Study Of The Functions Of Four Reproductive Related Genes In Phytoseiulus Persimilis By The Technique Of RNAi

Phytoseiulus persimilis is one of the most important biological control agents of spider mites.Multiple studies have been conducted on factors affecting its reproduction,but limited research on related molecular mechanisms have been carried out.In this study,RNA interference of four genes,ribosomal protein Lll(RpLll),ribosomal protein S2(RpS2),transformer-2(tra-2)and Bric-a-brac2(Bob2)to newly emerged females were performed through oral delivery of double-stranded RNA,and knockdown of target genes was verified using qRT-PCR analysis.When RpLll or RpS2 was interfered,42%and 30%P.persimilis individuals became sterile,while the rest had their oviposition duration reduced by 31.8%and 49.9%,fecundity reduced by 48.1%and 67.8%,and egg hatching rate reduced by 20.4%and 22.4%,respectively.In addition,offspring sex ratios were significantly male biased especially at low fecundities.When tra-2 was interfered,no significant differences in fecundity was detected,but egg hatching rate reduced by 30.6%.When Bab2 was successfully interfered,there was no significant change in reproductive parameters,and no significant effect of this gene on the reproduction of females in P.persimilis has been observed.In general,this study verified the possibility of RNA interference in Phytoseiidae through oral delivery,and indicated that RpLll and RpS2 that are involved in egg formation,while tra-2 is involved in embryo development in P.persimilis.Phytoseiid mites might have different sex determination pathways comparing to insects.