Yang Tingbang, Song Xuhao, Xu Xiaoqin, Zhou Caiquan, Shi Aimin
Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong China.
Institute of Ecology China West Normal University Nanchong China.
Ecol Evol. 2021 Oct 19;11(21):15444-15454. doi: 10.1002/ece3.8252. eCollection 2021 Nov.
As one of the most abundant predators of insects in terrestrial ecosystems, spiders have long received much attention from agricultural scientists and ecologists. Do spiders have a certain controlling effect on the main insect pests of concern in farmland ecosystems? Answering this question requires us to fully understand the prey spectrum of spiders. Next-generation sequencing (NGS) has been successfully employed to analyze spider prey spectra. However, the high sequencing costs make it difficult to analyze the prey spectrum of various spider species with large samples in a given farmland ecosystem. We performed a comparative analysis of the prey spectra of (Araneae, Lycosidae) using NGS with individual and mixed DNA samples to demonstrate which treatment was better for determining the spider prey spectra in the field. We collected spider individuals from tea plantations, and two treatments were then carried out: (1) The DNA was extracted from the spiders individually and then sequenced separately (DESISS) and (2) the DNA was extracted from the spiders individually and then mixed and sequenced (DESIMS). The results showed that the number of prey families obtained by the DESISS treatment was approximately twice that obtained by the DESIMS treatment. Therefore, the DESIMS treatment greatly underestimated the prey composition of the spiders, although its sequencing costs were obviously lower. However, the relative abundance of prey sequences detected in the two treatments was slightly different only at the family level. Therefore, we concluded that if our purpose were to obtain the most accurate prey spectrum of the spiders, the DESISS treatment would be the best choice. However, if our purpose were to obtain only the relative abundance of prey sequences of the spiders, the DESIMS treatment would also be an option. The present study provides an important reference for choosing applicable methods to analyze the prey spectra and food web compositions of animal in ecosystems.
作为陆地生态系统中数量最多的昆虫捕食者之一，蜘蛛长期以来一直备受农业科学家和生态学家的关注。蜘蛛对农田生态系统中主要关注的害虫是否有一定的控制作用？回答这个问题需要我们充分了解蜘蛛的猎物谱。新一代测序（NGS）已成功用于分析蜘蛛猎物谱。然而，高昂的测序成本使得在给定的农田生态系统中难以对大量样本的各种蜘蛛物种的猎物谱进行分析。我们使用个体和混合DNA样本通过NGS对狼蛛科（蜘蛛目，狼蛛科）的猎物谱进行了比较分析，以证明哪种处理方法更适合确定田间蜘蛛的猎物谱。我们从茶园收集蜘蛛个体，然后进行两种处理：（1）从蜘蛛个体中单独提取DNA，然后分别测序（DESISS）；（2）从蜘蛛个体中单独提取DNA，然后混合并测序（DESIMS）。结果表明，DESISS处理获得的猎物科数量约为DESIMS处理的两倍。因此，DESIMS处理大大低估了蜘蛛的猎物组成，尽管其测序成本明显较低。然而，两种处理中检测到的猎物序列的相对丰度仅在科级水平上略有不同。因此，我们得出结论，如果我们的目的是获得最准确的蜘蛛猎物谱，DESISS处理将是最佳选择。然而，如果我们的目的只是获得蜘蛛猎物序列的相对丰度，DESIMS处理也是一种选择。本研究为选择适用方法分析生态系统中动物的猎物谱和食物网组成提供了重要参考。
