Pleiotropic Effect of the compactum Gene and Its Combined Effects with Other Loci for Spike and Grain-Related Traits in Wheat

Abstract

Club wheat (Triticum aestivum ssp. compactum) with a distinctly compact spike morphology was conditioned by the dominant compactum (C) locus on chromosome 2D and resulted in a redistribution of spike yield components. The disclosure of the genetic basis of club wheat was a prerequisite for the development of widely adapted, agronomically competitive club wheat cultivars. In this study, we used a recombinant inbred line population derived from a cross between club wheat Hiller and modern cultivar Yangmai 158 to construct a genetic linkage map and identify quantitative trait loci associated with 15 morphological traits. The club allele acted in a semi-dominant manner and the C gene was mapped to 370.12–406.29 Mb physical region on the long arm of 2D. Apart from compact spikes, C exhibited a pleiotropic effect on ten other agronomic traits, including plant height, three spike-related traits and six grain-related traits. The compact spike phenotype was correlated with decreased grain size and weight, but with an increase in floret fertility and grain number. These pleiotropic effects make club wheat have compatible spike weight with a normal spike from common wheat. The genetic effects of various gene combinations of C with four yield-related genes, including Ppd-D1, Vrn-D3, Rht-B1b and Rht8, were evaluated. C had no epistatic interaction with any of these genes, indicating that their combinations would have an additive effect on other agronomically important traits. Our research provided a theoretical foundation for the potentially effective deployment of C gene into modern breeding varieties in combination with other favorable alleles.

The Dissection of Nitrogen Response Traits Using Drone Phenotyping and Dynamic Phenotypic Analysis to Explore N Responsiveness and Associated Genetic Loci in Wheat

“…Besides using static and dynamic phenotypes to study N responsiveness and N-response phenotypes, we further explored the use of dynamic phenotyping to associate genetics underlying N responsiveness. GWAS was performed using the Wheat55K SNP Array [ 57 , 70 ]. After removing low-quality markers, 44,215 SNP markers were obtained, covering 13,531.8 Mb (Table S12 and Fig.…”

Physical mapping of the wheat genes in low recombination regions: Radiation Hybrid mapping of the C-locus

“…To date, the putative location of the C-locus was identi ed as C-2DS or C-2DL (Johnson et al 2008;Yu et al 2022;Wen et al 2022). Some recent studies have also used different approaches to localize the Clocus without any consensus on a single arm of the chromosome 2D.…”

“…A limited number of mapping studies were conducted on this trait and there is no consensus about the placement of the C-locus (Johnson et al 2008;Yu et al 2022;Wen et al 2022). Johnson et al 2008, used two genetic mapping populations and placed the C-locus close to the centromeric region of chromosome 2D.…”

“…It remains uncharacterized at the molecular level, mainly due to its location in a low recombination region. The Clocus has a pleiotropic effect on many traits as it affects spike morphology, grain size, shape, number, and perhaps other aspects of plant development and directly or indirectly affects the agronomic performance of wheat such as height (Johnson et al 2008;Wen et al 2022). There is a keen interest in understanding this trait and its relationship with other spike-compacting genes in wheat and related germplasm.…”

Allelic Variations in Vernalization (Vrn) Genes in Triticum spp.

“…Vrn-3 produces a mobile protein that functions as a flowering activator [26] and, as homologous to FLOWERING LOCUS T (FT) of Arabidopsis [26,41], is induced by long days, further accelerating reproductive apex development [26,38,42]. In hexaploid wheat, the three copies of Vrn-3 (Vrn-A3, Vrn-B3, and Vrn-D3) were mapped on chromosomes 7A, 7B, and 7D, respectively [26,[43][44][45][46]. Yan et al [26] first suggested that Vrn-3 was linked to a gene similar to Arabidopsis FT; the latter was then proposed by Tamaki et al [47] as the candidate for Florigen, a locus encoding the mobile signal that induces floral initiation at the shoot apex [47].…”