I. VARIATION WITHIN AND AMONG POPULATIONS
I. VARIATION WITHIN AND AMONG POPULATIONS
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I. 人群内部和人群之间的差异
DOI：
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发表时间：
1989
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通讯作者：
D. L. Venable
中科院分区：
文献类型：
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作者：
D. L. Venable
我们记录了种子异形物种 Heterosperma pinnatum Cav 群体内部和群体之间的表型和遗传变异。 （菊科）在种子形态的生产以及可能与种子和头部性状相关的各种生活史和形态特征中。发现每个性状在大多数或通常所有人群中都具有显着的遗传变异。除每头瘦果数和幼苗形状外，所有性状均存在显着的群体间遗传变异，尽管某些性状在群体间的遗传变异远小于群体内的遗传变异。与群体内的变异相比，每头中间瘦果的数量和百分比、每头瘦果的总数以及中央和外围瘦果的长度几乎没有群体间遗传变异。大多数性状在群体之间的遗传变异略小于群体内部的遗传变异。然而，一些性状（中央瘦果的百分比、芒的长度、第一个花序开放的日期、第一个果序开放的日期和死亡日期）具有更多的群体间遗传变异。除中间瘦果外，所产生的瘦果变体的比例具有较高的广义遗传力和较高的群体间遗传变异。所有物候变量都具有较高的群体间遗传变异。初花期和结果期的群体内遗传力较高，而死亡期和繁殖间隔期的群体内遗传力较低。在温室中测量的具有高广义遗传力或群体间遗传方差的性状的家庭和群体平均值与相应家庭或群体的现场平均值密切相关。在田间和温室中测量的性状的表型变异量相似。这些证据表明温室结果为该物种在田间的遗传变异提供了合理的估计。许多研究报告了不同异形种子物种的种子形态比例的变化，并讨论了种子比例进化的适应性情景。然而，我们的研究是少数几个记录了种群内部和种群间表型和遗传变异数量的研究之一。
We document phenotypic and genetic variation within and among populations of the seed heteromorphic species Heterosperma pinnatum Cav. (Compositae) in the production of seed morphs and in a variety of life-history and morphological characteristics that might be correlated with seed and head traits. Each trait is found to have significant genetic variance in most or, usually, all populations. Significant among-population genetic variation exists for all traits except number of achenes per head and seedling shape, although some traits have much less genetic variation among than within populations. Number and percentage of intermediate achenes per head, total number of achenes per head, and lengths of central and peripheral achenes had little among- population genetic variation compared to within-population variation. Most traits had slightly less genetic variation among than within populations; however, some traits (percentage of central achenes, length of awns, date that the first flowering head opened, date that the first fruiting head opened, and death date) had more among-population genetic variation. The proportions of achene morphs produced had high broad-sense heritabilities and high among-population genetic variance, except in the case of intermediate achenes. All phenological variables had high among-population genetic variation. Within-population heritabilities were high for dates of first flowering head and fruiting head but low for death date and reproductive interval. Family and population means measured in the greenhouse for traits having high broad-sense heritability or among-population genetic variance were closely correlated with field means for the corresponding families or populations. The amounts of phenotypic variation were similar for traits that were measured in both the field and the greenhouse. These lines of evidence suggest that greenhouse results provide reasonable estimates of genetic variation in the field for this species. Numerous studies have reported variation in the proportion of seed morphs for different het- eromorphic-seeded species and have discussed adaptive scenarios for the evolution of seed pro- portions; however, our investigation is one of only a few that have documented the amount of phenotypic and genetic variation within and among populations.