Kelly Carol A
Department of Plant Biology, Morrill Hall, 505 S. Goodwin Ave., Urbana, IL, 61801, USA.
Evolution. 1993 Feb;47(1):88-97. doi: 10.1111/j.1558-5646.1993.tb01201.x.
Despite numerous adaptive scenarios concerning the evolution of plant life-history phenologies few studies have examined the heritable basis for and genetic correlations among these phenologies. Documentation of genetic variation for and covariation among reproductive phenologies is important because it is this variation/covariation that will determine the potential for response to evolutionary forces. To address this problem, I conducted a breeding experiment to determine narrow-sense heritabilities for and genetic correlations among the phenologies of life-history events and plant size in Chamaecristafasciculata, a temperate summer annual plant species. Paternal families showed no evidence of heritable variation for two estimates of plant size, six measures of reproductive phenology or two fitness components. Similarly, paternal estimates of genetic correlations among these traits were low or zero. In contrast, maternal estimates of heritability suggested the influence of maternal parent on one estimate of plant size and four phenological traits. Likewise, maternal effects influenced maternal estimates of genetic correlations. These maternal effects can arise from three sources: endosperm nuclear, cytoplasmic genetic and/or maternal phenotypic. The degree to which the phenology of one life-history trait acts as a constraint on the evolution of other phenological traits depends on the source of the maternal influence in this species.
尽管关于植物生活史物候演变存在众多适应性情景，但很少有研究考察这些物候的遗传基础及其之间的遗传相关性。记录生殖物候的遗传变异及其协变很重要，因为正是这种变异/协变将决定对进化力量作出反应的潜力。为解决这个问题，我进行了一项育种实验，以确定一种温带夏季一年生植物—— fasciculata 的生活史事件物候和植株大小的狭义遗传力及其之间的遗传相关性。父本家系在两种植株大小估计值、六种生殖物候测量值或两种适合度成分方面未显示出遗传变异的证据。同样，这些性状之间父本的遗传相关性估计值很低或为零。相比之下，母本的遗传力估计表明母本对一种植株大小估计值和四个物候性状有影响。同样，母体效应影响了母本对遗传相关性的估计。这些母体效应可源于三个方面：胚乳核、细胞质遗传和/或母体表型。一个生活史性状的物候对其他物候性状进化的限制程度取决于该物种中母体影响的来源。
