报春苣苔属同域分布近缘物种生殖隔离的遗传基础

Reproductive isolation plays an important role in maintaining species integrity. Studies of the genetic basis of reproductive isolation traits are vitally important for understanding the origin and evolution of the biodiversity, and instructive for endemic plants conservation. Primulina is one of the largest genera of the Old World Gesneriaceae, and most of them are endemic to karst landscapes. In this research proposal, we use RAD-seq based quantitative trait loci (QTL) analysis to investigate the genetic architecture of postzygotic reproductive isolation in two closely sympatric Primulina species (Primulina eburnea and P. mabaensis). We first construct a high-density linkage map with an F2 population, and then we conduct analysis for a suite of reproductive isolation barriers including hybrid male fertility and hybrid seeds viability. In addition, we detect genomic islands and relationships between islands and QTLs underlying reproductive isolation. The goal of this study is to determine the number, location and effect of the QTLs and identify genomic mechanisms of species divergence between sympatric species. Such information is critically important for understanding the evolutionary force of species diversity in Primulina.

生殖隔离在维持物种完整性的过程中起着重要的作用，解析植物生殖隔离性状的遗传基础，对探讨植物多样性形成和维持机制有重要意义，对濒危植物的保育具有指导意义。报春苣苔属（Primulina）是我国苦苣苔科（Gesneriaceae）物种多样性最丰富的属，大部分物种为华南喀斯特濒危植物。本研究以报春苣苔属濒危植物马坝报春苣苔（Primulina mabaensis）及其同域分布的近缘物种牛耳朵（P. eburnea）为研究材料，通过RAD-seq获得分子标记并构建高密度遗传连锁图谱，开展花粉育性和杂种种子活力等生殖隔离性状的QTL定位，阐明控制植物生殖隔离性状的基因组区域的数目、位置和效应；整合通过全基因组重测序和基因组扫描鉴定的基因组高度分化区域，揭示报春苣苔属同域分布近缘种生殖隔离的遗传基础。本研究旨在揭示报春苣苔属植物维持物种丰富度的基因组机制，为濒危珍稀植物的保育和物种恢复提供理论依据。

同域分布近缘物种往往各自进化出独特的适应性性状和生殖隔离性状，以维持其物种的完整性，解析适应性性状和生殖隔离性状的遗传基础，对理解物种形成和濒危物种的保育具有重要意义。本研究以同域分布的一对近缘种，即报春苣苔属牛耳朵（Primulina eburnea）和濒危物种马坝报春苣苔（Primulina mabaensis），为研究材料，利用高分辨率的遗传图谱对其重要的适应性性状和合子后生殖隔离性状进行QTL定位，阐明这些重要性状的QTL在基因组内的位置、数量和效应，结合基因组扫描，探讨QTL位点与基因组岛的关系。同时，本研究还开展了濒危物种遗传多样性高效评估方法和实生苗的高效繁殖方法。总的来说，本研究在一定程度上揭示了报春苣苔属植物维持物种丰富度的基因组机制，也为报春苣苔属濒危物种保育提供了技术指导