QTL Mapping and Validation for Kernel Area and Circumference in Common Wheat via High-Density SNP-Based Genotyping

Abstract

As an important component, 1,000 kernel weight (TKW) plays a significant role in the formation of yield traits of wheat. Kernel size is significantly positively correlated to TKW. Although numerous loci for kernel size in wheat have been reported, our knowledge on loci for kernel area (KA) and kernel circumference (KC) remains limited. In the present study, a recombinant inbred lines (RIL) population containing 371 lines genotyped using the Wheat55K SNP array was used to map quantitative trait loci (QTLs) controlling the KA and KC in multiple environments. A total of 54 and 44 QTLs were mapped by using the biparental population or multienvironment trial module of the inclusive composite interval mapping method, respectively. Twenty-two QTLs were considered major QTLs. BLAST analysis showed that major and stable QTLs QKc.sau-6A.1 (23.12–31.64 cM on 6A) for KC and QKa.sau-6A.2 (66.00–66.57 cM on 6A) for KA were likely novel QTLs, which explained 22.25 and 20.34% of the phenotypic variation on average in the 3 year experiments, respectively. Two Kompetitive allele-specific PCR (KASP) markers, KASP-AX-109894590 and KASP-AX-109380327, were developed and tightly linked to QKc.sau-6A.1 and QKa.sau-6A.2, respectively, and the genetic effects of the different genotypes in the RIL population were successfully confirmed. Furthermore, in the interval where QKa.sau-6A.2 was located on Chinese Spring and T. Turgidum ssp. dicoccoides reference genomes, only 11 genes were found. In addition, digenic epistatic QTLs also showed a significant influence on KC and KA. Altogether, the results revealed the genetic basis of KA and KC and will be useful for the marker-assisted selection of lines with different kernel sizes, laying the foundation for the fine mapping and cloning of the gene(s) underlying the stable QTLs detected in this study.

Quantitative Trait Locus Mapping of Marsh Spot Disease Resistance in Cranberry Common Bean (Phaseolus vulgaris L.)

“…The employment of LD blocks as markers can notably decrease the possibility of false positives during multiple hypotheses in the GWAS model [ 40 ]. In this study, all 16 additive QTL were identified using three genetic map-based models ( Table 3 ), demonstrating their detection power in QTL mapping [ 44 , 45 , 46 ], whereas six of them were validated by RTM-GWAS. These results indicate that the value of using multiple models that combine the genetic map-based and GWAS models facilitates the detection of QTL with small effects and the validation of QTL.…”

Identification and Validation of a Stable Major-Effect Quantitative Trait Locus for Kernel Number per Spike on Chromosome 2D in Wheat (Triticum aestivum L.)

“…Then, the KNPS, TKW, GL, GW, and GDR were measured by an SC-G automatic seed analysis and 1000-grain weight analyzer (Wanshen, Hangzhou, China). These data were recruited from our previous studies [ 43 , 44 ]. The GY was calculated by the formula = SN × KNPS × (TKW/1000).…”

Development and Molecular Cytogenetic Characterization of a Novel Wheat-Rye T6RS.6AL Translocation Line from Secale cereale L. Qinling with Resistance to Stripe Rust and Powdery Mildew

“…Common wheat (Triticum aestivum L.) is one of the most important crops in the world and provides approximately 20% of the food in the human diet [1]. It is very important to maintain and continue increasing the yield of common wheat to relieve the pressure exerted by the decrease in farmland and the increase in the population [2]. However, stripe rust and powdery mildew, caused by Puccinia striiformis Westend.…”