Comparative Study On Symbiotic Microorganisms In Different Haplotypes Of Laodelphax Striatellus

Laodelphax striatellus belongs to the order Hemiptera,Planthopper family,and it is widely distributed in the world.Laodelphax striatellus sucks rice juice and spreads various virus diseases.It is an important rice pest and seriously affects rice in our country.Various studies have pointed out that the microbial community plays an important role in the host’s digestion,immunity,behavior,etc,affecting the host’s health.However,the mechanism of the effect on the microbial structure in insects is still unclear.Mitochondria,as the "energy factory" of organisms,are the main places for ATP synthesis.It has been found that the variation of mitochondrial DNA can affect the efficiency of ATP synthesis,and then affect the biological characteristics of organisms,and whether it can also affect the microbial community structure is still unknown.This study conducted population genetic analysis of Laodelphax striatellus microbial structure in vivo through mitochondrial ND2 gene and 16 S rRNA gene sequencing,explored the relationship between Laodelphax striatellus mitochondrial variation and microbial communities from 10 geographic populations in China and 6 geographic populations in Japan.The results are as follow :(1)Population genetic diversity: The mitochondrial ND2 genes of 226 Laodelphax striatellus from 16 populations were amplified and sequenced.There are 32 mitochondrial haplotypes which were divided into C and T groups.The haplotype diversity is 0.761,and the nucleotide diversity is 0.00361.The Hokkaido population has the highest nucleotide diversity and haplotype diversity,and the genetic diversity is high.The haplotype and nucleotide diversity of the Jang Yan population are both 0,and the population genetic diversity is lacking.The Fst results show that there is a strong genetic differentiation between the Yan Shou,Fukuoka,Yan Ji populations and other populations.The Fst values between the Kagoshima population and other populations are negative,the gene flow among populations was strong.Analysis of molecular variance(AMOVA)showed that the variation of the population mainly comed from within the population.(2)Diversity of microbial structure: Through amplifying the V3-V4 region of Laodelphax striatellus 16 S by high-throughput sequencing,we study the differences in microbial structure of different geographic populations.The analysis at the genus level shows that Wolbachia is in a dominant position among most geographic populations,and the gray planthopper in China With the increase of latitude,the infection abundance of Wolbachia tends to increase,There were significant differences among most paired populations.The Alpha diversity and Beta diversity among all populations are compared and there are differences in species and abundance of microorganisms between different geographic populations.The Shannon indexes of Niigata population,Dong Hai and Jang Yan population are relatively high,therefore their community diversity is high.The shannon index of the Saitama population is 0.166 and the simpson index is 0.064,which means that the community diversity is poor.(3)The relationship between microbes and mitochondrial haplotypes:According to previous research,we divided the collected Laodelphax striatellus into two mitochondrial haplotypes,HGI and HGII.The shannon index of HGI type(C)Laodelphax striatellus is1.0637,and the shannon index of HGII type(T)Laodelphax striatellus is 0.24813.There is a difference between them.The simpson index of the C haplotype Laodelphax striatellus is0.57667,and the simpson index of the T haplotype Laodelphax striatellus is 0.73925.The difference is significant.The Wolbachia abundance between the two haplotypes is not significantly different.The abundance among Rheinheimera,Pseudomonas,and Exiguobacterium is of a significant difference.The difference of the content of these three bacteria may be closely related to the mitochondrial haplotype.42 OTU biomarkers are calculated by random forest algorithm to distinguish the two haplotypes.In this paper,we studied the genetic structure diversity and microbial diversity of different geographical populations of Laodelphax striatellus,and explored the differences of microbial structure of different mitochondrial haplotypes,so as to provide a theoretical basis for the interaction between host genetic structure and microorganisms.