取食非靶标植物对莲草直胸跳甲消化酶活力的影响

Effects of Feeding Non-target Plants on Digestive Enzymes Activity of Agasicles hygrophila

莲草直胸跳甲是入侵杂草喜旱莲子草的专食性天敌,为探究莲草直胸跳甲无法在非靶标植物正常完成生活史的原因,将消化酶作为研究的出发点,探究了莲草直胸跳甲取食喜旱莲子草、莲子草、莙荙、甜菜后体内消化酶活性的变化,同时对比了4种植物的营养物质、次生代谢物质及含水量。结果表明,饥饿时蛋白酶和淀粉酶活力均有提升,取食莲子草以及莙荙对莲草直胸跳甲成虫的蛋白酶活力影响较大;取食甜菜可以提高淀粉酶活力;取食甜菜和莙荙时,纤维素酶活力提升;不同植物中可溶性糖含量最高的是甜菜;含水量、可溶性蛋白以及单宁含量最高的是莙荙,与喜旱莲子草均存在显著差异。相对于寄主植物喜旱莲子草,莲草直胸跳甲在取食非寄主植物时,消化酶活力变化明显,表明莲草直胸跳甲对非靶标植物不太适应。

Agasicles hygrophila is a natural enemy of the invasive weed Alternanthera philoxeroides.To explore the reason why Agasicles hygrophila could not complete its life history normally in non-target plants,this study took digestive enzymes as the starting point of the research for studying host specificity,and explored the changes of digestive enzyme activities of Agasicles hygrophila,after starvation or feeding on Alternanthera philoxeroides,Alternanthera,Beta vulgaris and Beta vulgaris var.cicla for 12,24,48,96 h,respectively.At the same time,nutrients,secondary metabolites and water content of the four plants were compared.The result showed that feeding on Alternanthera philoxeroides and Beta vulgaris var.cicla had a greater impact on the protease activity of adults of Alternanthera philoxeroides.Feeding on Beta vulgaris increased amylase activity.When feeding Beta vulgaris and Beta vulgaris var.cicla,the cellulase activity increased.Among different host plants,Beta vulgaris had the highest content of soluble sugar,whereas Beta vulgaris var.cicla had the highest water content,soluble protein and tannin content.The study showed that compared with the host plant Alternanthera philoxeroides,the digestive enzyme activity of Alternanthera philoxeroides changed obviously when feeded on non-host plants,also showed that it had the best adaptability to host plants.