Resistance Of Aphis Gossypii(Glover)in Xinjiang And Physiological And Biochemical Effects On Cotton Leaves Caused By Insecticide And Aphis Gossypii Stress

In this paper,the third-order relationship of cotton aphid-cotton-insecticide was used as the research system.In view of the scientific problem of insecticide stress and mechanism of induction of plant resistance induced by insecticide stress and A.gossypii feeding,The effects of defense enzyme activity,nutrient,secondary metabolites of cotton leaves by aphids feeding,insecticide alone stress and co-stress with aphids were studied,and studed that the resistance of gossypii in Xinjiang.In order to clarify thatthe influence of chemical control on cotton and A.gossypii,Plants-pests-the interaction of pesticides provides a theoretical basis.The main results are as follows:1.The field population of A.gossypii in all the six regions displayed extremely high resistance to deltamethrin(728-2494 fold),beta-cypermethrin(353?4931 fold)and omethoate(2137?9501 fold).The medium and high resistance was detected to neonicotinoids,resistance ratiosto imidacloprid,acetamiprid and thiamethoxam were 85?412,221?777 and 122?1091,respectively;resistance ratiosto methomyl was 91?292 and carbosulfan of 5.5?148.The medium resistance was detected for both avermectin(20?220 fold)and emamectin benzoate(28?130 fold).2.With the extension of feeding time,the content of soluble sugar in cotton leaves increased and the content of free proline decreased.With the increase of insect density,The content of soluble sugar and free proline increased,and the content of soluble sugar and free proline in cotton leaves was the highest after treatment with 200 heads/plant,which increased by 2.40 times and 1.38 times compared with the control.After different insecticides alone stress(imidacloprid,avermectin,methomyl,deltamethrin and omethoate),and co-stressed,with the extension of stress time and increased concentration of insecticides that the content of soluble sugar and free proline in cotton leaves overall increaseed The effects of 1 mol·L-1,100 mol·L-1 and 1000 mol·L-1 oxydiocarb on soluble sugar content in cotton leaves were higher than other insecticides,which increased by 2.10 times,2.09 times and 2.02 times compared with the control.And 1 mol·L-1,100 mol·L-1 and 1000 mol·L-1 imidacloprid had a great influence on the content of free proline in cotton leaves,which increased by 0.99 times,1.23 times and 1.60 times compared with the control.And the effect of insecticide alone stress on the content of soluble sugar and free proline in cotton leaves was higher than aphids feeding and co-stress with aphids and insecticides(A.gossypii and insecticide).3.With the increase of feeding time and aphid density that the content of tannin and free gossypol in cotton leaves increased,the content of tannin and free gossypol in cotton leaves was the highest after treatment with 200 heads/plant,which increased by 2.08 times and 0.55 times respectively compared with the control.After different insecticides alone stress(imidacloprid,avermectin,methomyl,deltamethrin and omethoate),and co-stressed,the content of condensed tannin and free gossypol in cotton leaves increased or decreased with the increase of stress time and the concentration of insecticide.The effects of 1 mol·L-1,100 mol·L-1 and 1000 mol·L-1 oxydiocarb on tannin content in cotton leaves were higher than other insecticides,which increased by 0.45 times,3.24 times and 6.71 times compared with the control,and the effects of 1 mol·L-1,100 mol·L-1 and 1000 mol·L-1 methomyl on free gossypol content in cotton leaves were higher than other insecticides,which increased by 2.14 times,2.04 times and 0.57 times compared with the control.The effect of co-stress with aphids and insecticides on the content of condensed tannin and free gossypol in cotton leaves was higher than aphids feeding and insecticide alone stress.4.With the extension of feeding time,CAT,POD and PPO activities of cotton leaves treated with 50 head/plant and 100 head/plant increased and then decreased,and after treatment with 200 heads/plant,CAT activity of cotton leaves increased and POD and PPO activity decreased.With the increase of aphid density,the activity of CAT,POD and PPO increased.The activities of CAT,POD and PPO in cotton leaves increased after the different stresses of insecticide,and co-stress of insecticide respectively.Imidacloprid activates CAT activity in cotton leaves,and other insecticides inhibit of CAT activity.