Abstract:

A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F2 individuals from the cross, Huangzao 4×Ye 107. The 184 F3 families were evaluated in the field under well-watered and drought-stressed regimes in Shanxi Province of China. The objectives of the study were to identify genetic segments responsible for the expression of anthesis-silking interval (ASI), ear setting and grain yield, and to examine if the quantitative trait loci (QTLs) for ASI or yield components can be used in marker-assisted selection (MAS) to improve grain yield under drought conditions. Results showed that under well-watered and drought-stressed regimes, three and two QTLs involved in the expression of ASI were detected on chromosomes 1, 2 and 3, and 2 and 5, respectively. Under well-watered regime, two QTLs for ear setting were detected on chromosomes 3 and 6, explaining about 19.9% of the phenotypic variance, and displayed additive and partial dominant effects, respectively. Under drought-stressed condition, four QTLs for ear setting were detected on chromosomes 3, 7 and 10, which were responsible for interpreting 60.4% of the phenotypic variance, and showed dominant or partial dominant effects. Under well-watered condition, four QTLs controlling grain yield were identified on chro-mosomes 3, 6 and 7, while five QTLs were identified under drought stress on chromosomes 1, 2, 4 and 8. The gene action was of additive or partial dominant effects, and each QTL could explain 7.3% to 22.0% of the phenotypic variance, respectively. Under drought conditions, ASI and ear setting percentage were highly correlated with grain yield, which can be used as secondary traits for grain yield selection. Based on linked markers detected and gene action analyzed, an MAS strategy for yield improvement under drought condition could be established, which consists of QTLs contributing to decreased ASI and to increased ear setting and grain yield, respectively.

玉米雌雄开花间隔天数、结穗率与产量的数量性状位点(QTL)分析
李新海 刘贤德 李明顺 张世煌
(中国农业科学院作物育种栽培研究所，农业部作物遗传育种重点开放实验室，北京 100081)

摘要: 采用SSR标记连锁图谱和复合区间作图法在山西灌溉和干旱胁迫条件下，对玉米(Zea mays L.)自交系黄早四×掖107 组合的F3 群体雌雄开花间隔天数(ASI)、结穗率和籽粒产量进行了数量性状位点（QTL）定位及基因效应分析。结果表明，在两种水分处理下，ASI、结穗率与籽粒产量的相关性均达到显著水平( P ＜0.05)。 在灌溉和干旱胁迫下，分别检测到3个和2个控制ASI的QTL，位于第1、2、3和第2、5染色体上。在灌溉条件下，在第3和第6染色体上各检测到1个控制结穗率的QTL，基因作用方式呈加性或部分显性，可解释19.9%的表型变异；在干旱条件下，在第3、7、10染色体上共检测到4个控制结穗率的QTL，基因作用方式为显性或部分显性，可解释60.4%的表型变异。在灌溉和干旱胁迫下，控制产量的QTL分别定位在第3、6、7和第1、2、4、8染色体上，基因作用方式均以加性或部分显性为主，可解释的表型变异7.3~22.0%。在干旱条件下，借助连锁分子标记和基因效应分析，可构建包含ASI、结穗率和产量QTL的选择指数，用于分子标记辅助育种。
关键词: 玉米；干旱；雌雄开花间隔天数；结穗率；籽粒产量；数量性状位点(QTL)

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