抗生素对松毛虫赤眼蜂产雌孤雌生殖品系的影响

Influence of Antibiotics on Thelytokous Strain of Trichogramma dendrolimi

以不同浓度的盐酸四环素饲喂产雌孤雌生殖品系的松毛虫赤眼蜂(Trichogramma dendrolimi),以确定对其体内共生菌Wolbachia的去除效果,探讨松毛虫赤眼蜂生殖适合度受Wolbachia的影响情况。采用不同浓度(5,15,30mg·m L-1)的盐酸四环素连续处理产雌孤雌品系松毛虫赤眼蜂5代,测定其产卵量、羽化率、后代雌性百分率变化。利用Chelex-100法对待测的成蜂进行单头总DNA的提取,以wsp基因专用引物检测蜂体内Wolbachia的去除效果。结果表明:抗生素处理后不同浓度、不同世代处理间羽化率发生显著变化(p<0.05),呈先降低后升高趋势;抗生素处理后产卵量在不同代数间呈无规律变化;后代雌蜂百分比呈现出先降低后增加趋势。高浓度盐酸四环素对Wolbachia的去除效果较好;同一盐酸四环素浓度下不同世代间Wolbachia的去除效果呈现的总体趋势与羽化率类似。研究表明,抗生素确实可去除松毛虫赤眼蜂产雌孤雌品系虫体内的Wolbachi,其去除效果受抗生素处理浓度、处理代数的影响,高浓度抗生素具有较好的去除效果。抗生素可打破松毛虫赤眼蜂产雌孤雌生殖,并影响蜂的羽化率。

Laboratory tests were conducted by feeding Trichogramma dendrolimia adult thelytokous with different concentrations of tetracycline hydrochloride in honey to determine the removal effect of Wolbachia, and explore the Wolbachia influence on adult reproductive fitness. Thelytokous wasps were fed with three tetracycline concentrations（5, 15, 30 mg·m L-1） for five continuous generations, and spawning number, eclosion rate and female offspring percentage were measured. Chelex-100 was used to extract total DNA of the single wasp and Wolbachia molecular identification was conducted for detecting the completely removing of Wolbachia from female adults with the surface of protein-coding genes wsp primers. The results showed that eclosion rate had a significant difference（p0.05）, overall trend of decrease then increase, and spawning number presented irregular change, moreover female offspring percentage showed decrease then increase trend among different generations. After antibiotic treatment with different concentrations, Wolbachia could be effectively removed with high concentration of tetracycline. With the same concentration of tetracycline treatment, the removal efficiency of wolbachia increased at first then decreased. This study suggested that Wolbachia can be removed by antibiotic, different concentrations of antibiotic treatment and processing time both affect Wolbachia removal, high concentration have a remarkable removal efficiency. Antibiotic can break female parthenogenesis and affect eclosion rate.