Hydration of the endosperm is a critical part of the malting process that ensures proper modification of the grain. However, little is known about the genetic controls of endosperm hydration and its relationship to agronomic and malt quality traits. The extent of endosperm hydration is estimated through hydration index (HYI). We measured HYI, agronomic, and malt quality traits on a 169-line subset of the NSGC Barley Core Panel, which includes global malt lines, some dating from the inception of European breeding programmes. Utilizing GWAS, 61 QTLs were identified for HYI, dormancy, agronomic, and malt quality traits. Of these, six were found to be related to HYI and were located on 1H, 2H, 3H, 6H, and 7H. We found HYI QTLs cosegregating with kernel size and hardness (1H and 3H), malting quality (2H and 6H), and dormancy (2H and 6H). These results indicate that endosperm hydration after steeping can be improved by selecting high HYI alleles on 2H, 6H, and 7H, positively impacting malting quality without negatively impacting kernel size or dormancy.

中文翻译：

---

啤酒大麦（Hordeum vulgare）胚乳水合的遗传解剖

胚乳的水合作用是麦芽制造过程的关键部分，可确保谷物的适当改性。然而，人们对胚乳水合的遗传控制及其与农艺和麦芽品质性状的关系知之甚少。胚乳水合程度通过水合指数（HYI）来估计。我们测量了 NSGC 大麦核心小组 169 个品系子集的 HYI、农艺和麦芽质量性状，其中包括全球麦芽品系，其中一些品系可以追溯到欧洲育种计划之初。利用 GWAS，鉴定了 61 个与 HYI、休眠、农艺和麦芽品质性状相关的 QTL。其中，有 6 个被发现与 HYI 有关，分别位于 1H、2H、3H、6H 和 7H。我们发现 HYI QTL 与籽粒大小和硬度（1H 和 3H）、麦芽质量（2H 和 6H）以及休眠（2H 和 6H）共分离。