Abstract:
Drought tolerance in rice is controlled by several genes and is inherited quantitatively. Low genetic map density and the use of phenotypic traits that do not reflect the corresponding tolerance level have been obstacles in genetic analyses performed to identify genes that control drought-tolerant traits in rice. The current study aimed to construct a genetic map from high-density single-nucleotide polymorphism (SNP) markers generated from genome sequences of recombinant inbred lines (RILs), derived from IR64 × Hawara Bunar. Moreover, it sought to analyze the quantitative trait loci (QTL) and identify the drought tolerance candidate genes. A linkage map along 1980 cM on the 12 rice chromosomes was constructed employing 55,205 SNP markers resulting from the RIL genome sequences. A total of 175 morpho-physiological traits pertaining to drought stress were determined. A total of 41 QTLs were detected in 13 regions on rice chromosomes 1, 3, 6, 8, 9, and 12. Moreover, three hotspot QTL regions were found on chromosomes 6 and 8, along with two major QTL on chromosome 9. Differential gene expression for the loci within the QTL physical map intervals revealed many potential candidate genes. The markers tightly linked to the QTL and their candidate genes can potentially be used for pyramiding in marker-assisted breeding in order to achieve genetic improvement concerning the tolerance of rice to drought stress.
BACKGROUND: The online version contains supplementary material available at 10.1007/s12298-021-01095-y.
摘要:
水稻的耐旱性受多个基因控制,并在数量上遗传。低遗传图谱密度和使用不反映相应耐受性水平的表型性状一直是进行遗传分析以鉴定控制水稻耐旱性性状的基因的障碍。本研究旨在从重组自交系(RIL)的基因组序列产生的高密度单核苷酸多态性(SNP)标记构建遗传图谱,源自IR64×HawaraBunar。此外,它试图分析数量性状基因座(QTL)并鉴定耐旱性候选基因。使用由RIL基因组序列产生的55,205个SNP标记,构建了沿1980cM在12个水稻染色体上的连锁图。确定了总共175个与干旱胁迫有关的形态生理性状。在水稻1、3、6、8、9和12号染色体上的13个区域共检测到41个QTLs。此外,在6号和8号染色体上发现了三个热点QTL区域,在9号染色体上发现了两个主要的QTL。QTL物理图谱间隔内基因座的差异基因表达揭示了许多潜在的候选基因。与QTL紧密连锁的标记及其候选基因可潜在地用于标记辅助育种中的金字塔化,以实现有关水稻对干旱胁迫的耐受性的遗传改进。
背景:在线版本包含补充材料,可在10.1007/s12298-021-01095-y获得。