Chen Xufang, Zhang Yazhou, Qian Lishen, Zhou Renyu, Sun Hang, Chen Jianguo
State Key Laboratory of Plant Diversity and Specialty Crops, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China.
Yunnan Key Laboratory of Plateau Wetland Conservation, Restoration and Ecological Services, Southwest Forestry University, Kunming, Yunnan, China.
Plant Divers. 2023 Jul 14;46(2):247-255. doi: 10.1016/j.pld.2023.07.002. eCollection 2024 Mar.
When benefiting other beneficiaries, cushion plants may reciprocally receive feedback effects. The feedback effects on different sex morphs, however, remains unclear. In this study, taking the gynodioecious as a model species, we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio, and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios. The total beneficiary cover ratio was similar between females and hermaphrodites. Females produced much less flowers but more fruits than hermaphrodites. These results suggested that females and hermaphrodites possess similar facilitation intensity, and female cushion . may allocate more resources saved from pollen production to seed production, while hermaphrodites possibly allocate more resources to pollen production hence reducing seed production. The surface areas covered by beneficiaries produced less flowers and fruits than areas without beneficiaries. In addition, strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites, but the correlation strength were similar for these two sex morphs. However, the correlation between beneficiary cover and fruit cover was only significantly negative for females, suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on hermaphrodites. All the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion , with females possibly suffering greater cost than hermaphrodites. Such differentiation in reproductive costs between sex morphs, in long-term perspective, may imply sex imbalance in population dynamics.
在惠及其他受益植物时，垫状植物可能会相应地受到反馈效应的影响。然而，这种反馈效应在不同性别形态上的表现仍不清楚。在本研究中，我们以雌全异株植物作为模式物种，旨在通过测量受益植物的覆盖比例来评估垫状植物对不同性别的促进强度，并通过测量花和果实的覆盖比例来评估垫状植物在繁殖功能方面的潜在成本。雌性和雌雄同体植物的总受益植物覆盖比例相似。与雌雄同体植物相比，雌性植物产生的花较少，但果实较多。这些结果表明，雌性和雌雄同体植物具有相似的促进强度，雌性垫状植物可能会将节省下来的用于花粉生产的资源更多地分配到种子生产上，而雌雄同体植物可能会将更多资源分配到花粉生产上，从而减少种子生产。有受益植物覆盖的区域产生的花和果实比没有受益植物覆盖的区域少。此外，在雌性和雌雄同体植物中均检测到受益植物覆盖与花覆盖之间存在强烈的负相关，但这两种性别形态的相关强度相似。然而，受益植物覆盖与果实覆盖之间的相关性仅在雌性植物中显著为负，这表明受益植物对雌性植物的果实繁殖有负面影响，而对雌雄同体植物则有中性影响。所有结果表明，促进其他受益植物会给垫状植物带来繁殖成本，雌性植物可能比雌雄同体植物承受更大的成本。从长远来看，这种性别形态之间繁殖成本的差异可能意味着种群动态中的性别失衡。
