NSF-DEB-RAPID: Evolution of reproductive barriers in long-lived conifers

了解物种形成的机制是进化生物学的一个基本目标，对在快速变化的景观中保护和物种管理具有直接意义。这项研究旨在了解世界上最稀有的松树之一，长寿命针叶树Torrey Pine的繁殖障碍是如何进化的。该研究仅局限于两个离散的种群，一个大陆种群和一个岛屿种群，该研究使用了一种特别令人兴奋的方法，通过在共同环境中对植物表型和适应性特征的纵向监测，来了解长寿物种的生殖障碍进化。2007年，在圣巴巴拉植物园，大陆、岛屿和第一代杂交幼苗被种植在一个共同的环境中，这些幼苗代表了由大陆花粉供体受精的岛屿母株。对这些树的年度监测表明，在普通环境中作为杂交品种有一个优势，杂交品种相对于母树更高，表现出更高的繁殖力。然而，这种优势是否在后代中保持仍然是一个问题，这将有助于深入了解导致生殖隔离的机制。这项研究将研究那些定义物种的因素，并将对稀有和特有物种的保护和管理产生影响。这个项目将为本科生和研究生提供实地和数据库管理的机会。此外，该项目将汇集来自政府（USDA-Forest Service）、非政府（Santa Barbara Botanic Garden）和研究机构的合作伙伴，以促进这些具有基本科学和应用保护价值以及教育影响的遗传资源的长期保存。这个RAPID项目将资助对Torrey Pine （Pinus torreyana）进行长期种源试验的数据和组织收集，Torrey Pine是一种稀有的加州特有针叶树，种植在加利福尼亚州圣巴巴拉市的圣巴巴拉植物园。该项目的目标将是(i)收集球果，以便在加利福尼亚州Placerville的森林遗传学研究所的一个集装箱公共花园中进行加工和种植；（ii）收集针叶组织，用于长期储存和基因组学工作；（iii）评估性状和形态数据，以便将来与基因组数据进行关联分析。普通花园物业可能很快就会挂牌出售，这可能会限制进入大陆、岛屿和2007年建立的F1个体，这些个体现在只繁殖并生产F2代。因此，这笔资金为长期的托里松项目的发展提供了取样组织和收集数据的机会，该项目旨在了解长寿针叶树种群差异进化的基因组和表型结构。

Understanding the mechanisms underlying speciation is a fundamental aim of evolutionary biology with direct implications to conservation and species management in a rapidly changing landscape. This research aims to understand how barriers to reproduction have evolved in a long-lived conifer, Torrey Pine, one of the rarest pines in the world. With a restricted distribution to just two discrete populations, a mainland population and an island population, this research uses a particularly exciting approach to understand the evolution of reproductive barriers in a long-lived species using longitudinal monitoring of plant phenotypes and fitness characteristics within a common environment. Established in 2007, mainland, island and first-generation hybrid seedlings representing island maternal plants fertilized by mainland pollen donors were planted into a single common environment at the Santa Barbara Botanic Garden. Annual monitoring of these trees suggests there is an advantage to being a hybrid in the common environment, with hybrids taller and exhibiting increased fecundity relative to parent trees. However, whether this advantage is maintained across future generations remains a question, which will provide insight into mechanisms that contribute to reproductive isolation. This research will study those factors that define a species, and will have conservation and management implications for rare, endemic species. This project will provide field and database management exposure for students at the undergraduate and graduate level. In addition, this project will bring together partners from governmental (USDA-Forest Service), non-governmental (Santa Barbara Botanic Garden) and research institutions to promote the long-term preservation of these genetic resources, which have fundamental scientific and applied conservation value, and educational impact.This RAPID project will fund a collection of data and tissue from a long-term provenance trial of Torrey Pine (Pinus torreyana), a rare, endemic California conifer planted at the Santa Barbara Botanic Garden in Santa Barbara, California. The objectives of the project will be to (i) collect cones for processing and planting within a containerized common garden at the Institute of Forest Genetics in Placerville, CA, (ii) collect needle tissue for long-term storage and genomics work, and (iii) assess trait and morphological data for future association analyses with genomic data. The common garden property may be listed for sale shortly, which could restrict access to the mainland, island, and F1 individuals that were established in 2007 and that are only now reproductive and producing an F2 generation. Therefore, this funding provides an opportunity to sample tissue and collect data for the development of a longer term Torrey pine project which will aim to understand the genomic and phenotypic architecture underlying the evolution of population differences in a long-lived conifer.