Moyle Leonie C
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
J Hered. 2007 Mar-Apr;98(2):123-35. doi: 10.1093/jhered/esl062. Epub 2007 Jan 17.
I compare the genetic basis of quantitative traits that potentially contribute to pre- and postzygotic isolation between the plant species Solanum lycopersicum (formerly Lycopersicon esculentum) and Solanum habrochaites (formerly Lycopersicon hirsutum), using quantitative trait loci (QTL) mapping in a set of near-isogenic lines. Putative prezygotic isolating traits include flower size, flower shape, stigma exertion, and inflorescence length, that can influence pollinator preferences and/or selfing rates, and therefore gene flow between divergent types. Postzygotic isolating traits are hybrid pollen and seed sterility. Three substantive results emerge from these analyses. First, the genetic basis of floral differentiation appears to be somewhat less complex than the genetic basis of postzygotic hybrid sterility, although these differences are very modest. Second, there is little evidence that traits for floral differentiation are causally or mechanistically associated with hybrid sterility traits in this species cross. Third, there is little evidence that hybrid sterility QTL are more frequently associated with chromosomal centromeric regions, in comparison to floral trait QTL, a prediction of centromeric drive models of hybrid sterility. Although genome-wide associations are not evident in this analysis, several individual chromosomal regions that contain clusters of QTL for both floral and sterility traits, or that indicate hybrid sterility effects at centromere locations, warrant further fine-scale investigation.
我利用一组近等基因系中的数量性状基因座（QTL）定位，比较了可能导致番茄（Solanum lycopersicum，原名为Lycopersicon esculentum）和多毛番茄（Solanum habrochaites，原名为Lycopersicon hirsutum）这两种植物物种之间合子前和合子后隔离的数量性状的遗传基础。假定的合子前隔离性状包括花大小、花形状、柱头外露和花序长度，这些性状会影响传粉者偏好和/或自交率，进而影响不同类型之间的基因流动。合子后隔离性状是杂种花粉和种子不育。这些分析得出了三个重要结果。第一，花分化的遗传基础似乎比合子后杂种不育的遗传基础稍微简单一些，尽管这些差异非常小。第二，几乎没有证据表明在这个物种杂交中，花分化性状与杂种不育性状存在因果或机制上的关联。第三，与花性状QTL相比，几乎没有证据表明杂种不育QTL更频繁地与染色体着丝粒区域相关，这是杂种不育着丝粒驱动模型的一个预测。尽管在该分析中未发现全基因组关联，但几个同时包含花和不育性状QTL簇，或在着丝粒位置显示杂种不育效应的单个染色体区域，值得进一步进行精细尺度的研究。
