摘要
新近发现重要检疫害虫红棕象甲转移为害本土棕榈树,严重威胁当地农林生态系统。“共生入侵”假说认为入侵害虫与其共生菌(尤其肠道微生物)存在共生关系,驱使着入侵扩散进程。据此,本次以红棕象甲棕榈种群肠道菌为研究对象,通过与原引入的加拿利海枣种群、人工饲料种群的肠道菌数量、组成对比,揭示红棕象甲新种群的肠道菌变化特征。并进一步以纤维素降解菌为检测对象,比较分析不同食源种群的纤维素降解菌功能群差异,及其降解能力。以营养琼脂培养基和羧甲基纤维素钠培养基培养,检查菌落生长,结果发现来自不同食源的红棕象甲肠道菌差异较大:(1)加拿利海枣种群肠道菌丰富度最高,而棕榈种群肠道菌丰富度相比下降了近50%;(2)棕榈种群肠道纤维素降解菌中,缺失一些强降解力菌株(如AM、BR、BS),导致其与加拿利海枣种群相比,降解能力明显下降。而通过形态、理化性状相似性比较,并基于16rDNA序列构建系统发育树,初步鉴定菌株AV(AM)、D(U)、BR分别为Bacillus cereus、Klebsiella variicola、Bacillus pumilus纤维素降解菌。除了食源外,红棕象甲肠道菌也因虫态不同而异,其中成虫肠道菌最丰富,其次为幼虫,而蛹期仅检测到少量菌株。以上结果说明,红棕象甲转移到本土棕榈树为害后,其定殖、建群可能需要经历一个比预期时间更长的适应期才可能稳定。预示红棕象甲侵入新区后,早期防控工作应重视跟踪监测与点上防治的结合,争取在其定殖瓶颈阶段将种群压到最低。
The important quarantine pest,the red palm weevil(RPW),Rhynchophorus ferrugineus Olivier,has been discovered to transfer damaging the native palm plant of Trachycarpus fortune,posing a serious threat to the local agricultural and forestry ecosystem.The“symbiotic invasion”hypothesis suggests that the symbiotic relationship between invasive pests and their symbiotic bacteria(especially gut microbiota)drives the invasion and difusion process.Based on this,this study focused on the gut microbiota of the native palm pest population,by comparing the composition of gut microbiota with the original introduced population in Phoenix canariensis as well as the artificial feeding population,in order to reveal the possible changes in gut microbiota.And we further detected cellulose degrading bacteria,which as the functional group,to compared the difference of abundance as well as the degradation ability among different food-source populations.We cultivated the intestinal bacteria of the RPW using NA culture medium and sodium carboxymethyl cellulose culture medium,and checked the growth of bacteria,it was found that there were significant differences in gut microbiota of RPW among food-source populations.①The intestinal bacteria richness of P.canariensis population was the highest,while that of the native palm population decreased by nearly 50%relatively;②In the gut cellulose degrading bacteria of the native palm population,there were some strong degrading strains(such as AM,BR,BS)missing,resulting in a significant decrease in their degradation ability compared to the original population.By comparing the similarity of morphological and physicochemical traits,and constructing a phylogenetic tree based on 16rDNA sequence,the strains AV(AM),D(U),and BR were preliminarily identified as the following three cellulose degrading bacteria,Bacillus cereus,Klebsiella variicola,and Bacillus pumila.In addition to the food source,the gut microbiota of the RPW also varied depending on the insect stages,and the adults showed the most abundance of gut microbiota,followed by larvae,and only a small number of strains were detected in pupae.The above results indicate that after transferring to the native palm plant in dietary,this invasive pest may require a longer adaptation period than expected before being stable in.colonization.It suggests that after the RPW invades a new area,we should pay attention to combine tracking and monitoring method to prevent and control this invasive pest during early period,and striving to minimize the population size when still being botleneck stage.
作者
李晓媚
周晋民
张弛
张林平
刘兴平
曾菊平
Li Xiaomei;Zhou Jinmin;Zhang Chi;Zhang Linping;Liu Xingping;Zeng Juping(Key Laboratory of Forest Ecosystem Protection and Restoration in Poyang Lake Basin,National Forestry and Grassland Administration,College of Forestry,Jiangxi Agricultural University,Nanchang 330045,China;observation and Research Station of Forestry Ecosystem in Lushan Mountain,Jiujiang 332900,China)
基金
江西省林业科技创新专项(201815)
关键词
入侵害虫
红棕象甲
棕榈
肠道菌
纤维素降解菌
The red palm weevil of Rynchophorus ferrugineus Olivier
Endophytic bacteria
Cellulose degrading bacteria
Invasive pests
Palmaceae
