High lifetime inbreeding depression counteracts the reproductive assurance benefit of selfing in a mass-flowering shrub.
High lifetime inbreeding depression counteracts the reproductive assurance benefit of selfing in a mass-flowering shrub.
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DOI：
10.1186/s12862-014-0243-7
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发表时间：
2014-11-30
影响因子：
3.4
通讯作者：
Pornon A
中科院分区：
文献类型：
--
作者：
Delmas CE;Cheptou PO;Escaravage N;Pornon A
交配和/或传粉者可获得性的下降预计会影响植物交配系统的选择压力。自花受精的增加可能是为了补偿授粉失败的负面影响。然而，在不同的授粉环境中自交的效益取决于自交和异交后代的相对适合度。我们研究了自交在多年生植物长寿物种的一生中提供生殖保证的可能性及其在不同大小的植物斑块之间的变化。斑块的大小可能会影响交配和传粉者的可获得性，从而影响授粉成功率和自交率。我们估计了杜鹃(杜鹃科)天然斑块的结实和结实、繁殖保证、自交亲和性、多位点斑块自交率和终生近交衰退。开放结实率随着斑块大小的增加呈线性下降，而传粉者介导的结实率(去雄花)则没有受到显著影响。子代阵列分析表明，自交率随着斑块大小的增加而下降，这与小稀疏斑块比大密度斑块具有更大的生殖保证是一致的。然而，坐果率和成虫适合度随着斑块大小的减小而降低，估计平均寿命近亲交配抑制为0.9(通过比较成虫和后代的F值获得)。终生近亲繁殖衰退强烈地抵消了这种长寿物种由于自交而获得生殖保障的优势。自交后代的不良适合性应该会抵消任何向自交的进化，尽管它有可能减轻花粉限制的负面后果。这项研究强调，如果我们要了解自交的实际好处，避免高估生殖保证，就需要估计终身近交衰退，以及交配系统和授粉参数。本文的在线版本(doi：10.1186/s12862-0140243-7)包含补充材料，授权用户可以使用。
Decreases in mate and/or pollinator availability would be expected to affect the selective pressure on plant mating systems. An increase in self-fertilization may evolve to compensate for the negative effects of pollination failure. However, the benefit of selfing in variable pollination environments depends on the relative fitnesses of selfed and outcrossed progeny. We investigated the potential for selfing to provide reproductive assurance over the lifetime of a long-lived perennial species and its variation between plant patches of various sizes. Patch size is likely to affect mate and pollinator availabilities, thereby affecting pollination success and the rate of selfing. We estimated fruit and seed set, reproductive assurance, self-compatibility, the multilocus patch selfing rate and lifetime inbreeding depression in natural patches of Rhododendron ferrugineum (Ericaceae), a mass-flowering species characterized by considerable patch size variation (as estimated by the total number of inflorescences). Open seed set declined linearly with increasing patch size, whereas pollinator-mediated seed set (emasculated flowers) was not significantly affected. Progeny array analysis indicated that the selfing rate declined with increasing patch size, consistent with greater reproductive assurance in small sparse patches than in large, dense patches. However, fruit set and adult fitness decreased with decreasing patch size, with an estimated mean lifetime inbreeding depression of 0.9 (obtained by comparing F values in adults and progenies). Lifetime inbreeding depression strongly counteracts the advantage of reproductive assurance due to selfing in this long-lived species. The poor fitness of selfed offspring should counteract any evolution towards selfing, despite its potential to alleviate the negative consequences of pollen limitation. This study highlights the need to estimate lifetime inbreeding depression, together with mating system and pollination parameters, if we are to understand the actual benefit of selfing and avoid the overestimation of reproductive assurance. The online version of this article (doi:10.1186/s12862-014-0243-7) contains supplementary material, which is available to authorized users.
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影响因子：
4.8
作者：
Jones, CG;Lawton, JH;Shachak, M
通讯作者：
Shachak, M
影响因子：
3.3
作者：
CHARLESWORTH, D;CHARLESWORTH, B
通讯作者：
CHARLESWORTH, B
影响因子：
2.9
作者：
Cheptou, Pierre-Olivier;Massol, Francois
通讯作者：
Massol, Francois
影响因子：
3
作者：
Delmas, Chloe E. L.;Lhuillier, Emeline;Escaravage, Nathalie
通讯作者：
Escaravage, Nathalie
影响因子：
2.1
作者：
Cheptou, PO;Imbert, E;Escarre, J
通讯作者：
Escarre, J