Effect of Flowering Time-Related Genes on Biomass, Harvest Index, and Grain Yield in CIMMYT Elite Spring Bread Wheat

Abstract

Grain yield (YLD) is a function of the total biomass (BM) and of partitioning the biomass by grains, i.e., the harvest index (HI). The most critical developmental stage for their determination is the flowering time, which mainly depends on the vernalization requirement (Vrn) and photoperiod sensitivity genes (Ppd) loci. Allelic variants at the Vrn, Ppd, and earliness per se (Eps) genes of elite spring wheat genotypes included in High Biomass Association Panel (HiBAP) I and II were used to estimate their effects on the phenological stages BM, HI, and YLD. Each panel was grown for two consecutive years in Northwest Mexico. Spring alleles at Vrn-1 had the largest effect on shortening the time to anthesis, and the Ppd-insensitive allele Ppd-D1a had the most significant positive effect on YLD in both panels. In addition, alleles at TaTOE-B1 and TaFT3-B1 promoted between 3.8% and 7.6% higher YLD and 4.2% and 10.2% higher HI in HiBAP I and II, respectively. When the possible effects of the TaTOE-B1 and TaFT3-B1 alleles on the sink and source traits were explored, the favorable allele at TaTOE-B1 showed positive effects on several sink traits mainly related to grain number. The favorable alleles at TaFT3-B1 followed a different pattern, with positive effects on the traits related to grain weight. The results of this study expanded the wheat breeders’ toolbox in the quest to breed better-adapted and higher-yielding wheat cultivars.

A wiring diagram to integrate physiological traits of wheat yield potential

“…Deployments of these genes have been largely optimized through conventional breeding of winter and spring wheats because of their sizeable and largely heritable phenotypic effects. However, since phenotypes associated with major genes show interaction with genetic background and environment (albeit less than that seen for the combined effect of many minor genes), their deployment in breeding can require 'retuning' to optimize expression of phenology and harvest index 43 . These genes can be mapped to the WD based on previous studies with isogenic lines 42,44 .…”

Iron and zinc micronutrients and soil inoculation of Trichoderma harzianum enhance wheat grain quality and yield

“…Phenological traits including days to heading (DH), days to physiological maturity (PM), spike length (SPL), seeds per spike (SPS), and grain mass (GM) were recorded as discussed in Afzal et al ( 2018 ). Biomass and harvest index of the experimental plant material was also determined as described in Dreisigacker et al ( 2021 ).…”

Long-Amplicon Single-Molecule Sequencing Reveals Novel, Trait-Associated Variants of VERNALIZATION1 Homoeologs in Hexaploid Wheat

“…Cultivars carrying SVs within VRN1 genes showed association with many traits such as lower grain yield, biomass and harvest index compared to those with intact genes. It also has been described before that VRN1 polymorphism is associated with vernalization response, grain yield, spikelet number per spike, spike development, thousand grain weight, stem elongation, heading date, NRI and other developmental traits (Kamran et al, 2013(Kamran et al, , 2014Zheng et al, 2013;Zhang et al, 2014;Voss-Fels et al, 2018;Li et al, 2019;Chumanova et al, 2020;Dreisigacker et al, 2021;Sheoran et al, 2022). Analysis of SV spring alleles together with novel SV alleles revealed correlations with seven traits which have not been evaluated before, e.g., powdery mildew infection, kernels per m 2 , falling number, RUE, NUE, RIE and GCD.…”

“…Comparison of the number of VRN-A1 copies estimated by Würschum et al (2015) by TaqMan assay qPCR with the number of haplotypes extracted from long reads in this study, revealed in contradiction that most cultivars with three copies contained two haplotypes, while the vast majority of cultivars with two copies contained four haplotypes ( Table 4 ). Díaz et al (2012) and other authors including ( Zhu et al, 2014 ; Kippes et al, 2015 ; Würschum et al, 2015 ; Guedira et al, 2016 ; Dixon et al, 2019 ; Muterko and Salina, 2019 ; Dreisigacker et al, 2021 ; Strejčková et al, 2021 ) measured average fold-change ratio between the target gene VRN-A1 relative to the internal positive control gene CONSTANS2 (probes and primers binding to three homoeologous genes on 6A, 6B, and 6D). Thus, a ratio of 0.33 would represent one copy, 0.66 would represent two copies, 1.0 would represent 3 copies, and 1.3 would represent four copies.…”