水稻苗期模拟干旱胁迫条件下表型性状QTL定位

以耐旱性差异较大的两个亲本珍汕97B（ZS97B）和IRAT109构建的重组自交系（RIL）为试验材料,在正常水分条件和干旱胁迫浓度为18%的聚乙二醇-6000（PEG-6000）模拟干旱]条件对水稻苗期苗高、根长、苗高生长速率、根长苗高比、叶卷曲进行QTL定位分析,共检测到24个相关的QTL,贡献率变幅在7.35%~39.30%。其中正常条件下检测到13个相关的QTL位点,分布在第1、2、3、5、6、10、12染色体上;干旱胁迫条件下检测到11个相关的QTL位点,分布在第1、3、5、7、10、12染色体上。2种条件下检测到的QTL位点差异很大,表明不同处理条件下相关性状的遗传机制不同。此外,在第1染色体上的RM472~RM104存在控制苗高、苗高生长速率、根长、根长苗高比多个性状的QTL,并且此区间在2种处理条件下能重复检测到控制苗高位点。

QTL Mapping of Phenotypic Traits under Drought Stress Simulated by PEG-6000 in Rice Seedlings

A recombination inbred line (RIL) population with 159 lines derived from Zhengshan97B (ZS97B) and IRAT109 were treated with normal water condition and 18% polyethylene glycol (PEG-6000). Five traits including seedling height, root length, seedling height growth rate, root length seedling height ratio and leaf rolling score were measured and further used for QTL analysis. A total of 24 QTLs were detected and each locus explained 7.35%-39.30% of phenotypic variance.13 QTLs were detected on chromosomes 1, 2, 3, 5, 6, 10 and 12 under normal water condition, while 11 QTLs on chromosomes 1, 3, 5, 7, 10 and 12 under drought stress were detected. The QTLs detected under two treatments showed significant differences, which there was different genetic mechanisms controlling rice phenotypes under two different conditions. Furthermore important QTLs for many seedling traits were detected between RM472 and RM104 on chromosome 1, and this interval contained QTL for seedling height under both two different water conditions simultaneously.