玉米雄穗颜色QTL分析

雄穗是玉米的重要生殖器官,不同品种间玉米的雄穗外观差异明显。对玉米雄穗的颜色进行遗传分析和QTL定位,筛选与雄穗颜色紧密连锁的分子标记,可以作为玉米的品种保护和品种鉴别的有用工具。同时,紫色雄穗中花色苷类色素含量较高,与玉米雄穗的抗虫性密切相关。本研究利用一个黑玉米自交系SDM为共同父本,分别与白玉米自交系木6和黄玉米自交系Mo17杂交,构建2个相关F2∶3群体,分别命名为MuS(木6×SDM)和MoS(Mo17×SDM),在云南和重庆两个不同的环境中种植,对玉米花药颜色(COAn)和花药护颖颜色(COCa)2个性状进行QTL定位。结果表明:玉米花药和花药护颖的颜色均为数量性状,受主效基因和微效基因共同控制。2个群体在2个环境中共检测到7个与花药颜色相关的QTL,位于第2、3、6和10染色体上,其中位于第10染色体标记区间umc1196a-IDP8526内的QTL在重庆和云南同时表达,对表型的贡献率分别为23.17%和19.98%;2个群体在2个环境中共检测到9个与花药护颖颜色相关的QTL,位于第3、6、9和10染色体上,其中3个QTL为环境钝感QTL(在2个环境中均表达,且至少在1个环境中贡献率大于10%),分别位于第6染色体标记区间umc1979-umc1796、mmc0523-umc2006内和第10染色体标记区间umc1196a-umc2043内,对表型的贡献率为10.69%～59.30%。2个群体检测到的主效QTL的位置和效应高度一致,且控制花药颜色和花药护颖颜色2个性状的主效QTL有连锁分布的现象,主要表现在bins 6.04处的标记mmc0523和bins 10.04处的标记IDP8526附近。位于第6和第10染色体上的在不同环境和遗传背景下稳定的QTL可以作为进一步精细定位的靶位点,也可以为玉米雄穗颜色的分子标记辅助选择提供有价值的参考。

Identification of QTL for Tassel Color in Maize

Abstract: tassel is an important reproductive organ of maize and the appearance of different kinds of maize differ in thousands of ways .molecular markers, tightly linked with tassel color, could be screened by genetic analysis and QTL mapping of the color of the maize tassel. these molecular markers can be used as an useful tool for maize variety protection and species identification. Mean while, higher pigment content of anthocyan in purple tassel is closely related to the insect resistance of maize tassel. In this study, a black SDM of maize inbred lines were used as a common male parent and respectively hybrid with the white maize inbred lines of wood and yellow maize inbred line Mo17 to build two F2: 3 groups, respectively named MuS (Mu6 x SDM), and MoS (, Mo17 ?SDM).these two groups were planted in two different environments in Yunnan and Chongqing, then conduct QTL mapping about two traits, the anther color (COAn) and the anther capes color (COCa). The results showed that: the anther color and the anther cape color are both quantitative traits, jointly controlled by major genes and minor genes. Seven QTL related to anther color are detected from the two groups in two different environments. They are located in chromosome 2,3,6 and 10.The QTL within marker interval umc1196a-IDP8526 on the chromosome 10 both expressed in Chongqing and Yunnan, and the contribution rate of the phenotype were 23.17% and 19.98%; nine QTL related to anther cape color are detected from the two groups in two environments, located in chromosome 3, 6, 9 and 10 .Among them, three QTL are environmental insensitive (they express in both two environments and the contribution rate are greater than 10%), which respectively in the marker interval umc1979-umc1796 mmc0523-umc2006 in chromosome 6 and the marker interval umc1196a-umc2043 in the chromosome 10 and the contribution rate of the phenotype ranges from 10.69% to 59.30%. The location and effect of the major QTL detected from these two groups have a high degree of consistency, and the major QTL controlling the two traits of anther color and anther cape color have the phenomenon of chain of distribution, mainly near the marker mmc0523 at bin6.04 and the marker IDP8526 at bin10.04. QTL that located on chromosome 6 and 10, and that are stable in different environments and genetic backgrounds can be regarded as the target sites used for further fine mapping. They can also provide a valuable reference for marker-assisted selection of maize tassel color.