玉米矮秆主效QTL qph1-4的精细定位

Fine mapping of the major QTL qph1-4 for dwarf in maize(Zea mays L.)

利用1份在玉米自交系87-1的遗传背景上综3的染色体单片段代换系(Single segment substitution line,SSSL)SSSL-Y7为试验材料,3年3点的株高表现型鉴定表明,SSSL-Y7的株高均显著矮于受体亲本87-1,且加性效应百分率均在-10%以下,推测在该SSSL内的位于第1染色体长臂上SSR分子标记umc1122附近的目标代换片段上存在可以使玉米株高致矮的主效QTL.在该SSSL与87-1杂交构建的F2分离群体中,高秆与矮秆的株数符合3∶1的分离比例,推测其矮秆表现型由1对隐性基因控制,将该基因命名为qph1-4.qph1-4基因来源于供体自交系综3,位于Bin 1.07区域,在SSR标记MPH147和umc2396之间,距两标记的遗传距离分别为1.5和0.3 cM.与qph1-4基因连锁的SSR标记还有MPH164,umc1122,MPH162,MPH9,qph1-4与之间的遗传距离分别是2.2,2.0,2.0和2.5 cM,这些SSR标记与qph1-4基因在染色体上的排列顺序为MPH164-umc1122-MPH162-MPH147-qph1-4-umc2396-MPH9.

For studying the genetic basis of plant height of maize, one dwarf chromosome single-seg- ment subsstitution line （SSSL-Y7） derived from a backcross procedure with 87 -1, as recipient, and ＇ Zong 3 ＇ as donor, was used as basic materials. The plant height of SSSL-Y7 was significantly shorter than that of the recipient parent of 87 - 1 in three different environments, and the additive effect of the dwarf gene in SSSL-Y7 was negatively smaller than ten percent of the 87 - 1. The results demonstrated that one major QTL that caused plant height dwarf might exist near the SSR marker umc1122 on the chromosome 1. The number of tall and dwarf plants in the F2 population was found to be in accordance with the theoretical 3：1 ratio. A recessive gene derived from the donor parent Zong 3 was supposed to control the dwarf of plant height. With the aid of SSR marker analyses, a new rece-ssive dwarf gene was identified, designated as qphl-4. The qphl-4 gene was located in the Bin 1.07, flanked by the SSR markers MPH147 and umc2396 with the genetic distances of 1.5 and 0.3 eM, respectively. The other linked markers include MPH164, umc1122, MPH162 and MPH9. These linked markers are in the order of MPH164-umc1122 -MPH162 -MPH147 - qphl-4 -umc2396 -MPH9.