Wu Yun, Liu Guangli, Sletvold Nina, Duan Xuyu, Tong Zhaoli, Li Qingjun
School of Architecture and Civil Engineering, Xihua University, Chengdu, 610039, China.
College of Landscape Architecture, Sichuan Agricultural University, Chengdu, 611130, China.
New Phytol. 2023 Jan;237(2):672-683. doi: 10.1111/nph.18537. Epub 2022 Nov 17.
The individual and combined effects of abiotic factors on pollinator-mediated selection on floral traits are not well documented. To examine potential interactive effects of water and nutrient availability on pollinator-mediated selection on three floral display traits of Primula tibetica, we manipulated pollination and nutrient availability in a factorial experiment, conducted at two common garden sites with different soil water content (natural vs addition). We found that both water and nutrient availability affected floral trait expression in P. tibetica and that hand pollination increased seed production most when both nutrient content and water content were high, indicating joint pollen and resource limitation. We documented selection on all floral traits, and pollinators contributed to directional and correlational selection on plant height and number of flowers. Soil water and nutrient availability interactively influenced the strength of both pollinator-mediated directional and correlational selection, with significant selection observed when nutrient or water availability was high, but not when none or both were added. The results suggest that resource limitation constrains the response of P. tibetica to among-individual variation in pollen receipt, that addition of nutrients or water leads to pollinator-mediated selection and that effects of the two abiotic factors are nonadditive.
非生物因素对传粉者介导的花部性状选择的个体效应和综合效应尚无充分记录。为了研究水分和养分有效性对传粉者介导的藏报春三种花部展示性状选择的潜在交互作用，我们在两个具有不同土壤含水量（自然状态与添加水分）的共同园址进行了析因实验，对授粉和养分有效性进行了操控。我们发现，水分和养分有效性均影响藏报春的花部性状表达，并且当养分含量和水分含量都很高时，人工授粉使种子产量增加最多，这表明存在花粉和资源的共同限制。我们记录了对所有花部性状的选择，传粉者对植株高度和花的数量进行了定向选择和相关选择。土壤水分和养分有效性交互影响传粉者介导的定向选择和相关选择的强度，当养分或水分有效性较高时观察到显著选择，但在不添加或同时添加两者时则未观察到显著选择。结果表明，资源限制制约了藏报春对个体间花粉接受差异的响应，添加养分或水分会导致传粉者介导的选择，并且这两种非生物因素的效应是非累加的。
