一个新矮生玉米种质资源矮生性状QTL的定位

用新发现的玉米矮生种质资源矮2003×冀257构建的255个F2:3家系为作图群体, 利用114个覆盖玉米全基因组的SSR标记构建连锁图谱, 图谱总长度2 852.1 cM, 标记间平均距离为27.42 cM。2006年在北京与海南进行随机区组试验, 鉴定了255个F2:3家系成株期株高。用复合区间作图法(composite interval mapping, CIM), 对控制玉米株高性状的遗传位点进行QTL检测。在两个不同环境下均检测到相同的控制玉米株高的QTL位点3个, 分别位于第1和第2条染色体。其中在第1染色体上的1.10~1.11区段存在一个控制株高的主效QTL, 与dwarf plant8 (d8)位置相近, 在北京和海南环境下分别能够解释株高表型变异的50.5%和37.5%, 作用方式表现为显性效应。深入的序列分析结果显示, 该基因/QTL位于已知的d8基因下游20~30 cM的染色体区间, 这可能是玉米中控制株高的一个新基因。

QTL Identification for Plant Height in a New Dwarf Germplasm of Maize

Dwarf germplasm is important for both breeding programs and basic researches in maize (Zea mays L.). Previously we found a naturally occurred dwarf mutant from the inbred K36 and developed a new dwarf germplasm, Ai 2003, with good agronomical performance. Classical genetic analysis showed that this dwarfing character was controlled by a major single reces-sive nuclear gene. However, the character of plant height in the germplasm is also likely associated with other genetic loci. There-fore, quantitative tra...