced gradually with extend or shorten dark incubation period. The infection rate of the urodiosperes also decreased gradually with thelight intensity increasin or decreasing. Higher light intensity（ 〉3000 lx） or lower light intensity （ 〈200 lx） was disadvantage for the infection of the urediospors and it was advantage for the infection of the urediospores with the light intensity changing to the favorable light intensity from the higher or lower light intensity. The results exhibited similarity to the natural happening of the soybean rust in the field.