首页分享克拉克亚麻（柳叶菜科）叶片的发育稳定性与种群异交率和杂合性的关系

克拉克亚麻（柳叶菜科）叶片的发育稳定性与种群异交率和杂合性的关系

来源：花匠小妙招时间：2026-02-12 21:39

Abstract

Four natural populations of Clarkia tembloriensis, whose levels of heterozygosity and rates of outcrossing were previously found to be correlated, are examined for developmental instability in their leaves. From the northern end of the species range, we compare a predominantly selfing population (t̂ = 0.26) with a more outcrossed population (t̂ = 0.84), which is genetically similar. From the southern end of the range, we compare a highly selfing population (t̂ = 0.03) with a more outcrossed population (t̂ = 0.58). We measured developmental stability in the populations using two measures of within-plant variation in leaf length as well as calculations of fluctuating asymmetry (FA) for several leaf traits. Growth-chamber experiments show that selfing populations are significantly more variable in leaf length than more outcrossed populations. Developmental instability can contribute to this difference in population-level variance. Plants from more homozygous populations tend to have greater within-plant variance over developmentally comparable nodes than plants from more heterozygous populations, but the difference is not significant. At the upper nodes of the plant, mature leaf length declines steadily with plant age, allowing for a regression of leaf length on node. On average, the plants from more homozygous populations showed higher variance about the regression (MSE) and lower R values, suggesting that the decline in leaf length with plant age is less stable in plants from selfing populations than in plants from outcrossing populations. Fluctuating asymmetry (FA) was calculated for four traits within single leaves at up to five nodes per plant. At the early nodes of the plant where leaf arrangement is opposite, FA was also calculated for the same traits between opposite leaves at a node. Fluctuating asymmetry is significantly greater in the southern selfing population than in the neighboring outcrossed population. Northern populations do not differ in FA. Fluctuating asymmetry can vary significantly between nodes. The FA values of different leaf traits were not correlated. We show that developmental stability can be measured in plants using FA and within-plant variance. Our data suggest that large differences in breeding system are associated with differences in stability, with more inbred populations being the least stable.

摘要

先前已发现其杂合度水平和异交率存在相关性的特姆布勒氏克拉花（Clarkia tembloriensis）的四个自然种群，被检测了叶片的发育稳定性。从该物种分布范围的北端，我们将一个主要自交的种群（t̂ = 0.26）与一个遗传上相似但异交程度更高的种群（t̂ = 0.84）进行比较。从分布范围的南端，我们将一个高度自交的种群（t̂ = 0.03）与一个异交程度更高的种群（t̂ = 0.58）进行比较。我们使用叶片长度的两种植株内变异测量方法以及对几个叶片性状的波动不对称性（FA）计算来测量种群中的发育稳定性。生长室实验表明，自交种群的叶片长度变异显著大于异交程度更高的种群。发育不稳定性可能导致种群水平方差的这种差异。与来自杂合度更高的种群的植株相比，来自纯合度更高的种群的植株在发育相当的节上往往具有更大的植株内方差，但差异不显著。在植株的上部节位，成熟叶片长度随植株年龄稳步下降，从而可以对叶片长度与节位进行回归分析。平均而言，来自纯合度更高的种群的植株在回归分析中显示出更高的方差（均方误差）和更低的R值，这表明自交种群的植株中叶片长度随植株年龄的下降比异交种群的植株更不稳定。对单叶内多达五个节位的四个性状计算波动不对称性（FA）。在植株早期节位，叶片排列为对生时，还对一个节上对生叶片之间的相同性状计算波动不对称性。南部自交种群的波动不对称性显著大于相邻的异交种群。北部种群在波动不对称性方面没有差异。波动不对称性在不同节位之间可能有显著差异。不同叶片性状的FA值不相关。我们表明，可以使用波动不对称性和植株内方差来测量植物的发育稳定性。我们的数据表明，繁殖系统的巨大差异与稳定性差异相关，自交程度更高的种群最不稳定。