INBREEDING DEPRESSION IN PARTIALLY SELF-FERTILIZING DECODON VERTICILLATUS (LYTHRACEAE) - POPULATION-GENETIC AND EXPERIMENTAL ANALYSES
INBREEDING DEPRESSION IN PARTIALLY SELF-FERTILIZING DECODON VERTICILLATUS (LYTHRACEAE) - POPULATION-GENETIC AND EXPERIMENTAL ANALYSES
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DOI：
10.1111/j.1558-5646.1994.tb05285.x
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发表时间：
1994-08-01
期刊：
影响因子：
3.3
通讯作者：
BARRETT, SCH
中科院分区：
文献类型：
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作者：
ECKERT, CG;BARRETT, SCH
近交衰退是有花植物异交的主要选择力。然而，一些自花受精，应该通过暴露遗传负荷来削弱近亲繁殖的有害影响。本研究探讨了长寿的草本湿地植物Decodon verticillatus（L.）埃尔（千屈菜科）。根据对10个种群的估计，30%的后代是通过自花受精产生的。根据相同10个种群的近交系数变化，对近交衰退的种群遗传估计（δ = 1 -自交后代的相对平均适合度）一致较高，范围为0.49至1.79，平均为1.11 +/- 0.29 SE。虽然个别人口估计值的置信区间很大，估计值显着大于0的6个人口和大于0.5的4个。近交衰退也估计通过比较生长，生存，开花的实验自交和异交的后代从这些人口中的两个在一年的温室实验，涉及三个密度制度，之后的后代被移植到花园阵列和两个领域的网站和监测连续两个生长季节。总的来说（$）超过帽三角洲的生存平均0.27 +/- 0.01在温室，0.33 +/- 0.04在花园，0.46 +/- 0.04在外地。温室实验还揭示了强烈的近交衰退的生长变量，特别是地上干重（（$）超过帽三角洲= 0.42 +/- 0.03）。如果生存到成熟是由严重的截断选择决定的，这些生长变量的近亲繁殖衰退的健身后果大约翻了一番。尽管大量自交，近交衰退似乎是一个主要的选择力，有利于维持异交在D。轮生的
Inbreeding depression is a major selective force favoring outcrossing in flowering plants. Some self-fertilization, however, should weaken the harmful effects of inbreeding by exposing genetic load to selection. This study examines the maintenance of inbreeding depression in partially self-fertilizing populations of the long-lived, herbaceous wetland plant, Decodon verticillatus (L.) Ell. (Lythraceae). Estimates from ten populations indicate that 30% of offspring are produced through self-fertilization. Population-genetic estimates of inbreeding depression (delta = 1 - relative mean fitness of selfed progeny) based on changes in the inbreeding coefficient for the same ten populations were uniformly high, ranging from 0.49 to 1.79 and averaging 1.11 +/- 0.29 SE. Although confidence intervals of individual population estimates were large, estimates were significantly greater than 0 in six populations and greater than 0.5 in four. Inbreeding depression was also estimated by comparing growth, survival, and flowering of experimentally selfed and outcrossed offspring from two of these populations in a l-yr glasshouse experiment involving three density regimes; after which offspring were transplanted into garden arrays and two field sites and monitored for two consecutive growing seasons. Overall ($) over cap delta for survival averaged 0.27 +/- 0.01 in the glasshouse, 0.33 +/- 0.04 in the garden, and 0.46 +/- 0.04 in the field. The glasshouse experiment also revealed strong inbreeding depression for growth variables, especially above-soil dry weight (($) over cap delta = 0.42 +/- 0.03). The fitness consequences of inbreeding depression for these growth variables approximately doubles if survival to maturity is determined by severe truncation selection. Despite substantial selfing, inbreeding depression appears to be a major selective force favoring the maintenance of outcrossing in D. verticillatus.