Collaborative Research: Using Herbivorous Insect Genomes for Crop Tracking

这个项目使用昆虫基因组来研究北美原住民扩大作物范围的历史。人类对动植物物种的驯化和辅助传播极大地改变了全球生态系统，但对某些物种历史驯化的直接研究往往受到方法挑战的限制。例如，虽然一些北美作物的祖先范围和后来的范围扩展得到了很好的研究，但其他作物仍然相对难以接近。本研究探讨了寄生在焦点作物上的昆虫基因组中捕获的范围扩展的历史信号是否可以用作植物本身历史的代表。本研究为利用寄生昆虫研究寄主植物的人口统计学历史提供了一般的原理证明，但也特别验证了东方农业综合体（EAC）的三种作物：普通向日葵、耶路撒冷洋蓟和向日葵的驯化前范围和扩张历史的假设。本研究结果为培养研究生与本科生，设计与实施新材料，以进行公共宣传示范，并促成以原住民农业为主题的大型公共科学活动。这项研究利用从特殊昆虫的基因组中获取的信息来重建三种北美作物过去种植和后来范围扩大的特征；这项工作解决了这些问题：这些植物在第一次被用作作物之前生长在哪里，以及它们随后被人类移到哪里（以及何时）？众所周知，普通向日葵、耶路撒冷洋蓟和海苔是北美土著作为东部农业综合体的一部分种植的，但除此之外，对它们各自的祖先范围和后来的范围扩展模式的了解程度存在很大差异。北美Strauzia属的两种蝇类分别以普通向日葵和耶路撒冷洋蓟为食，而细长花蛾的毛虫则是专门以向日葵为食的食草动物。研究人员正在大量收集这三种昆虫寄生虫，它们分布在北美各地的寄主植物中，然后研究它们的基因组，以寻找历史上种群规模变化的信号，以及范围扩张的方向和时间。一般的预测是，每种昆虫遗传多样性最高的区域将对应于EAC的历史边界，这意味着该区域曾是每种植物祖先范围的一部分。第二个期望是，使用遗传数据的人口情景测试将最好地支持相对最近的范围扩展，从各自的原生范围向外辐射。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project uses insect genomes to examine the histories of crop range expansions by Indigenous North Americans. The domestication and assisted dispersal of plant and animal species by humans has dramatically changed global ecosystems, but the direct study of historical domestication of some species is often limited by methodological challenges. For example, while the ancestral ranges and subsequent range extensions of some North American crops are well studied, others remain relatively inaccessible. This research explores whether historical signals of range expansion captured within the genomes of insects, parasitic on focal crop plants, can be used as proxies for the histories of the plants themselves. This research provides a general proof of principle for using parasitic insects to study demographic histories of their plant hosts, but also specifically tests hypotheses for the pre-domestication ranges and histories of expansion for three crops of the Eastern Agricultural Complex (EAC): Common sunflower, Jerusalem artichoke, and sumpweed. This research results in the training of graduate and undergraduate students, lead to design and implementation of new materials for public outreach demonstrations, and bring about a large public science event focused on the Indigenous agriculture.This research uses information captured in the genomes of specialist insects to reconstruct signatures of past cultivation and subsequent range expansions for three North American crops; the work addresses the questions: where did these plants grow before they were first used as crops, and where (and when) were they subsequently moved by people? Common sunflower, Jerusalem artichoke, and sumpweed are known to have been cultivated by Indigenous North Americans as part of the Eastern Agricultural Complex, but beyond this there is great variance in how much is known about their respective ancestral ranges and subsequent patterns of range extensions. Two fly species in the North American genus Strauzia feed on, respectively, common sunflower and Jerusalem artichoke, while caterpillars of the slender flower moth are specialist herbivores on sumpweed. The researchers are making large collections of these three insect parasites from across their host plants’ ranges in the North America, and then interrogating their genomes for signals of historical population size changes and the direction and timing of range expansions. A general prediction is that the region of highest genetic diversity for each insect will correspond to the historical boundaries of the EAC, implicating this area as having been part of the ancestral range for each plant. A second expectation is that tests of demographic scenarios using genetic data will best support relatively recent range expansions, radiating out from their respective native range(s).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.