| Frankliniella occidentalis (Pergande) is a worldwide pest, and Beauveria bassiana is an important biological agent for control of western flower thrips. The sublethal effect of B. bassiana on F.occidentalis was studied by using two-sex life table. The immune-related genes in F.occidentalis was screened out by comparing the transcriptomes between fungi-treated thrips after 24h/48h/72h and control. Besides that, we also discussed about applications of B. bassiana on F.occidentalis under different temperature. The main results of the paper are as follows:1. Sublethal effects of B.bassiana on life table parameters of F.occidentalis.We assessed effects of parental exposure to Beauveria bassiana on life history traits of subsequent generations of western flower thrips, Frankliniella occidentalis. Progeny from individuals that survived fungal-exposure as second instars, had significantly shorter egg stages, but longer prepupal development times than corresponding untreated controls. However, survivorship to adulthood of these progeny groups did not differ. Although fecundities of the parental types did not differ, the sex ratio of progeny from fungal-treated parents was male-biased whereas sex ratio of progeny from untreated control parents was even. We calculated life table parameters for the progeny and found that all parameters, except for generation time, were significantly less for the progeny of fungal-treated parents than for progeny of untreated parents. The intrinsic rate of increase (r), finite rate of increase (?), net reproductive rate (R0), mean generation time (T) and gross reproductive rate (GRR) were 0.199 d-1, 1.229 d-1,21.84,15.48 d,27.273 respectively for progeny of treated thrips, and 0.266 d-1,1.316 d-1, 52.540,14.92 d,70.64 for progeny of control thrips. Consequently, population projections demonstrated that offspring of parentss exposed to B. bassiana would increase their population more slowly than those from untreated parents. These results demonstrate that B. bassiana has sublethal effects that reduce the reproductive success of F. occidentalis and these effects should be taken into account when evaluating its use in management programs for F. occidentalis.We also simulated control strategy of Beauveria bassiana for the control of western flower thrips. Under 15/20/25/30? temperature, based on the data of thrips population growth rate and infeciency of Beauveria bassiana on western flower thrips, we decided the optimal timing of application and interval.2. Transcriptome analysis of F. occidentalis after infected by B.bassianaIn this study, Second-generation sequencing transcriptome analysis was used in transcriptome analysis of F. occidentalis after infected by B.bassiana at 24/48/72 hpi (hours post infection). Differentially expressed genes (DEGs) and their functions, classifications and signaling pathways were analyzed using bioinformatics tools. This research assembled 41 021 non-redundant Unigenes, with 19 578 Unigenes being annotated by database.1387,1002 and 1960 DEGs was measured at 24hpi,48hpi, 72hpi, respectively. Data showed that 517,367 and 671 DEGs at 24/48/72 hpi were annotated to GO respectively. The Unigenes were mainly enriched in Cellular component of the secondary structure of the notes; cell, "cellular components "and" organelles" had the highest proportion. KEGG pathway analysis indicated that there were 393,187 and 447 differentially expressed genes to match the 126,110 and 133 pathway pathways at 24/48/72 hpi, respectively. The results provide a bioinformatics basis for applying B.bassiana to control F. occidentalis at the molecular level.3. Identification of immune-related genes and qRT-PCR assayBased on the insect immune-related genes already studied, we screened and identified 153 immune-related genes, including 70 Pattern Recognition Protein:12 PGRP,3?GRP,11 CTL,3 galactin, 12 SCRs,19 dacam and 10 Eater; 40 extracellular signal conditioning and amplification genes:10 SP, 30 SPH; 10 signal transduction genes:7 Toll,3 spz; 43 immune response effector:4 Lysozyme,39 POX, 14 SOD,13 catalase,55 Trx,4 TrxR,14 Prx,3 NOS,1 NOX. And the use of real-time quantitative qRT-PCR methods to validate the expression of 15 immune-related genes in expression level, and compared that with the transcriptome data. It showed that these immune-related genes of F. occidentalis plays an important role on defensing the infection of B.bassiana. |
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