应用DNA条形码构建天敌-猎物食物网的方法

The use of DNA barcoding in the establishment of predator-prey food webs

定量构建天敌-猎物食物网是有效开展害虫管理的基础。常用的食物网构建方法有单克隆抗体法、肠道内容物的PCR检测法、实时荧光定量PCR法等。这些方法灵敏度高、特异性强,但只能定性或定量检测天敌对已知猎物物种,即已明确捕食或寄生关系的物种的捕食情况,并不能检测未明确捕食或寄生关系的猎物种类和捕食量。而DNA条形码是一段具有物种特异性的DNA短片段,能够实现物种的快速鉴定。它最早应用于昆虫分类学,现随着高通量测序技术的发展,基于高通量测序的DNA复合条形码技术,对猎物的扩增范围更广,弥补了常规分子方法只能检测已知猎物的缺陷,可实现已知或未知猎物物种的迅速确定,构建相对完整的食物网。为了提高猎物的检测率,完善食物网结构,本文总结了DNA条形码在天敌-猎物昆虫食物网构建中的技术路线,介绍了条形码基因的选择原理、通用引物的设计及验证方法、以及高通量测序及数据分析的基本流程,并以一个实例展示了该方法的实现过程,叙述了该方法的优点及目前存在的争议,旨在为研究基于保护和利用天敌昆虫、增强食物网稳定性的害虫生态调控提供理论指导和方法支持。

Quantitative establishment of predator-prey food web is the foundation of effective pest management.Common methods of establishing food webs include usingmonoclonal antibodies,PCR-based gut content analysis and real-time,fluorescent,quantitative PCR.These methods are highly sensitive and species-specific,but can only qualitatively,or quantitatively,detect known prey or host species.DNA barcoding is a system of species identification using short,species-specific DNA sequences that rapidly identify species and that was first used in insect taxonomy.With the development of high-throughput sequencing technology,DNA metabarcoding based on high-throughput sequencing has a wider range of PCR amplification for prey.Unlike conventional molecular methods,this method is not limited to detecting known prey(or host)species,but can rapidly identify both known,and unknown,prey(or host)species,thereby allowing the construction of relatively complete food webs.This paper summarizes the technological roadmap of using the DNA barcode technique to establish a predator-prey food web.It also introduces the selection principles for barcode genes,design and verification methods of universal primers,as well as the basic flow of high-throughput sequencing and data analysis.The application of the method is illustrated with an example.Finally,we describe the advantages of DNA barcoding and summarize the current controversy over the use of this method.The aim of this paper is to provide theoretical guidance and support for research on the ecological regulation and management of pests based on the protection and utilization of their natural enemies,thereby enhancing the stability of food webs.