Characterizing the recruitment nature of weed species

表征杂草物种的补充性质

• 批准号: RGPIN-2015-03939
• 负责人: VanAcker, Rene
• 金额: $ 1.75万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=589483
• 关键词: Characterizing; recruitment; nature; weed; species

The core goal of my research program is to determine how and why weeds emerge when they do. The timing of seedling emergence is a prime determinant of species success and for weeds, the transition from seed to seedling represents a transition from the least to the most vulnerable stage in a plant’s lifecycle. The relative timing (versus crop plants) and the success of weed seedling emergence also determines the competitiveness of weed infestations, the potential for weeds to escape management, and the quantity and quality of weed seeds left to form persistent seed banks. In addition, emergence timing is also a key determinant of the geographic range of species and their invasive potential. Finally, time of emergence greatly impacts the ability of weed species (including escaped crop plants) to survive in unmanaged habitats including roadsides. This has implications for gene flow at the landscape scale and the effective segregation and coexistence of genetically modified (GM) from non-GM crops. Despite its fundamental importance, our understanding of why weeds emerge when they do remains poor. To-date in my program we have been working to document weed emergence timing and to gain deeper insight into the mechanics of emergence timing. Most recently we have shown that timing of flowering and seed shed can play a very significant role in determining what conditions seeds experience (including whether and to what extent they are buried) and that this, in turn, can determine timing of emergence. We use facultative winter annuals (FWA) as model species for this work and with the FWA, Canada fleabane, we were the first to document the effects of these factors (flowering and seed shed timing, and seed depth) on emergence timing. What is not clear is the extent to which observations on one weed species apply to other weed species and to what extent these effects increase fitness of certain individuals thereby impacting population performance (and weediness) in future generations. Our approach over the next 5 years will be to look forward in the life cycle of weeds (flowering timing and seed shed) in order to gain insight looking backward in the life cycle (recruitment and emergence timing) using facultative winter annual weeds as test species. This research will lead to a better understanding of the mechanics of weed emergence timing which in turn will aid weed management, weed risk assessment and the coexistence of GM and non-GM crops.

我的研究计划的核心目标是确定杂草是如何以及为什么在杂草出现时出现的。幼苗出苗的时间是物种成功的主要决定因素，对于杂草来说，从种子到幼苗的过渡代表着植物生命周期中从最不发达阶段到最脆弱阶段的过渡。杂草幼苗出苗的相对时间(与作物相比)和成功与否也决定了杂草侵扰的竞争力、杂草逃脱管理的可能性以及形成持久种子库的杂草种子的数量和质量。此外，羽化时间也是物种地理范围及其入侵潜力的关键决定因素。最后，出苗时间极大地影响杂草物种(包括逃逸的作物)在包括路边在内的无人管理的生境中生存的能力。这对景观尺度上的基因流动以及转基因作物与非转基因作物的有效分离和共存具有重要意义。尽管杂草很重要，但我们对杂草为什么会长出来的理解仍然很差。到目前为止，在我的程序中，我们一直在努力记录杂草的出现时间，并对出现时间的机制有更深入的了解。最近，我们已经证明，开花和种子脱落的时机在决定种子经历什么条件(包括它们是否被埋以及埋到什么程度)方面发挥着非常重要的作用，这反过来又可以决定出苗的时机。我们使用兼性冬季年生植物(FWA)作为这项工作的模式物种，并利用FWA，加拿大灯笼，我们首次记录了这些因素(开花和种子脱落时间，以及种子深度)对出苗时间的影响。目前尚不清楚的是，对一种杂草物种的观察在多大程度上适用于其他杂草物种，以及这些影响在多大程度上增加了某些个体的适合度，从而影响了后代的种群表现(和杂草)。未来5年，我们的方法将是展望杂草的生活史(开花期和种子棚)，以便以兼性冬季一年生杂草为试验物种，回顾生活史(招募和出苗期)以获得洞察力。这项研究将有助于更好地理解杂草出苗时机的机制，这反过来将有助于杂草管理、杂草风险评估以及转基因作物和非转基因作物的共存。