State Plant Breeding Institute, University of Hohenheim, 70593, Stuttgart, Germany.
School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Urrbrae, SA, Australia.
Plant J. 2017 Dec;92(5):892-903. doi: 10.1111/tpj.13726. Epub 2017 Nov 10.
Increases in the yield of wheat during the Green Revolution of the late 20 century were achieved through the introduction of Reduced height (Rht) dwarfing genes. The Rht-B1 and Rht-D1 loci ensured short stature by limiting the response to the growth-promoting hormone gibberellin, and are now widespread through international breeding programs. Despite this advantage, interference with the plant's response to gibberellin also triggers adverse effects for a range of important agronomic traits, and consequently modern Green Revolution genes are urgently required. In this study, we revisited the genetic control of wheat height using an association mapping approach and a large panel of 1110 worldwide winter wheat cultivars. This led to the identification of a major Rht locus on chromosome 6A, Rht24, which substantially reduces plant height alone as well as in combination with Rht-1b alleles. Remarkably, behind Rht-D1, Rht24 was the second most important locus for reduced height, explaining 15.0% of the genotypic variance and exerting an allele substitution effect of -8.8 cm. Unlike the two Rht-1b alleles, plants carrying Rht24 remain sensitive to gibberellic acid treatment. Rht24 appears in breeding programs from all countries of origin investigated, with increased frequency over the last decades, indicating that wheat breeders have actively selected for this locus. Taken together, this study reveals Rht24 as an important Rht gene of commercial relevance in worldwide wheat breeding.
20 世纪后期绿色革命期间，小麦产量的增加是通过引入矮化基因（Reduced height，Rht）实现的。Rht-B1 和 Rht-D1 基因座通过限制对生长促进激素赤霉素的反应来确保植株矮小，现在已通过国际育种计划广泛应用。尽管有这个优势，但对植物对赤霉素反应的干扰也会引发一系列重要农艺性状的不利影响，因此迫切需要现代绿色革命基因。在这项研究中，我们使用关联图谱分析方法和一个包含 1110 个全球冬小麦品种的大型面板，重新研究了小麦株高的遗传控制。这导致鉴定出 6A 染色体上的一个主要 Rht 基因座 Rht24，它单独或与 Rht-1b 等位基因结合时，可显著降低株高。值得注意的是，仅次于 Rht-D1，Rht24 是第二个对降低株高最重要的基因座，解释了 15.0%的基因型方差，并产生了-8.8cm 的等位基因替代效应。与两个 Rht-1b 等位基因不同，携带 Rht24 的植物仍然对赤霉素处理敏感。Rht24 出现在所有调查起源国的育种计划中，过去几十年的频率增加，表明小麦育种家一直在积极选择这个基因座。总之，这项研究揭示了 Rht24 是全球小麦育种中具有商业重要性的重要 Rht 基因。
