不同供氮水平下玉米株型相关性状的QTLs定位和上位性效应分析

Mapping QTLs and Epistasis for Plant Type Traits in Maize Under Two Nitrogen Levels

用自交系Mo17与黄早四构建的RIL群体239个株系及双亲为研究材料,在高氮(施N300kg/hm2)和低氮(不施N)条件下,测定株高、穗位高、单株总叶数、穗位叶长、穗位叶宽和穗位叶面积等株型相关性状。采用QTLMapper1-6统计软件检测控制这些性状的加性效应QTLs和加性×加性上位性QTLs,共检测到19个加性效应QTLs和14对上位性QTLs,定位在玉米所有染色体上,其中1个加性效应QTL控制株高;3个加性效应QTLs和3对上位性效应控制穗位高;4个加性效应QTLs和3对上位性效应与单株总叶数有关;有4个加性效应QTLs和3对上位性效应影响穗位叶长;2个加性效应QTLs和3对上位性效应控制穗位叶宽;5个加性效应QTLs和2对上位性效应控制穗位叶面积。对应用分子标记辅助育种选育玉米株型的可能性进行了讨论。

A RIL population consisting of 239 families derived from the cross of Mo17 x Huangzaosi and their parents,was used to construct the molecular marker linkage map and detect QTLs relevant to the traits of plant type of maize（Zea mays L.） under two N-levels. Employing nitrogen by 300 kg/ha and no nitrogen was defined as the high and low N-level correspondingly in the experiment. QTLs mapping was conducted by the software QTL mapper 1-6. Under different N-levels, six traits related to plant type including plant height, ear position, leaves per plant, and leaf length, width, leaf area at ear position were measured, respectively. Nineteen QTLs with additive effects and fourteen QTL with epistatic effects in total were located on the genome of maize, in which only one QTL with additive effects is related to plant height. There are three QTL with additive effects and three QTL with epistatic effects for ear position, four QTL with additive effects and three QTL with epistatic effects for leaf number per plant, four QTL with additive effects and three QTL with epistatic effects for length of ear leaf, four QTLs with additive effects and three QTL with epistatic effects for width of ear leaf, five QTL with additive effects and two QTL with epistatic effects for leaf area at ear position, respectively. With these results the probability, strategy, and methods of markers assisted selection in maize germplasm improvement were discussed.