Clines in traits compared over two decades in a plant hybrid zone
Clines in traits compared over two decades in a plant hybrid zone
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DOI：
10.1093/aob/mcy072
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发表时间：
2018-08-01
期刊：
影响因子：
4.2
通讯作者：
Trujillo, Gabriel
中科院分区：
文献类型：
--
作者：
Campbell, Diane R.;Faidiga, Alexandra;Trujillo, Gabriel
背景和目的杂交区性状的渐变反映了自然选择和基因流动之间的平衡。性状的平均值随时间的变化，特别是其渐变系的形状，很少在植物中研究，但可能是由于在一个不稳定的杂交区的进化。方法沿着海拔梯度对12个居群的5个花部性状和2个营养部性状进行了测定。我们比较了25年前测量的花的特征。观察到的平均性状值的变化进行了比较与预测的基础上事先估计的自然选择。我们还比较了陡峭度和位置之间的花和vegetative characteristic.Key结果花冠长度增加了五代以上的程度相匹配的预测从测量表型选择和遗传力。它的食物形状和其他特征没有明显的变化。不同性状的倾斜，但不是所有的花性状表现出陡峭的倾斜比营养性状。这两套房的形态特征有陡峭的倾斜比中性molecular markers.Conclusions花冠长度的增加提供了一个罕见的例子，预测和观察到的进化之间的匹配的植物性状在自然种群。的渐变特性是一致的假设，即生境介导的分歧选择的营养性状和传粉媒介介导的选择花性状都保持物种的差异，在整个混合区。
Background and Aims Clines in traits across hybrid zones reflect a balance between natural selection and gene flow. Changes over time in average values for traits, and especially the shapes of their clines, arc rarely investigated in plants, but could result from evolution in an unstable hybrid zone. Differences in dines between floral and vegetative traits could indicate different strengths of divergent selection.Methods Five floral and two vegetative traits were measured in 12 populations along an elevational gradient spanning a natural hybrid zone between Ipomopsis aggregaia and Ipomopsis tenuituba. We compared dines in the floral traits with those measured 25 years ago. Observed changes in mean trait values were compared with predictions based on prior estimates of natural selection. We also compared the steepness and position of dines between the floral and vegetative traits.Key Results Corolla length has increased over five generations to an extent that matches predictions from measurements of phenotypic selection and heritability. The shape of its dine, and that of other traits, has not changed detectably. Clines varied across traits, but not all floral traits showed steeper clines than did vegetative traits. Both suites of morphological traits had steeper clines than did neutral molecular markers.Conclusions The increase in corolla length provides a rare example of a match between predicted and observed evolution of a plant trait in natural populations. The clinal properties are consistent with the hypothesis that habitat-mediated divergent selection on vegetative traits and pollinator-mediated selection on floral traits both maintain species differences across the hybrid zone.