黄瓜种子长度的遗传分析及分子标记

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287.1 cM，标记间平均距离为17.94 cM。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2.1 cM、4.3 cM，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%。

Molecular Marker and Genetic Analysis of Cucumber Seed Length

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%.