不同苜蓿品种对豌豆蚜中肠消化酶活性的影响

摘要

为了探究取食苜蓿对豌豆蚜中肠消化酶的影响，揭示苜蓿抗蚜的生化机制，本文测定了2种色型豌豆蚜取食8个不同抗性苜蓿品种后中肠主要消化酶的活性。结果表明，红色型豌豆蚜在取食低抗品种渭南后，其中肠蛋白酶活性为（9．71±0．63）U／mL，绿色型豌豆蚜取食感虫品种猎人河后为（9．88±0．56）U／mL，二者取食高抗品种三得利后分别为（0．33±0．10）U／mL 和（0．43±0．02）U／mL；红色型豌豆蚜取食感虫品种猎人河后其中肠脂肪酶活性为（4．12±0．30）U／mL，绿色型豌豆蚜则在取食低抗品种渭南后酶活达（4．00±0．29）U／mL，二者脂肪酶活性在取食高抗品种甘农5号后分别为（1．63±0．10）U／mL 和（1．08±0．13）U／mL；2种色型的豌豆蚜中肠淀粉酶的活性在取食感虫品种猎人河后分别为（2．30±0．40）U／mL、（2．14±0．29）U／mL。此外，豌豆蚜取食8个苜蓿品种后，红、绿色型豌豆蚜的蛋白酶、脂肪酶及绿色型豌豆蚜的淀粉酶活性与苜蓿抗性间均呈高度负线性相关，表明苜蓿品种的抗蚜性越高，蚜虫取食后其中肠3种酶的活性越低，抗性苜蓿品种主要抑制豌豆蚜中肠消化酶的活性。%This research measured the midgut protease enzyme activity in the red and green pea aphid (Acyrtho-siphon pisum )after they had fed on 8 alfalfa (Medicago sativa )varieties with differing resistance.The midgut protease activity of the red pea aphid was (9.71 ±0.63)U/mL after they had fed on the variety Weinan,and was (0.33 ±0.10)U/mL after feeding on variety Sandili.The protease activity of the green pea aphid was (9.88±0.56)U/mL after feeding on the variety Hunter river,and (0.43±0.02)U/mL after feeding on Sand-ili.The midgut lipase activity of the red pea aphid was (4.12 ±0.30)U/mL when they infested the cultivar Hunter river,but was only (1.63±0.10)U/mL (P <0.05)when they infested the variety Gannong No.5.Li-pase activity was (4.00 ±0.29 )U/mL when aphids had fed on the variety Weinan,and was (1.08 ±0.13 ) U/mL when feeding on the cultivar Gannong No.5.The midgut amylase activities of the red and green pea a-phids were (2.30 ±0.40)U/mL and (2.14 ±0.29 )U/mL,respectively when they had fed on the cultivar Hunter river.In summary,for pea aphid infestation of 8 alfalfa varieties with differing aphid resistance,a high negative linear correlation was observed between the resistance of the different alfalfa varieties and the prote-ase,lipase and amylase activities of the pea aphid,i.e.when the alfalfa aphid resistance is higher,the enzyme activity is lower.Hence it is concluded that the resistant alfalfa varieties restrict the midgut digestive enzyme activity of the pea aphid.