甜瓜种子相关性状遗传规律与QTL分析

以遗传性状差异较大的厚皮甜瓜ms-5与薄皮甜瓜HM1-1为亲本配制杂交组合,利用F_2∶3群体对种子相关性状进行主基因+多基因遗传模型分析,确定遗传规律,并构建遗传图谱对种子相关性状进行QTL分析。基因定位结果显示:甜瓜种皮颜色为1对基因控制的质量性状,白色对黄色显性;甜瓜百粒重和种子宽度符合A-1遗传模型,即1对主基因控制的加性-显性效应的数量性状;甜瓜种子长度符合B-1模型,即2对基因控制的加性-显性多基因数量性状。利用F₂群体构建1个含有153个酶切扩增多态性序列(CAPS)标记的遗传连锁图谱,该连锁图谱覆盖总长度为1 104.2 cM,标记间平均遗传距离为7.2 cM。对甜瓜种皮颜色开展初步定位,将控制甜瓜种皮颜色的白色基因(WT)定位在第5连锁群上,两端连锁标记为HD0520和HD0519,与连锁标记的遗传距离分别为13.3 cM和7.0 cM。甜瓜种子百粒重QTL位点位于第6和第11连锁群,sw6.1位于标记E0615和E0618之间,sw11.1位于标记E1113和P1117之间。甜瓜种子长度QTL分布在第7和11连锁群,sl7.1位于标记E0716和HD0713之间,sl11.1和sl11.2分别位于标记E1110、E1112及标记XB1114、E1113之间。甜瓜种子宽度QTL位点位于第2连锁群,位于标记XB0207和E0219之间。研究结果可为甜瓜种子性状的基因精细定位与克隆提供理论依据。

Genetic and QTL analysis of seed traits in melon (Cucumis melon L.)

Crossing of F_2∶3 was made from cantaloupe ms5 and muskmelon HM1-1 as parental to study the genetic inheritance of seed related traits by Major Gene and Poly-gene Genetic Model, and genetic map and QTL analysis were conducted by F_2∶3 families. The results indicated that seed coat color (SCC) was controlled by a single dominance gene, and white dominated to yellow. 100 seed weight (SW) and seed diameter (SD) were quantitative traits fit for the A-1 model, which was under one additive-dominance single major gene control. Seed length (SL) fitted the B-1 model, which was controlled by two additive-dominance major genes. By using F₂ generation, a genetic map containing 153 CAPS (cleaved amplified polymorphism suquences) markers was constructed, which covered 1 104.2 cM in melon genome, and the average genetic distance was 7.2 cM. The SCC gene was mapped on the 5 linkage group, and the interval makers were HD0520 and HD0519 with the distance of 13.3 cM and 7.0 cM, respectively. SW was mapped on the linkage group 6 and 11, with sw6.1 linked to E0615 and E0618, and sw11.1 linked to E1113 and P1117. SL located on the linkage group 7 and 11, with sl7.1 linked to E0716 and HD0713, and sl11.1 and sl11.2 linked to makers E1110 and E1112, XB1114 and E1113, respectively. SD was linked to makers XB0207 and E0219 on the linkage group 2. The results would provide theoretical basis for gene fine mapping on seed related traits and gene clone.