The relationship between flower size, inbreeding coefficient and inferred selfing rate in British Euphrasia species
The relationship between flower size, inbreeding coefficient and inferred selfing rate in British Euphrasia species
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DOI：
10.1038/sj.hdy.6800553
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发表时间：
2005-01-01
期刊：
影响因子：
3.8
通讯作者：
Hollingsworth, PM
中科院分区：
文献类型：
--
作者：
French, GC;Ennos, RA;Hollingsworth, PM
Euphrasia属在英国包括一个分类学上复杂的组自交亲和，形态相似，半寄生，一年生植物物种的高度保护的重要性。目前已知的19个二倍体和四倍体类群在花的大小上表现出显著的差异。本文的目的是确定是否存在的关系，花的大小和饲养系统内Euphrasia。在对19个类群的花大小变异进行调查后，选择了7个二倍体种群进行详细研究。利用4个核微卫星位点估计了群体内的近交系数F_1。F-is值在0.17-0.77之间变化，与花的大小呈显著负相关。这些结果是最好的解释，在自交率之间的变化的结果幼穗大戟种群，随着花的大小减少，自交率增加。讨论了影响Euphrasia育种系统进化的潜在因素，以及自花受精在产生分类复杂性和促进属内谱系分化中的作用。
The genus Euphrasia in Britain comprises a taxonomically complex group of self-compatible, morphologically similar, hemi-parasitic, annual plant species of high conservation importance. The 19 diploid and tetraploid taxa currently recognised show striking variation in flower size. The objective of this paper is to determine whether a relationship exists between flower size and breeding system within Euphrasia. Following a survey of flower size variation among the 19 taxa, seven diploid populations, encompassing a broad range of flower sizes, were selected for detailed study. Four nuclear microsatellite loci were used to estimate the inbreeding coefficient F-is within each population. F-is values varied from to 0.17-0.77 and showed a significant, negative correlation with flower size. These results are best explained as the consequence of variation in selfing rate among the Euphrasia populations, with selfing rate increasing as flower size decreases. The potential factors influencing breeding system evolution in Euphrasia are discussed, together with the role of autogamy in generating taxonomic complexity and facilitating lineage differentiation within the genus.