甜瓜果实相关性状QTL分析

以美国厚皮甜瓜品系ms-5为母本,中国薄皮甜瓜品系HM-1为父本,配置杂交组合,构建含有189个单株的F2:3群体,对两亲本高通量重测序开发CAPS标记,构建包含159个标记、12个连锁群的遗传连锁图谱,该图谱覆盖基因组长度为1 771.53 cM,标记间平均距离为11.35 cM。应用复合区间作图法对甜瓜果实单果重、果实长、宽、果形指数、果肉厚度作QTL分析,共检测到与果实性状相关QTL位点18个,分布在第2、4、5、6和7染色体上,LOD值为2.82~18.78,可解释2.68%~79.40%表型变异率。检测到7个与果形指数相关QTL位点,分别为FS2.1、FS4.1、FS6.1、FS6.2、FS7.1、FS7.2、FS7.3,果形指数QTL位点FS6.1位于B0610和E0623两个标记之间,两标记间遗传距离为0.27 cM,LOD值为6.14,解释5.72%表型变异率,通过基因序列比对QTL FS6.1位于甜瓜基因组scaffold00027上,基因注释结果发现,该区域有26个候选基因。

Mapping of QTL for fruit traits in melon

F2∶3 population consisted of 189 individuals was constructed by the crossing of two parental materials,the American melon line ms-5 and the Chinese melon line HM-1.The parental materials were re-sequenced for CAPS markers development.A genetic linkage map consisting of 159 CAPS markers and 12 linkage groups covering the genome length of 1 771.53 cM with the average distance between two markers was 11.35 cM.The QTLs of fruit weight,fruit length,width,fruit shape index and fruit thickness were analyzed by composite interval mapping method,and totally 18 QTLs associated with the above fruit traits were detected which distributed among 7 chromosomes.The LOD values ranged from 2.82 to 18.78,which could explain the phenotypic variability of 2.68％-79.40％.Seven QTLs were detected for FS2.1,FS4.1,FS6.1,FS6.2,FS7.1,FS7.2 and FS7.3,and the fruit shape index QTL (FS 6.1) was located between CAPS marker B0610 And E0623,the genetic distance between the two markers was 0.27 cM with the LOD value of 6.14,which explained 5.72％ of the phenotypic variation.By gene alignment,QTL FS6.1 was located in the Scaffold00027 of the melon genome and 26 candidate genes were detected in this region.