甜瓜结实花初花节位QTL分析

 以WI998为母本（纯雌株、厚皮网纹甜瓜品系），TopMark为父本（雄全同株纯合品系），配置杂交组合，利用单粒传得到171个株系的重组自交系（F₂S₄）群体构建甜瓜SSR分子标记遗传连锁图谱。该连锁图谱包含19个连锁群，覆盖基因组长度为1 414.2 cM，标记间平均距离为10.2 cM。对结实花初花节位开展QTL分析，共检测到9个QTL，分别分布在第1、9、10、11连锁群上，各QTL的LOD值在2.89 ~ 9.42之间，4个QTL贡献率超过10%。位于第9连锁群的QTL Fp9.4贡献率最大，为18.57%（2010秋季LOD = 9.17）；位于第9连锁群的Fp9.3（2010春季8.64%，LOD = 6.44；2010秋季17.99%，LOD = 9.42），位于第10连锁群的Fp10.1（2010春季3.59%，LOD = 2.89；2010秋季6.20%，LOD = 3.43）在两季的位置都很稳定。获得与结实花初花节位紧密连锁（< 10 cM）的8个特异标记（SSR01737、MU141991、TJ105、GCM206、SSR04910、MU173563、NR52、MU146331），为进一步开展QTL精细定位提供参考。

QTL Analysis of the First Fertile Flower Node of Cucumis melo L.

he homozygous andromonoecy line TopMark served as male parent was crossed with the homozygous gynoecious line WI998 served as female parent during the experiment. The F₁ derived from WI998 × TopMark was self-pollinated by single-seed descent（SSD）to obtain 171 F₂S₄ recombinant inbred lines（RILS），which was used to construct a SSR genetic linkage map. The resulting genetic map consisted of 19 linkage groups spanning 1 414.2 cM with an average marker interval of 10.2 cM. Total 9 QTLs of the first node on fertile flower were detected using the genetic map. These QTL were mapped on linkage groups 1，9，10，11，respectively. Their LOD values varied between 2.89–9.42. Four QTLs explained phenotypic variation more than 10%. Fp9.4 which was located in the 9th linkage group explained the highest phenotypic variation was 18.57%（2010 autumn，LOD = 9.17）. Also Fp9.3 which was located in the 9th linkage group（2010 spring 8.64%，LOD = 6.44；2010 autumn 17.99%，LOD = 9.42）and Fp10.1 which was located in 10th linkage group（2010 spring 3.59%，LOD = 2.89；2010 autumn 6.20%，LOD = 3.43）were both detected in the two seasons. The eight closed linkage markers（SSR01737、MU141991、TJ105、GCM206、SSR04910、MU173563、NR52、MU146331）can be used in fine mapping of the first node on fertile flower，which provides important reference anchors to the QTL in the future.