玉米品种对小斑病的抗性分析及品种间作的控病效果

采用喷雾接种法和田间自然诱发法,测定福建省11个鲜食玉米品种在苗期和成株期对玉米小斑病的抗性,并探讨抗感病玉米品种间作对病害发生的影响。结果表明,不同玉米品种在苗期对301株小斑病菌群体均表现出不同程度的抗、感病性,品种之间对菌株群体的抗性频率为32.23%～72.76%,其中榕甜1号和永珍7号的抗性频率较高;供试玉米品种在成株期对小斑病的病情指数存在显著差异,其中榕甜1号、永珍7号和闽甜4号均表现为中抗。田间抗感病玉米品种间作试验发现,在福州试验田感病品种粤甜22分别与抗病品种榕甜1号、永珍7号间作后的病情抑制率为33.78%和25.41%;在屏南试验田相同的间作处理两年病情抑制率分别达58.35%、21.05%和52.56%、46.42%。

Resistant Analysis of Corn Varieties to Southern Corn Leaf Blight and Effects of Varieties Intercropping on the Prevention of the Disease

The resistance of 11 fresh corn varieties in Fujian was determined by using the methods of spraying inoculation and natural infection in the field at the stage of corn seedling and adult-plant, respectively. And field experiments were carried out to evaluate the effect of resistant and susceptible corn varieties intercropping on the prevention of the disease. The results showed that the tested corn varieties had different resistance to the population of 301 Cochliobolus heterostrophus isolates. The resistance frequency of corn varieties ranged from 32.23% to 72.76%, with the Rongtian No.1 and Yongzhen No.7 were higher among them. And 11 corn varieties also had different resistance to SCLB in the adult-plant stage, which Rongtian No.1, Yongzhen No.7, and Mingtian No.4 were middle resistance. In addition, inhibition rates to SCLB by Yuetian 22(susceptible corn variety) under intercropping with Rongtian No.1 and Yongzhen No.7(resistant corn varieties) were 33.78% and 25.41%, respectively in Fuzhou. While the disease index decreased by 58.35%, 21.05% and 52.56%, 46.42% respectively in Pingnan with the same treatments during two consecutive years.