Study On Decoyinine-Mediated Rice Resistance To Nilaparvata Lugens

The development of eco-friendly prevention and control technology is an important mean to achieve sustainable agricultural development and promote ecological civilization and green development.Decoyinine(DCY)is a secondary metabolite isolated from Streptomyces hygroscopicus,which has been found to stimulate crop growth,promote plant tissue formation,regeneration of plant damaged tissues and enhance rice resistance to Nilaparvata lugens.Previous study has explored the effect of DCY immersion treatment on BPH of susceptible rice variety TN1,but did not explore the effect of DCY on field-promoted rice varieties,Therefore,this study explored the effects of different DCY-treated rice varieties on the parameters of the two-sex life table and population parameters,oviposition preference,and feeding behavior of BPH,qRT-PCR was used to determine the effect of DCY-treated rice varieties on the expressions of reproduction-related genes in BPH.Provide theoretical basis for exploring the enhancement of rice insect resistance by DCY.The main findings are as follows:1 Effects of different rice varieties treated with DCY on life table parameters of Nilaparvata lugensThe life history parameters and population parameters of different varieties of rice treated with DCY were significantly changed,and the egg production of female BPH in each treatment group decreased significantly.There were differences in the adult life span of male and female BPH on the Liangyou 566 species,and a high concentration of DCY treatment would lead to a shortening of the adult life cycle of male and female BPH;On the Nanjing 9108,the lifespan of BPH treated with different concentrations of DCY was lower than that of the control group.The total nymphal development period of BPH was significantly shortened after feeding on the Xiangliangyou 900,while the total nymphal development period of BPH that fed Xudao 10 was prolonged.The population life table parameters of three species,namely Liangyou 566,Nanjing 9108,and Xudao 10,such as the intrinsic rate of increase rm,the net reproductive rate R0 and the finite rate of increase λ,decreased significantly,while the mean generation time T and the doubling time DT increased significantly;There was no difference in the population life table parameters of BPH on Xiangliangyou 900.Using Timing-MSChart software to simulate population dynamics,comparing the population growth maps of the four species,it was found that after 60 days of development,there was no difference in the population growth of BPH on Xiangliangyou 900,and there were significant differences in the other three species.2 Effects of different rice varieties treated with DCY on feeding behaviors and reproduction-related gene expression of Nilaparvata lugensOviposition preference experiments showed that BPH preferred to lay eggs on rice without DCY treatment,and the weight of female planthoppers and honeydew decreased significantly in eating DCY-treated rice.The transcriptional expression levels of NlVg and NlVgR were measured by taking the ovaries of female adults of BPH that fed on untreated or DCY100-treated rice for 1,3,5,and 7 days,and the experimental results showed that DCY-treated rice could significantly inhibit the expressions of NlVg,resulting in delayed ovarian development and decreased egg-laying capacity of BPH.