不同玉米品种对玉米蚜的抗性及其与瓢虫的联合控害作用

Resistance to corn aphid(Rhopalosiphum maidis Fitch) of different corn varieties(lines)and its association with predator ladybirds in controlling aphid population

调查了26个玉米品种(系)在云南昭通地区的玉米蚜及其捕食型天敌瓢虫的发生情况,采用蚜量比值法比较了玉米品种在田间对玉米蚜的抗性,并分析了不同玉米品种的抗蚜性与益害比(瓢虫/玉米蚜)的关系。结果表明:在田间自然感蚜条件下,高抗品种有9个,分别为路单15号、胜玉6号、云瑞62、靖单11号、云瑞339、云瑞407、云瑞668、云瑞89、云瑞7号;抗性品种6个,分别为云瑞392、云瑞222、临玉9号、云瑞999、云瑞10号、云瑞505;中抗品种1个,为珍禾99;感蚜品种4个,分别为云瑞666、足单808、宣黄单5号、临玉8号;高感品种6个,分别为临玉10号(白粒)、大天一号、海玉92、宣黄单2号、云瑞108、师单4号。不同玉米品种的抗蚜性与益害比有显著的正相关性,益害比与蚜量比值呈幂函数关系,说明玉米的抗蚜性与瓢虫对玉米蚜有明显的联合控制作用。

The dynamics of corn aphid（ Rhopalosiphum maidis Fitch） and predator ladybirds in 26 corn varieties（ lines） were systematically investigated in Zhaotong,Yunnan Province,to compare their resistance to aphid among varieties in corn field by using the methods of aphid number ratio,and to study the relationship between resistance and the population ratio of ladybirds to aphid in different corn varieties. The results indicated that there were 9 highly resistant varieties（ Ludan 15,Shengyu 6,Yunrui 62,Jingdan 11,Yunrui 339,Yunrui 407,Yunrui 668,Yunrui89,Yunrui 7）,6 resistant varieties（ Yunrui 392,Yunrui 222,Linyu 9,Yunrui 999,Yunrui 10,Yunrui 505）,1moderately resistant varieties（ Zhenhe 99）,4 susceptible varieties（ Yunrui 666,Zudan 808,Xuanhuangdan 5,Linyu 8）,and 6 highly susceptible varieties [Linyu 10（ white）,Datian 1,Haiyu 92,Xuanhuangdan 2,Yunrui108,Shidan 4]. Among the above 26 varieties,the variety with high resistance tended to have high ratio of ladybirds to corn aphid,and a power function was regressed between the ratio value of aphid and the ratio value of ratio of ladybirds to corn aphid,implying an association of resistance of corn with predator ladybirds in controlling aphid popula-tion in field.