Among-individual variation in pollen limitation and inbreeding depression in a mixed-mating shrub
Among-individual variation in pollen limitation and inbreeding depression in a mixed-mating shrub
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DOI：
10.1093/aob/mcq200
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发表时间：
2010-12-01
期刊：
影响因子：
4.2
通讯作者：
Traveset, Anna
中科院分区：
文献类型：
--
作者：
Gonzalez-Varo, Juan P.;Traveset, Anna
植物个体间的近交衰退（delta）变异被认为在交配系统进化和群体遗传学中起着重要作用。此外，这种变异可能与个体对花粉限制（PL）的易感性有关，因为那些受种子产生德尔塔强烈影响的个体将需要更多的异交花粉来结出给定数量的果实或种子。然而，没有研究明确测试PL和三角洲之间的关联在单个工厂的水平。本研究评估了混合交配灌木桃金娘PL和delta的个体差异程度，delta在不同生活阶段的一致性，以及个体PL和delta之间的关系。公社人口。与自交相比，异花授粉提高了单果种子数、发芽率和幼苗生长量，但没有提高坐果率。只有种子数每果花粉有限，因此，累积花粉限制更多地取决于花粉质量（异交花粉）比数量。Delta的影响在不同的生命阶段和不同的植物之间有很大的差异。个体间的累积增量较高（平均增量= 0，中心点65），尽管在不同生命阶段的增量值之间没有正相关。有趣的是，母体植物表现出较强的三角洲种子生产更多的花粉有限，但他们也较少受影响的三角洲幼苗生长，因为种子大小/数量tradeoff.Results显示出一般的不一致性，在三角洲的生命阶段和个人，这表明不同的有害基因座在不同的阶段发挥作用。三角洲和PL在个人水平之间的关联证实了花粉限制可能是“基因型依赖”的想法，无论其他因素。
Variation in inbreeding depression (delta) among individual plants is considered to play a central role in mating system evolution and population genetics. Moreover, such variation could be linked to individual susceptibility to pollen limitation (PL) because those individuals strongly affected by delta for seed production will require more outcross pollen for setting a given number of fruits or seeds. However, no study has tested explicitly for associations between PL and delta at the individual plant level. This study assesses the extent of among-individual variation in PL and delta, the consistency of delta across life stages, and the relationships between individual PL and delta in the mixed-mating shrub Myrtus communis.Controlled hand-pollinations were performed in a natural M. communis population. Marked flowers were monitored until fruit production and a greenhouse experiment was conducted with the seeds produced.Compared with selfing, outcross-pollination enhanced seed number per fruit, germination rate and seedling growth, but did not enhance fruit-set. Only seed number per fruit was pollen limited and, thus, cumulative pollen limitation depended more on pollen quality (outcross pollen) than on quantity. The effects of delta varied considerably across life stages and individual plants. Cumulative delta was high across individuals (mean delta = 0 center dot 65), although there were no positive correlations between delta values at different life stages. Interestingly, maternal plants showing stronger delta for seed production were more pollen limited, but they were also less affected by delta for seedling growth because of a seed size/number trade-off.Results show a general inconsistency in delta across life stages and individuals, suggesting that different deleterious loci are acting at different stages. The association between delta and PL at the individual level corroborates the idea that pollen limitation may be 'genotype-dependent' regardless of other factors.