Studies On Piriformospora Indica-mediated Rice Resistance To The Brown Planthopper

The development of green prevention,in the course of sustainable development of agricultural,economy and promoting the development of green ecological civilization,promoting the development of green prevention and control technology of crop pests,and promoting the application of microbial pesticides are the scientific problems that national agricultural development needs to face.The interactive study between host plants,insects and rhizospheric microorganisms is an important theoretical basis for the research and development of green control technologies for plant pests,such as the induction and regulation of rhizospheric microorganisms for plant systemic resistance.P.indica a new fungus isolated from Indian desert soil,was found to be non-toxic to humans and animals and safe for the environment.It has been found that P.indica can promote plant growth and development,improve crop yield and quality,and enhance plant resistance to abiotic stress.However,whether it can induce rice resistance to brown planthopper remains to be explored.In this study,we first investigated the effects of rice treated with P.indica on the two-sex life table and population dynamics of brown planthopper,and then measured the effects of rice treated with P.indica on the feeding and oviposition behavior of brown planthopper.Finally,the changes in physiological and biochemical indexes of insect resistance in rice treated with P.indica were measured.The main research results are as follows:The two-sex life table data of brown planthopper in rice treated with P.indica showed that the life history parameters and population parameters of brown planthopper in rice treated with P.indica were significantly higher than that of brown planthopper.The egg production of female planthopper decreased significantly(142.68±7.92 eggs in control group,90.64±2.63 eggs in 5×103cfu/ml treatment group,and 83.20±3.07 eggs in 1×104cfu/ml treatment group).In the treatment group,the value of P.indica 2 ×104cfu/ml was 73.04±3.50 eggs.Population-related parameters such as the intrinsic(rm),the net reproductive rate(R0),and the finite rate of increase(λ)were significantly lower,mean generation time(T)and population doubling time(DT)were significantly extended,population growth and population size was restrained.At the same time,the weight of female brown planthoppers feeding on rice treated with P.indica decreased significantly.The results regarding feeding behavior of brown planthopper on rice treated with P.indica showed that rice treated with P.indica could inhibit brown planthopper feeding.The duration of np,N2 and N3 of rice in P.indica 2×104cfu/ml treatment group was significantly higher than that in control group,and the feeding times of N2 and N3 wave were also significantly higher than that in control group,while the duration of N4-b wave was significantly lower than that in control group.At the same time,the honey dew secretion of rice in the P.indica 2×104cfu/ml group was significantly lower than that in the control group.The third instar nymphs and pregnant female adults of brown planthopper tended to feed on rice in the control group,and the number of eggs of pregnant female adults on rice in the control group was significantly higher than that in the P.indica 2×104cfu/ml group.P.indica can significantly improve the survival rate of rice seedlings under severe infestation by brown planthopper.After the colonization of P.indica,a series of physiological and biochemical indexes in rice were changed.The MDA content of rice in the treatment group was significantly reduced,the POD enzyme activity was significantly higher than that in the control group,and the contents of H2O2,CAT,SOD and GST were not significantly different.