Molecular dissection of plant height QTLs using recombinant inbred lines from hybrids between common wheat (Triticum aestivum L.) and spelt wheat (Triticum spelta L.)

Abstract

In wheat, plant height is an important agronomic trait, and a number of quantitative trait loci (QTLs) controlling plant height have been located. In this study, using the conditional and unconditional QTL mapping methods, combined with data from five different growth stages over two years of field trials, the developmental behavior for plant height in wheat was dissected. Nine unconditional QTLs and 8 conditional QTLs were identified, of which 6 were detected by both methods. None of the 11 QTLs was detected at all of the 5 investigated developmental stages, but 7 QTLs were detected at certain stages in both years. Further analysis identified 9 unconditional QTLs at different stages, which could explain the phenotypic variation from 4.81% to 17.35%. It was noteworthy that one major QTL designated QHt-4B-2, which was located on chromosome 4B, was detected on May 18 and 25 in both years, and its genetic contributions to plant height ranged from 13.42% to 16.13%. Moreover, of the 8 conditional QTLs identified, six were detected in both years, in the order of QHt-3B→QHt-4B-1→QHt-4B-2→QHt-4D→QHt-5A and QHt-2B expressed at the same developmental stage. The results indicate that QTL expression during plant height development is selective and in a temporal order. As one of the most important agronomic traits in wheat breeding, plant height plays a vital role in producing plants with high lodging resistance and high harvest index. For example, the dwarfism gene from Nonglin-10, which was widely used in classical wheat breeding programs, contributed significantly to the green revolution in the 1960s [1]. Until now, dwarfism breeding has been important in increasing the yield of wheat all over the world. Genetic analysis of plant height has been carried out by many researchers, and more than 20 dwarfism genes have been identified in wheat [2]. Some of these genes have been *Corresponding authors (email: penghuiru@cau.edu.cn; qxsun@cau.edu.cn) exploited to breed many semidwarf cultivars with high yield potential. Recently, along with the advent of molecular quantitative genetics, about 50 quantitative trait loci (QTLs) for wheat plant height have been identified using the constructed molecular genetic linkage maps [3][4][5][6][7][8][9][10][11][12][13][14][15]. However, QTL mapping of plant height in wheat was only focused on the performance of this trait at the maturing stage.Conventional statistical genetic analysis revealed that gene expression patterns were distinct at different developmental stages, and the genetic model for the final character did not fully reflect the true gene expression pattern during formation of the character [16][17][18][19][20][21][22]. Therefore it is necessary to conduct dynamic mapping of plant height at a variety of

Molecular Mapping of Reduced Plant Height Gene Rht24 in Bread Wheat

“…Among them, only four homeologous genes Rht1 ( Rht-B1b ), Rht2 ( Rht-D1b ), Rht3 ( Rht-B1c ), and Rht10 ( Rht-D1c ) from the chromosome 4BS, 4DS, 4BS, and 4DS, respectively, had been cloned ( Peng et al, 1999 ; Pearce et al, 2011 ; Wu et al, 2011 ), 13 were on chromosomes 2AS (2), 2BL (1), 2DL (1), 3BS (1), 5AL (1), 5DL (1), 6AS (3), 7AS (1), and 7BS (2), but the locations of six other dwarfing genes have not been determined yet ( Peng et al, 1999 , 2011 ; Ellis et al, 2005 ; Wu et al, 2011 ; McIntosh et al, 2013 ; Chen et al, 2015 ). So far, more than 50 quantitative trait loci (QTL) for plant height have also been identified on all wheat chromosomes in previous reports ( Börner et al, 2002 ; Peng et al, 2003 ; Quarrie et al, 2005 ; Liu et al, 2011 ; Griffiths et al, 2012 ; Würschum et al, 2015 ). For example, Wei et al (2010) identified quite a few stable plant height QTL located on chromosomes 2A, 2B, 2D, 3B, 4B, 5A, 5D, 7B, and 7D.…”

Dissection of Superior Alleles for Yield-Related Traits and Their Distribution in Important Cultivars of Wheat by Association Mapping

“…McCartney et al (2005) also reported an SSR locus, Xgwm333, linked to PH on 7B at position 475.6 Mb. In addition, Huang et al (2003) and Liu et al (2011) also detected different QTLs related to PH on 7B. Similarly, 14, 9, and 9 superior alleles associated with GWS, TSNS and SNPP, respectively, were found in our study, of which three (AX-110630537, AX-110586945, and AX-95009966 on 4A, 5B, and 6D, respectively), one (AX-111541781 on 5B), and one (AX-110142073 on 3B) may have corresponded to previously mapped QTL regions because they had similar chromosome locations ( Table 1).…”

О РЕЗУЛЬТАТАХ СЕЛЕКЦИИ ПШЕНИЦЫ СПЕЛЬТА (Triticum spelta L.) НА ПРОДУКТИВНОСТЬ И КАЧЕСТВО ЗЕРНА

“…В связи с этим спельта не может конкурировать с пшеницей мягкой (3,13). Актуальная задача селекции спельты -повышение продуктивности при сохранении высокого содержания белка и клейковины в зерне (14,15). Скрещивая T. spelta с T. aestivum, можно получить новые гибридные формы с улучшенными качественными показателями.…”