Multi-year stigmatic pollen-load sampling reveals temporal stability in interspecific pollination of flowers in a subalpine meadow
Multi-year stigmatic pollen-load sampling reveals temporal stability in interspecific pollination of flowers in a subalpine meadow
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多年柱头花粉负载采样揭示了亚高山草甸花卉种间授粉的时间稳定性
DOI：
10.1111/oik.06447
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发表时间：
2019-12-01
期刊：
影响因子：
3.4
通讯作者：
Huang, Shuang-Quan
中科院分区：
文献类型：
--
作者：
Fang, Qiang;Gao, Jie;Huang, Shuang-Quan
共花植物通常会经历种间授粉。然而，种间授粉是否是一个很大程度上随机的过程，或者多年来是否足够一致，以选择可以减少种间授粉或改善其对繁殖的有害影响的性状，这仍然是未知的。为了评估这一前提条件被满足的可能性，柱头花粉负荷17-34昆虫授粉植物在中国西南部亚高山草甸连续三年进行了评分。不同植物柱头上异种花粉的数量和比例存在显著差异。HP物种的数量和花粉负荷的比例是HP为每个受体物种之间呈正相关（反映在成对的相关性为所有逐年组合）。虽然年际变化是较小的同种花粉（CP）比HP负载，物种往往经历一贯高或一贯低HP比例跨年。我们发现，具有较高的柱头HP比例的物种一般经历了较低的柱头HP的比例变化，一个意想不到的结果，如果高HP负载是罕见的随机事件的结果。异种花粉的柱头负荷年间一致性的新发现表明，适应HP的柱头负荷是可能的，两个不同的策略可能已经演变：HP回避和HP耐受。时间一致的HP水平的物种之间的差异的观察支持的想法，自然选择可能是操作，以增加耐受性或减少异源花粉的到达柱头共花植物。这样的适应可能是重要的维持高水平的本地植物多样性的生物多样性热点，如我们的研究领域。
Co-flowering plants may commonly experience interspecific pollination. It remains unknown, however, whether interspecific pollination is a largely stochastic process or consistent enough over years to exert selection for traits that can reduce interspecific pollination or ameliorate its deleterious effects on reproduction. To assess the likelihood of this precondition being met, stigmatic pollen loads on 17-34 insect-pollinated plant species over three consecutive years were scored in a subalpine meadow in southwestern China. Plant species varied significantly in the amount and proportion of heterospecific pollen (HP) on stigmas. Both the number of HP species and the proportion of the pollen load that was HP for each recipient species correlated positively between years (reflected in pairwise correlations for all year-by-year combinations). Although inter-annual variation was smaller for conspecific pollen (CP) than for HP loads, species tended to experience either consistently high or consistently low HP proportions across years. We found that species with higher stigmatic HP proportions generally experienced lower proportional variation in stigmatic HP, an unexpected result if high HP loads are the result of rare stochastic events. The novel finding of between-year consistency in stigmatic loads of heterospecific pollen suggests that adaption to stigmatic loads of HP is possible, and two divergent strategies may have evolved: HP avoidance and HP tolerance. The observation of temporally consistent differences among species in levels of HP supports the idea that natural selection may be operating either to increase tolerance or to minimize arrival of heterospecific pollen on stigmas in co-flowering plants. Such adaptations may be important for the maintenance of high levels of local plant diversity in biodiversity hotspots such as our study area.