Evidence for maintenance of sex by pathogens in plants
Evidence for maintenance of sex by pathogens in plants
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DOI：
10.1111/j.0014-3820.2004.tb00886.x
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发表时间：
2004-11-01
期刊：
影响因子：
3.3
通讯作者：
Koslow, JM
中科院分区：
文献类型：
--
作者：
Busch, JW;Neiman, M;Koslow, JM
尽管自花受精具有显著的遗传优势，但异交的优势仍然是一个悖论。理论表明，选择可以有利于异交，如果它能够产生比通过自花受精产生的后代更不易受病原体攻击的后代。因此，如果病原体压力有助于维持植物中的异交，则在攻击植物物种的病原体物种的数量和植物物种的异交率之间可能存在正相关。我们通过研究异交率和真菌病原体物种的数量之间的关联来测试这一假设，这些真菌病原体物种攻击一个大的、分类学上多样化的种子植物。我们发现，植物物种攻击更多的真菌病原体物种有较高的异交率比植物较少的敌人。在校正了自然和农业植物物种之间的研究偏差后，这种关系仍然存在。我们还通过在我们的数据集中充分代表的属和科内进行遗传独立对比（PIC）来解释植物谱系之间关系的嵌套层次结构。对病原菌与异交PIC之间相关性的荟萃分析表明，病原菌种类数与异交率呈正相关。这种模式是一致的假设，病原体介导的选择可能有助于维持种子植物物种的异交。
The predominance of outcrossing despite the substantial transmission advantage of self-fertilization remains a paradox. Theory suggests that selection can favor outcrossing if it enables the production of offspring that are less susceptible to pathogen attack than offspring produced via self-fertilization. Thus, if pathogen pressure is contributing to the maintenance of outcrossing in plants, there may be a positive correlation between the number of pathogen species attacking plant species and the outcrossing rate of the plant species. We tested this hypothesis by examining the association between outcrossing rate and the number of fungal pathogen species that attack a large, taxonomically diverse set of seed plants. We show that plant species attacked by more fungal pathogen species have higher outcrossing rates than plants with fewer enemies. This relationship persists after correcting for study bias among natural and agricultural species of plants. We also accounted for the nested hierarchy of relationships among plant lineages by conducting phylogenetically independent contrasts (PICs) within genera and families that were adequately represented in our dataset. A meta-analysis of the correlation between pathogen and outcrossing PICs shows that there is a positive correlation between pathogen species number and outcrossing rates. This pattern is consistent with the hypothesis that pathogen-mediated selection may contribute to the maintenance of outcrossing in species of seed plants.