黄瓜种子长度的遗传分析及分子标记

Molecular Marker and Genetic Analysis of Cucumber Seed Length

为了今后正确制定籽用黄瓜育种方案和有效地进行品种选育,有必要对黄瓜种子大小进行详细研究。选用种子长短不同的5个黄瓜自交系作为杂交亲本,按照Griffing双列杂交试验方法Ⅱ配制杂交组合。以长种子自交系D06157和短种子自交系D0603为亲本,构建F2分离群体,采用SSR分子标记构建遗传连锁图谱,利用复合区间定位方法进行QTL定位。结果表明:黄瓜种子长度属于数量性状,以显性效应为主,同时存在加性效应,广义遗传力及狭义遗传力较低,分别为28.6777%、10.8384%。构建的4个连锁群含有16个SSR位点,连锁群总长度为287.1cM,标记间平均距离为17.94cM。检测出6个与黄瓜种子长度相关的QTL,其中QTL5和QTL6有着较高的对种子长度性状变异的解释率(>5%),距离最近标记的图距分别为2.1cM、4.3cM,LOD值分别为7.84、9.69,可解释遗传变异分别为6.07%、6.08%,加性效应值分别为39.12%、37.21%。

In order to become the correct policy with cucumber seed breeding plan and efficient variety breeding, it is necessary to study in detail the cucumber seed length. Selected 5 different seed length inbred lines and build hybrid combination according GriffingⅡ. The results showed that cucumber seed length was a quantitative trait. It took dominant effect as main character,and there were certain additive effects. The narrow-sense heritability and broad-sense heritability were 28.6777% and 10.8384% . On the basis of F2 segregating population derived from combinations of large seed D06157 and small seed D0603, a molecular marker linkage map was constructed with SSR marker, and QTL analysis was performed with composite interval mapping （CIM）. The results showed that 4 linkage groups were constructed which containing 16 SSR loci, and the total length of the linkage group was 287.1 cM, the average distance between markers was 17.94 cM. 6 QTLs was detected. Among them QTL5 and QTL6 had higher contribution rate （5% ） on seed length, the minimum distance were 2.1 cM, 4.3 cM, LOD value were 7.84, 9.69, and the contribution rate to mutation were 6.07%, 6.08%, the additive effects were 39.12%, 37.21%.