Does pollen competition reduce the cost of inbreeding?
Does pollen competition reduce the cost of inbreeding?
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DOI：
10.3732/ajb.91.11.1939
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发表时间：
2004-11-01
影响因子：
3
通讯作者：
Rogers, DG
中科院分区：
文献类型：
--
作者：
Armbruster, WS;Rogers, DG
我们假设，在被子植物中促进花粉竞争的花的功能可能已经演变，在某些情况下，不良反应的选择产生的负面影响近亲繁殖，至少在植物与混合交配系统。通过花粉竞争筛选单倍体基因型可以清除在单倍体花粉中表达的隐性（或加性）有害等位基因，因此可以降低自花授粉、异花受精或双亲近交的适合度成本。我们测试了这一假设的一个预测，即自花花粉之间竞争更激烈产生的后代比竞争不那么激烈产生的后代具有更高的适应性。用来自同一植物上的其它花的花粉为Dalechampia scandens（大戟科）花授粉（geitono-gamous自花受精）。这些花经历更激烈的花粉竞争，由于低花粉分散（位置差异）的柱头产生较重的种子和幼苗生长较快的胚根比花经历不太激烈的花粉竞争（高花粉分散），我们的假设所预测的。
We hypothesize that floral features promoting pollen competition in angiosperms may have evolved, in some cases, ill response to selection generated by the negative effects of inbreeding, at least in plants with mixed-mating systems. Screening of haploid genotypes through pollen competition may purge recessive (or additive) deleterious alleles that are expressed in haploid pollen and hence may reduce the fitness cost of self-pollination, geitonogamy, or biparental inbreeding. We tested one prediction of this hypothesis, that offspring produced by more intense competition among self-pollen have higher fitness than offspring produced by less intense competition. Dalechampia scandens (Euphorbiaceae) flowers were pollinated with pollen from other flowers on the same plant (geitono-gamous self-fertilization). Those flowers experiencing more intense pollen competition as a result of low pollen dispersion (positional variance) on the stigma produced heavier seeds and seedlings with faster-growing radicles than flowers experiencing less intense pollen competition (high pollen dispersion), as predicted by our hypothesis.