基于RAD-seq构建苦瓜高密度遗传连锁图谱及强雌基因McPG1定位

Because more male flowers and less female flowers significantly limits yield in ordinary germplasm resources of bitter gourd. Bitter gourd with relatively more female flowers is a key job in improving bitter gourd yield. On the basis of lab’s work, the strong-female line Q11-2 have been bred with large potential for increasing production and hybrid seed yield. On the basis of lab’s work, the strong-female vareties Q11-2 have been bred with large potential for increasing production and hybrid seed yield. The study on knowledge-based theory of the strong-female line in bitter gourd is rather insufficient, which has severely impacted bitter gourd using strong-female line creation and breeding process. In this study,the F6 population which were developed from a cross between strong-female line Q11-2 and strong-male line BK0604, high-density bitter gourd molecular maps were constructed through high-throughput sequencing technology, and locating the gene of strong-male line McPG1, and on this basis, F2、BC1F2 can then be futher used for fine mapping. The results of this research could provides strong theoretical basis for maker-assisted breeding and genetic improvement.

苦瓜普通种质资源雄花多、雌花少，导致苦瓜产量偏低。发掘多开雌花少开雄花的种质资源并加以利用是提高产量的关键。本项目组育成苦瓜强雌系Q11-2，显著提高了苦瓜增产潜力和制种产量。然而有关苦瓜强雌性基础理论方面的研究还很薄弱，严重影响了优良苦瓜强雌系的创制与分子育种进程。因此，本研究拟利用苦瓜强雌系Q11-2和强雄系BK0604杂交构建的F6群体，通过高通量测序技术构建苦瓜高密度遗传连锁图谱，对强雌基因McPG1进行定位，在此基础上，进一步利用F2、BC1F2分离群体进行基因精细定位，为苦瓜强雌性分子标记辅助育种及遗传改良提供理论依据。

苦瓜普通种质资源雄花多、雌花少，导致苦瓜产量偏低。发掘多开雌花少开雄花的种质资源并加以利用是提高产量的关键。本项目组育成苦瓜强雌系Q11-2，显著提高了苦瓜增产潜力和制种产量。然而有关苦瓜强雌性基础理论方面的研究还很薄弱，严重影响了优良苦瓜强雌系的创制与分子育种进程。本研究拟利用苦瓜强雌系Q11-2和强雄系BK0604杂交构建的重组自交系（RIL）群体，通过高通量测序技术构建苦瓜高密度遗传连锁图谱，对强雌基因McPG1进行定位。在此基础上，进一步利用F2、BC1F2分离群体进行基因精细定位，为苦瓜强雌性分子标记辅助育种及遗传改良提供理论依据。本项目的结论如下：.1、利用苦瓜强雌系Q11-2、强雄系BK0604以及杂交构建的201个F6单株，基于全基因组重测序对203份苦瓜材料进行测序，构建了一张高密度的苦瓜遗传连锁图谱，遗传图谱包括由2684个标记组成的11个连锁群，覆盖基因组长度3004.92 cM，平均间距1.12 cM/marker。.2、获得苦瓜强雌基因连锁的分子标记，完成苦瓜强雌基因McPG1的定位，雌花节率符合正态分布，LOD值为2.5时，雌花节率初步定位在第2号和第8号连锁群上。通过进一步分析，将雌花节率定位在第8号连锁群上，位置在468 cM，在bin1967和bin1064之间，距离bin1967 6.06 cM、距离bin1064 1.78 cM，贡献率为7.3689，加性效应为-5.3714，这说明，控制雌花节率的效应主要来自父本。