水稻中脉缺陷突变体dl-6的遗传分析与精细定位

摘要

To clone the DL-6 locus,positive and negative cross combinations were developed between dl-6 and 9311,and genetic analysis found that drooping leaf was controlled by one recessive nuclear gene DL-6. DL-6 was primarily mapped on the short arm of chromosome 3 with SSR markers. With newly developed markers DL-6 was fi-nally fine mapped in 85 kb region between markers I3-5 and I3-8 . Open reading frame ( ORF ) analysis revealed that ORF9 might be a drooping leaf related gene. ORF9 both in mutant dl-6 and in wild type were sequenced and 1 bp mutation was found in first exon in dl-6 when blasted with Nipponbare. Cysteine mutated into arginine in dl-6. Meanwhile,8 bp deletion was also found at 3′end of YABBY . These two mutations which one is the functional mu-tation of DL-6 is still uncertain and need deeply research.%为了克隆DL-6基因,以dl-6与9311配制正反杂交组合进行性状分析发现,dl-6突变性状受1对隐性核基因控制,利用SSR分子标记将控制dl-6性状的基因DL-6初步定位在水稻第3染色体的短臂上,进一步利用新发展的InDel标记将DL-6基因精细定位在I3-5和I3-8之间85 kb的物理距离内。对该区段内存在的开放阅读框( ORF)进行分析,发现其中ORF9编码的YABBY基因是一个与叶脉发育相关的基因,对突变体dl-6和野生型中YABBY基因进行测序,将测序结果与数据中日本晴序列进行比对发现,突变体dl-6中YABBY基因的第1个外显子存在1个单碱基突变,该突变导致野生型中编码的半胱氨酸突变为突变体中的精氨酸；同时突变体dl-6在YABBY基因的3′端还存在8个碱基的缺失。这2个突变位点哪个是导致dl-6突变的功能区目前还不确定,有待进一步研究。