辐照对瓜实蝇遗传区性品系成虫肠道菌的影响及优势菌的利用研究初探

发布时间：2019-01-09 06:13

【摘要】：瓜实蝇Bactrocera cucurbitae(Coquillett)是重要的农业害虫,生物防治实蝇技术—昆虫不育技术[Sterile Insect Technique(SIT)]已越来越受到国内外农业专家的青睐,而SIT中的辐照过程削弱了靶标实蝇的体质健康,关于这一方面的研究还鲜少有详细的报道,本文研究了辐照对瓜实蝇遗传区性品系[B.cucurbitae genetic sexing strain(GSS)]肠道菌的多样性和相对丰度的影响,并分离、鉴定和筛选优势菌属饲喂虫源,在一定程度上降低了辐照的伤害。研究结果如下:1、以100Gy137Cs辐照瓜实蝇遗传区性品系的5、8、11和13日龄的雌、雄成虫,并采用基于16SrDNA的IlluminaMiSeq测序技术分别对其肠道菌群进行测序分析。结果表明从瓜实蝇雌、雄成虫肠道中共检测到4个菌门和19个主要菌属,其中变形菌门Proteobacteria(占总量的50%～98%)、厚壁菌门Firmicutes(占总量的2%～47%)和普罗威登斯菌属Providencia sp.、肠杆菌属Enterobacter sp.分别是瓜实蝇GSS肠道中的优势菌门和菌属;辐照显著的减少了肠道中的微生物多样性,降低了优势菌属的相对丰度,这与瓜实蝇的性别和成虫日龄无关。2、利用传统的微生物分离技术从瓜实蝇雌、雄5日龄成虫肠道中共分离得到7种菌属,分别为:肠杆菌属(37%),普罗威登斯菌属(18.5%),克雷伯氏菌属Klebsiella sp.(1.9%),芽孢杆菌属Lysinibacillus sp.(1.9%),西地西菌属 Cedecea sp.(24%),Bacterium sp.(11.1%)和未知属名的其他菌属other(5.6%)。3、利用肠杆菌属作为瓜实蝇GSS幼虫饲料的添加剂,用活菌(PI)、死菌(API)分别作为两个处理组,用无菌(NPI)作为对照,饲喂寄主至化蛹后,分别测定瓜实蝇GSS的生物学和形态学指标,结果发现活菌组能显著的增加瓜实蝇GSS的蛹重、头宽和胸长,而死菌和活菌组都能显著的提高雌、雄成虫的耐压存活率,它们提高的平均百分比分别是18%和4.72%(雌虫),15%和11%(雄虫)。因肠杆菌属易分离和培养,在所分离的菌属中所占比例最大,而应用肠杆菌属优化幼虫饲料有显著的效果,结果证明肠杆菌属是瓜实蝇GSS肠道中的优势菌属,也是强化幼虫饲料的益生菌属。本研究成果将为未来开发利用营养菌作为瓜实蝇GSS幼虫饲料的添加剂,从而在一定程度上修复辐照的损伤提供理论依据,以期提高不育成虫的质量,为能高效的应用SIT技术打下基础。
[Abstract]:Bactrocera cucurbitae (Coquillett) is an important agricultural pest. Biological control technology of fly, insect sterility technique [Sterile Insect Technique (SIT)] has been more and more favored by agricultural experts at home and abroad. However, the irradiation process in SIT weakens the physical health of the target fly, and there are few detailed reports on this aspect. The effects of irradiation on the diversity and relative abundance of intestinal bacteria in the genetic line [B.cucurbitae genetic sexing strain (GSS)] of melon fruit fly were studied, and the dominant bacteria were isolated, identified and screened, which reduced the damage caused by irradiation to some extent. The results were as follows: 1. 100Gy137Cs was used to irradiate the female, male and male adults of 5, 811 and 13 day old female and male adults of genetic region of fruit fly, and the intestinal flora was sequenced by IlluminaMiSeq sequencing technique based on 16SrDNA. The results showed that there were 4 phylum and 19 main genera in the intestinal tract of female and male adults of fruit fly, among which Proteobacteria was 50%. Firmicutes (2 / 47% of total) and Providencia sp., (Enterobacter sp.) It is the dominant phylum and genus in GSS intestinal tract of fruit fly, respectively. Irradiation significantly reduced the microbial diversity in the intestine and the relative abundance of the dominant genus, which had nothing to do with the sex of the fruit fly and the age of the adult. 2. The traditional microbiological isolation technique was used to isolate the female from the fruit fly. Seven species of bacteria were isolated from the intestinal tract of male adults at 5 days of age. They were Enterobacter (37%), Providence (18.5%), Klebsiella (1.9%) and Bacillus (Lysinibacillus sp. (1.9%). Cedecea sp. (24%), Bacterium sp. (11. 1%) and other unknown genus other (5. 6%). 3. Enterobacter was used as additive for GSS larvae of fruit fly and (PI), was used as a living bacterium. Dead bacteria (API) was used as two treatment groups, and sterile (NPI) was used as control. After feeding host to pupa, the biological and morphological indexes of GSS were measured respectively. The results showed that the live bacteria group could significantly increase the pupae weight of GSS. The head width and chest length were significantly increased in both dead and living bacteria groups, and the average percentage of increase was 18% and 4.72% (female), 15% and 11% (male), respectively. Because Enterobacterium is easy to isolate and culture, it accounts for the largest proportion in the isolated genus, and the application of Enterobacter to optimize larval feed has remarkable effect. The results show that Enterobacter is the dominant genus in the intestinal tract of GSS. It is also a probiotic genus that strengthens larval feed. The results of this study will provide a theoretical basis for the future development and utilization of nutritious bacteria as a feed additive for GSS larvae of fruit flies, thus repairing the damage caused by irradiation to a certain extent, in order to improve the quality of sterile adults. It lays the foundation for the efficient application of SIT technology.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S433

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