High Temperature And Antibiotics Modify Reproduction Of Wolbachia-infected Trichogramma Pretiosum

Trichogramma pretiosum(Hymenoptera: Trichogrammatidae) is an important natural enemy of many Lepidopterous pests in agricultural and forest areas. Wolbachia is an obligate intracellular symbiotic bacteria, which causes the parthenogenesis in T. pretiosum.The reproduction modifing of Wolbachia-infected T. pretiosum reared under the high temperature(30?) and treated with four antibiotics, tetracycline hydrochloride, rifampicin,gentamicin and penicillin were investigated in the present study. Results are showed as follows:1. According to the phylogeny of Wolbachia Surface Protein(wsp)sequences,Wolbachia from T. pretiosum and their host month, Corcyra cephalonica(Stainton), were classed into Kay subgroup and Pip subgroup of B group, repectively. Wolbachia-infected theltokous wasps exhibited sexually aberrant when be reared at high temperatures(30?) or treated with these four antibiotics. Male and other ten intersex morphotypes offsprings were observed from the F0 generation. Meanwhile, the shapes of ovrioles became smaller and the eggs in ovrioles were reduced. High temperature(30?), three contents of four antibiotics were used to try to eliminate Wolbachia from wasps and their toxic effects to the wasps were invested. Results showed that Wolbachia can't be depleted by rearing in high temperature or treatment with these four antibiotics. Moreover, high contents of antibiotics(50 mg/m L, 100mg/m L) will kill wasps. I also detected the number of parasitized eggs and sex ratios of offsprings of Wolbachia-infected wasps when they were reared in 30? and treated with antibiotics. Results showed that ratios of male were higher by antibiotic treatments than those of by high temperature treatment. Increasing by the contents of antibiotics, mean number of parasitized eggs were decreased.2. Bacterial density of sexually aberrant morphtypes 3, 4 and 5 and female samples from F0 to F3 generations rearing in high temperature treatment, was estimated by assessing thecopy number of the wsp gene form Wolbachia using real-time quantitative PCR(RT-q PCR).Analysis revealed no significant difference among these sexually aberrant morphtypes, where as with a continuous decrease of the symbionts by the increasing generations treated by antibiotics.3. Total 31439 unigenes, in which 29439 belong to 25 function classes and 10316 belong to 183 passways were annotated by transcriptome analysis. These data will inprove our research on the Wolbachia manipulation of reproduction of T. pretiosum. Moreover, 9749 sample sequences repeats(SSR)detected from transcriptome analysis will provide molecular markers for population genetics and diversity research of T. pretiosum.