Molecular Mapping of Reduced Plant Height Gene Rht24 in Bread Wheat

Abstract

Height is an important trait related to plant architecture and yield potential in bread wheat (Triticum aestivum L.). We previously identified a major quantitative trait locus QPH.caas-6A flanked by simple sequence repeat markers Xbarc103 and Xwmc256 that reduced height by 8.0–10.4%. Here QPH.caas-6A, designated as Rht24, was confirmed using recombinant inbred lines (RILs) derived from a Jingdong 8/Aikang 58 cross. The target sequences of Xbarc103 and Xwmc256 were used as queries to BLAST against International Wheat Genome Sequence Consortium database and hit a super scaffold of approximately 208 Mb. Based on gene annotation of the scaffold, three gene-specific markers were developed to genotype the RILs, and Rht24 was narrowed to a 1.85 cM interval between TaAP2 and TaFAR. In addition, three single nucleotide polymorphism (SNP) markers linked to Rht24 were identified from SNP chip-based screening in combination with bulked segregant analysis. The allelic efficacy of Rht24 was validated in 242 elite wheat varieties using TaAP2 and TaFAR markers. These showed a significant association between genotypes and plant height. Rht24 reduced plant height by an average of 6.0–7.9 cm across environments and were significantly associated with an increased TGW of 2.0–3.4 g. The findings indicate that Rht24 is a common dwarfing gene in wheat breeding, and TaAP2 and TaFAR can be used for marker-assisted selection.

Dissection of two quantitative trait loci with pleiotropic effects on plant height and spike length linked in coupling phase on the short arm of chromosome 2D of common wheat (Triticum aestivum L.)

“…Previous studies exhibited that numerous QTL/genes controlling PHT were detected in wheat (Borner et al 2002; Gao et al 2015a, b; Peng et al 2003; Quarrie et al 2005; Singh et al 2016; Tian et al 2017). Specifically, 24 dwarfing genes ( Rht1 – Rht24 ) have been catalogued in wheat (McIntosh et al 2017).…”

A wheat dominant dwarfing line with Rht12, which reduces stem cell length and affects gibberellic acid synthesis, is a 5AL terminal deletion line

“…The introduction of semi‐dwarfing genes into wheat was a major event in the breeding of high‐yield varieties during the Green Revolution (Gale and Youssefian, ; Peng et al ., ; Silverstone and Sun, ). More than 20 Reduced Height ( Rht ) genes have been identified in wheat, and are classified into gibberellic acid (GA)‐responsive and GA‐insensitive categories reflecting the relative magnitude of their responses to the application of exogenous GAs (Chen et al ., ; Lu et al ., ; Tian et al ., ). Only several Rht genes have been cloned, all of which are GA‐insensitive (Bazhenov et al ., ; Börner et al ., ; Peng et al ., ; Wu et al ., ; Divashuk et al ., ; Li et al ., , ).…”

A modern Green Revolution gene for reduced height in wheat

“…Interestingly, another major QTL was identified on chromosome 6A, which explained 11% of the genotypic variance in this panel of cultivars. No major Rht locus had been reported on that chromosome in wheat, but more recently Rht24 was described as a novel Rht locus located on chromosome 6A and flanked by the two simple sequence repeat (SSR) markers Xwmc256 and Xbarc103 (McIntosh et al, 2017;Tian et al, 2017). A QTL for plant height on chromosome 6A has also been reported by a few QTL mapping studies (e.g.…”