玉米籽粒生理成熟后自然脱水速率QTL的初步定位

Primary Mapping of QTL for Dehydration Rate of Maize Kernel after Physiological Maturing

以吉846(脱水快,1.18%d-1)和掖3189(脱水慢,0.39%d-1)为亲本衍生出的232个重组自交系(F7)为作图群体,构建了具有101个SSR标记位点的玉米遗传连锁图谱,覆盖玉米基因组1941.7cM,标记间平均距离为19.22cM。通过1年2点试验(双城和哈尔滨,2007年)评价了232个重组自交系籽粒生理成熟后的自然脱水速率。采用WinQTL2.5对该性状数量性状位点(QTL)进行了初步定位和遗传效应分析,结果共检测出9个显著影响玉米籽粒生理成熟后自然脱水速率的QTL,分别位于第2、第3、第4、第5和第6染色体上,加性增效作用均来源于亲本吉846。其中在第2和第6染色体上的2个QTL(qKdr-2-1和qKdr-6-1)在2个环境下均稳定表达,分别位于SSR标记bnlg198～umc1516之间和phi126～phi077之间,其累积表型贡献率为15.49%。具有较快脱水速率的等位基因均来自吉846。所检测到的QTL将在分子辅助选育具有较快脱水速率的材料中具有较大的应用潜力。

The aim of this study was to identify QTL for dehydration rate of maize kernel after physiological maturing using 232 recombinant inbred lines derived from a cross between line Ji 846 （more faster kernel dehydration rate, 1.18% d^-1） and line Ye 3189 （more slower kernel dehydration rate, 0.39% d^-1）. Dehydration rate of maize kernel of this population and two parents were evaluated according to the method of Wang et al. （2001） and Jin et al. （1997） at tested locations Shuangcheng and Harbin in 2007, respectively. A molecular genetic map including 10 linkage groups was constructed, covering 1 941.7 cM with mean distance 19.22 cM using 101 SSR markers. A total of nine QTLs were identified through software WinQTL2.5, which were located on chromosomes 2, 3, 4, 5, and 6, respectively. Additive effect of these QTLs was derived from line Ji846. Of them, two QTLs （qKdr-2-1 located in bnlg198-umc1516 of chromosomes 2, qKdr-6-1 located in phi126-phi077 of chromosomes 6） were repeatedly found in two environments, which explained 15.49% of total phenotypic variation. Since beneficial alleles were from line Ji846, it was concluded that these QTLs would have the greatest potential value for marker assisted selection for high kernel dehydration rate of maize after physiological maturing.