利用SNP标记定位瓠瓜果形相关性状QTLs

Mapping of QTLs for Fruit Shape Related Traits in Bottle Gourd(Lagenaria siceraria(Mol.) Standl.) Using SNP Markers

本研究以圆形的瓠瓜[Lagenaria siceraria (Mol.) Standl.]材料‘J104’和长颈瓶形的‘PS30’杂交获得的F2分离群体(204个单株)为作图群体,利用KASP技术进行SNP分子标记分型,构建遗传连锁图谱并定位瓠瓜果形相关性状QTLs。构建的遗传连锁图谱包含12个连锁群和68个SNP标记,总长度达826.30 cM,标记间平均距离为12.03 c M。结合构建的遗传连锁图谱,共检测出24个果形相关性状的QTLs,分布在第5、第6、第8、第9、第11和第12连锁群上,其中果实周长(perimeter, Pe)共检测到3个QTLs (Pe6.1, Pe9.1和Pe12.1),果实横轴线长度(width mid-height, WM-h)、果实纵轴线长度(width mid-height, HM-w)和果实长度(maximum height, MH)分别只检测到一个QTL,贡献率分别为10.93%、19.61%和22.22%。沿果形曲线长度(curved height, CH),果实趋于椭圆(ellipsoid, El),果实趋于矩形(rectangular, Re)和倒卵形(obovoid, Ob)分别检测到2、6、5、5个QTLs。分析发现本研究检测到的QTLs中存在多个位点的高度重合,因此推测可能存在一因多效或者紧密连锁的基因。本研究结果为瓠瓜果形相关性状QTLs的精细定位奠定了基础,对揭示瓠瓜复杂果形的遗传调控机制具有重要意义。

Using a(204 plants) F2 mapping population, which derived from the cross between a round-fruited bottle gourd ’J104’ and a long-handled-round-fruited bottle gourd ’PS30’, this study was conducted to construct a genetic linkage map and carry out the QTLs of fruit shape related traits in bottle gourd. The genetic linkage map covered 826.30 cM with an interval length of 12.03 cM, which included 12 linkage groups(LGs) and 68 SNP markers.A total of 24 QTLs for fruit shape were detected, which located in the LG5, 6, 8, 9 and 12, respectively. Three QTLs were detected related to Perimeter(Pe) including Pe6.1, Pe9.1 and Pe12.1. Only one QTL was detected related to Width Mid-height(WM-h), Width Mid-height(HM-w) and Maximum Height(MH) and explained 10.93%, 19.61%,22.22% of phenotype variation, respectively. Two, six, five, five QTLs were detected for Curved Height(CH), Ellipsoid(El), Rectangular(Re) and Obovoid(Ob), respectively. We further found that some QTLs were mapped to the similar region, which may contain closely linked genes or a single gene with pleiotropic effects on fruit shape.The results of our study laid the base for the further fine mapping of QTLs for fruit shape, which is significant to reveal the genetic regulation mechanism of the complex fruit shape in bottle gourd.