Genetic basis of reproductive isolation in Solanum Sect. Lycopersicon

由于繁殖障碍，物种彼此隔离，因此它们的杂交后代通常是不能存活和/或不育的。这项研究计划包括三个项目，研究包括驯化番茄在内的植物群中物种生殖隔离障碍的遗传基础。首先，将在两个物种之间的杂交群体中使用“性状作图”来确定导致物种屏障的基因的染色体位置。其次，不同物种共享相同生殖隔离基因的程度将通过杂交基因型之间的经典遗传杂交来检验。第三，利用分子遗传标记的重组“精细定位”，将发现位于已识别染色体区域内的特定基因。确定导致杂交不育的基因可以提供对基本生物过程的洞察，包括新物种是如何形成的，以及哪些基因有助于生殖功能。此外，本研究具有实际应用价值。具有重要农艺意义的物种，如番茄的野生近缘种，是自然遗传变异（例如抗病或抗旱）的有用来源。了解这些物种之间生殖隔离的遗传机制有助于在作物改良过程中制定克服这些不育障碍的育种策略。

Species are isolated from each other by barriers to reproduction, so that their hybrids are generally inviable and/or sterile. The research proposal involves three projects that examine the genetic basis of species reproductive isolating barriers in the plant group that includes the domesticated tomato, Solanum lycopersicum. First, the chromosomal location of genes that contribute to species barriers will be identified using "trait mapping" in hybrid populations between two species. Second, the degree to which different species share the same reproductive isolating genes will be examined using classical genetic crosses between hybrid genotypes. Third, the specific genes that lie within identified chromosomal regions will be uncovered, using recombinational "fine-mapping" with molecular genetic markers. Identifying the genes that cause hybrid sterility can provide insight into fundamental biological processes, including how new species are formed, and which genes contribute to reproductive functions. In addition, this research has practical applications. Wild relatives of agronomically-important species, such as tomato, are useful sources of natural genetic variation (e.g. for disease resistance, or tolerance to drought stress). Understanding the genetic mechanisms of reproductive isolation between these species can aid in developing breeding strategies to overcome these sterility barriers during crop improvement.