BACKGROUND The accumulation and remobilization of stem water soluble carbohydrates (WSC) are determinant physiological traits highly influencing yield potential in wheat against drought stress. However, knowledge gains of the genetic control are still limited. A hexaploid wheat population of 120 recombinant inbred lines were developed to identify quantitative trait loci (QTLs) and to dissect the genetic basis underlying eight traits related to stem WSC under drought stress (DS) and well-watered (WW) conditions across three environments. RESULTS Analysis of variance (ANOVA) revealed larger environmental and genotypic effects on stem WSC-related traits, indicating moderate heritabilities of 0.51-0.72. A total of 95 additive and 88 pairs of epistatic QTLs were identified with significant additive and epistatic effects, as well as QTL× water environmental interaction (QEI) effects. Most of additive QTLs and additive QEIs associated with drought-stressed environments functioned genetic effects promoting pre-anthesis WSC levels and stem WSC remobilization to developing grains. Compared to other genetic components, both genetic effects were performed exclusive contributions to phenotypic variations in stem WSC-related traits. Nineteen QTL clusters were identified on chromosomes 1B, 2A, 2B, 2D, 3B, 4B, 5A, 6A, 6B and 7A, suggestive of the genetic linkage or pleiotropy. Thirteen additive QTLs were detectable repeatedly across two of the three water environments, indicating features of stable expressions. Some loci were consistent with those reported early and were further discussed. CONCLUSION Stem WSC-related traits were inherited predominantly by additive and QEI effects with a moderate heritability. QTL cluster regions were suggestive of tight linkage or pleiotropy in the inheritance of these traits. Some stable and common loci, as well as closely linked molecular markers, had great potential in marker-assisted selection to improve stem WSC-related traits in wheat, especially under drought-stressed environments.

中文翻译：

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终端干旱胁迫下小麦（Triticum aestivum L.）茎 WSC 积累和再动员的遗传剖析。

背景茎水溶性碳水化合物(WSC)的积累和再动员是高度影响小麦对抗干旱胁迫的产量潜力的决定性生理性状。然而，遗传控制的知识获取仍然有限。开发了由 120 个重组自交系组成的六倍体小麦群体，以鉴定数量性状位点 (QTL)，并剖析三种环境中干旱胁迫 (DS) 和水分充足 (WW) 条件下与茎 WSC 相关的八个性状的遗传基础。结果方差分析 (ANOVA) 显示，环境和基因型对茎 WSC 相关性状的影响较大，表明遗传力中等，为 0.51-0.72。共鉴定出95对加性QTL和88对上位QTL，具有显着的加性和上位效应，以及QTL×水环境相互作用（QEI）效应。大多数与干旱胁迫环境相关的附加 QTL 和附加 QEI 发挥遗传效应，促进开花前 WSC 水平并阻止 WSC 重新动员到发育中的谷物。与其他遗传成分相比，这两种遗传效应对茎 WSC 相关性状的表型变异有独特的贡献。在染色体 1B、2A、2B、2D、3B、4B、5A、6A、6B 和 7A 上鉴定出 19 个 QTL 簇，表明遗传连锁或多效性。在三个水环境中的两个环境中重复检测到 13 个附加 QTL，表明稳定表达的特征。一些位点与早期报道的一致，并进行了进一步讨论。结论 干 WSC 相关性状主要通过加性和 QEI 效应遗传，具有中等遗传力。QTL簇区域暗示这些性状遗传中的紧密连锁或多效性。一些稳定和共同的基因座以及紧密连锁的分子标记在标记辅助选择中具有巨大的潜力，可以改善小麦茎 WSC 相关性状，特别是在干旱胁迫环境下。