Three Insecticides On Two-way Effect Of Cold Rice And Oulema Oryzae

With the increasing growing area of rice in Heilongjiang Province, the extent and damage of oulema oryzae are increase year by year, which has become the main limitation factor for rice production in recent years.Currently,pesticide chemical control is still the main method that prevent oulema oryzae.Chemical control bring about some negative effects such as pesticide residues,environmental pollution and pest resurgence for a long time.Therefore,we study the two-way change of rice physiological indices and protective enzymes and detoxification enzymes in oulema oryzae under the using of pesticide,which can reveal the physiological mechanism of oulema oryzae in resurgence and provide the theoretical basis of comprehensive treatment to oulema oryzae.1.In this study, we research the change of rice physiological indices under the using of pesticides and determine the change of chlorophyll content, soluble sugar content, protein content, free proline and protective enzymes content with time in resistant varieties and susceptible varieties.With the using of three pesticides ,the results show that chlorophyll content is lower than the control in the susceptible varieties and chlorophyll content show greater fluctuation in the resistant varieties;The change trend of MDA activity is higher than control in the susceptible varieties and opposite in the resistant varieties; Soluble sugar content is lower than the control in the susceptible varieties and soluble sugar content is higher than control in the resistant varieties; Free proline content markedly is higher than control in the susceptible varieties and free proline content is lower than the control in the resistant varieties; Protein content is little lower than the control in the susceptible varieties and protein content is little higher than control in the resistant varieties.The activity of three kinds of protective enzymes change different in every kinds of species with the using of different pesticides. POD activity increased at first and then declined in the resistant varieties and susceptible varieties. POD activity is higher than control in the susceptible varieties treated with cypermethrin and imidacloprid. POD activity is higher than control in the susceptible varieties treated with abamectin in the first day, fourth day and fifteenth day and is lower than control in the ninth day; POD activity is lower than control in the resistant varieties treated with cypermethrin and imidacloprid in the first day, fourth day and fifteenth day and is higher than control in the ninth day, POD activity is higher than control in the resistant varieties treated with abamectin in the first day, fourth day and ninth day and is lower than control in the fifteenth day.SOD activity first increased and then decreased before rising again treated with three pesticides, SOD activity is higher than control in the susceptible varieties treated with cypermethrin only in the first day, SOD activity is higher than control in the susceptible varieties treated with imidacloprid in the first day and fourth day and is lower than control in the ninth day and fifteenth day; SOD activity is higher than control in the resistant varieties treated with three pesticidesin the first day and fourth day and is lower than control in the ninth day and fifteenth day;CAT activity Decreased gradually treated with three pesticides in the susceptible varieties varieties and little change in the resistant varieties.CAT activity is lower than control in the susceptible varieties treated with three pesticidesin;CAT activity is lower than control in the resistant varieties treated with cypermethrin only in the first day.CAT activity is lower than control in the resistant varieties treated with imidacloprid and abamectin in the first day, fourth day and ninth day and is higher than control in the fifteenth day.2.With oulema oryzae as the research object, we research the change of peroxidase, superoxide dismutase, glutathione s-ransferase and carboxylesterase content in the oulema oryzae under the using of three pesticides and analyze physiological response situation of oulema oryzae under the using of pesticides.With the using of three pesticides ,the results show that protective enzymes change in the same trend in the larvae and adults of oulema oryzae and the content is higher than control. Detoxification enzymes in the larvae of oulema oryzae show greater fluctuation.carE activity in the larvae of oulema oryzae is higher than control treated with cypermethrin in the first day, fourth day and fifteenth day and is lower than control in the ninth day. CarE activity in the larvae of oulema oryzae is higher than control treated with imidacloprid and abamectin.GSTs activity in the larvae of oulema oryzae is lower than control treated with cypermethrin in the first day, ninth day and fifteenth day and is higher than control in the fourth day. GSTs activity in the larvae of oulema oryzae is lower than control treated with imidacloprid and abamectin in the first day and ninth day and is higher than control in the fourth day and fifteenth day. GSTs activity in the adults of oulema oryzae is higher than control during the entire spraying.3.By the comparative analysis,we find that three pesticides differently restrain the synthesis of chlorophyll in the susceptible varieties and synthesis of chlorophyll in the resistant varieties is affected in early and little effect in the medium spraying. three pesticides promote the synthesis of MDA in the susceptible varieties and restrain in the resistant varieties. Decrease of chlorophyll and increase of MDA reduce the resistance of rice; Decrease of soluble sugar and increase of free proline reduce the resistance of rice and increase the attraction of pests; Three pesticides differently restrain the synthesis of protein in the susceptible varieties and reduce the resistance of rice and have little effect of protein synthesis in the resistant varieties. Three pesticides differently restrain the activity of protective enzymes.The enzyme of POD and SOD after a brief rise in the stress response is a decline in resistance under the using of pesticides.The decrease of protective enzymes reduce the resistance to the the larvae of oulema oryzae;After feeding on three pharmacy rice, protective enzymes and detoxification enzymes in the larvae and adults of oulema oryzae are differently increased,which show that resistance and detoxification of oulema oryzae are strong and it is conducive to feeding on rice.The effect of three insecticides on rice and oulema oryzae is different. The cypermethrin has strong efficacy in the early time and short persistence and is easy to make resistant to oulema oryzae, followed by imidacloprid. Abamectin has a long efficacy to rice and oulema oryzae.