Chen Min, Wang Zheng-Jiao-Yi, Ma Xu-Jun, Zhao Xue-Yong
State Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China.
Urat Desert-grassland Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China.
Front Plant Sci. 2025 Jun 5;16:1522871. doi: 10.3389/fpls.2025.1522871. eCollection 2025.
Flowering shrubs in fragmented habitats often experience pollen limitation, which can lead to strong natural selection on floral display and affect reproductive success. Effective management and protection of dominant shrubs in fragmented habitats require a thorough understanding of the factors driving plant reproduction. However, the impact of fragmented habitats on reproductive success through floral display and pollinator visitation has not been experimentally quantified. We examined pollen limitation by comparing female fitness between open-pollinated and hand-pollinated plants. We also assessed the impact of natural selection (β) on floral display by comparing natural selection gradients in plants from natural and fragmented habitats. Our results show that this species is pollen-limited, with supplemental pollen increasing female fitness by 32%. This species exhibits directional selection for more open flowers and longer keel petals. We found that the number of open flowers is the main factor influencing pollinator visitation frequency and female fitness, and that pollinator visitation positively affects female fitness. This study provides insights into how fragmented habitats influence linear selection gradients related to the number of open flowers. Furthermore, this study highlights that fragmented habitats significantly influence reproductive success, with floral display being a crucial factor to consider when designing conservation strategies for this population.
碎片化栖息地中的开花灌木常常面临花粉限制，这可能导致对花展示的强烈自然选择，并影响繁殖成功率。有效管理和保护碎片化栖息地中的优势灌木需要全面了解驱动植物繁殖的因素。然而，碎片化栖息地通过花展示和传粉者访花对繁殖成功率的影响尚未通过实验进行量化。我们通过比较自由授粉和人工授粉植物的雌性适合度来研究花粉限制。我们还通过比较来自自然栖息地和碎片化栖息地的植物的自然选择梯度，评估了自然选择（β）对花展示的影响。我们的结果表明，该物种受到花粉限制，补充花粉可使雌性适合度提高32%。该物种对更开放的花朵和更长的龙骨瓣表现出定向选择。我们发现开放花朵的数量是影响传粉者访花频率和雌性适合度的主要因素，并且传粉者访花对雌性适合度有积极影响。这项研究揭示了碎片化栖息地如何影响与开放花朵数量相关的线性选择梯度。此外，这项研究强调碎片化栖息地显著影响繁殖成功率，在为该种群设计保护策略时，花展示是一个需要考虑的关键因素。
