Importance of whole-plant biomass allocation and reproductive timing to habitat differentiation across the North American sunflowers

Background and Aims: Trait-based plant ecology attempts to use small numbers of functional traits to predict plant ecological strategies. However, a major gap exists between our understanding of organ-level ecophysiological traits and our understanding of whole-plant fitness and environmental adaptation. In this gap lie whole-plant organizational traits, including those that describe how plant biomass is allocated among organs and the timing of plant reproduction. This study explores the role of whole-plant organizational traits in adaptation to diverse environments in the context of life history, growth form and leaf economic strategy in a well-studied herbaceous system. Methods: A phylogenetic comparative approach was used in conjunction with common garden phenotyping to assess the evolution of biomass allocation and reproductive timing across 83 populations of 27 species of the diverse genus Helianthus (the sunflowers). Key Results: Broad diversity exists among species in both rel...研究背景与目的：基于功能性状的植物生态学（Trait-based plant ecology）旨在通过少量功能性状预测植物生态策略。然而，当前在器官级生理生态性状的认知与整株植物适合度及环境适应性的认知之间，存在显著认知鸿沟。填补这一鸿沟的正是整株植物组织性状，涵盖描述植物生物量在各器官间分配模式以及植物繁殖时序的相关性状。本研究以经广泛研究的草本类群为研究系统，在生活史、生长型与叶片经济策略的框架下，探讨整株植物组织性状在适应多样环境中的作用。 研究方法：本研究采用系统发育比较分析方法结合同质园表型分析，对27个物种共83个种群的向日葵属（Helianthus）类群的生物量分配与繁殖时序演化进行评估。 主要结果：各物种在生物量分配及繁殖时序两个维度均存在广泛的多样性。