棉花单宁-黄酮类化合物对棉铃虫的抗性潜力

Potential resistance of tannins-flavoniods in upland cotton against Helicpverpa armigera (Hübner)

陆地棉棉叶甲醇提取物包含了棉花的大部分单宁 -黄酮类化合物。这些化合物对棉花多种病虫害具有抗性作用。将这些化合物定量加入人工饲料中饲养棉铃虫 1龄幼虫 5d,结果表明 ,儿茶素、缩合单宁、芸香苷和异槲皮苷在饲料中的浓度增加均与幼虫体重生长呈显著负相关 ,ED50 分别为 0 .81 % ,0 .4 9% ,0 .57%和 0 .83% ;儿茶素则不存在这种关系 ;用含 0 .8%的浓度儿茶素、缩合单宁、芸香苷和异槲皮苷的饲料测试棉铃虫 ,发现随取食量的增加 ,相对生长率的增加显著低于对照 (不含次生物质 ) ,即这些物质属于慢毒剂 ;而儿茶素仅有阻食作用。

Cotton tannins flavoniods are important compounds associating with the host plant resistant to insect pests and diseases including Heliothis sp. and Helicoverpa sp.. The dosage responses on H. armigera larvae of different compounds are tested. After the 1st instar larvae fed 5 days on the diets contained compounds, the ED 50 of larvae on gallocatechin, condensed tannins, rutin and isoquercitrin were 0 81%, 0 49%, 0 57% and 0.83% respectively. The results indicated that there were significantly negative correlation between the concentration of these compounds and the body weight of larvae. But there was irrelevant between concentration of catechin and larvae body weight.The increase of relative larval growth rate was significantly lower than that of the control as the increase of larval feeding amount on the diet separately contained 0.8% gallocatechin, condensed tannins, rutin and isoquercitrin. The results indicated that these compounds are chronic toxins.