Hybrid Seed Set in Relation with Male Floral Traits, Estimation of Heterosis and Combining Abilities for Yield and Its Components in Wheat (Triticum aestivum L.)

Abstract

Breeding hybrids with maximum heterosis requires efficient cross-pollination and an improved male sterility system. Renewed efforts have been made to dissect the phenotypic variation and genetic basis of hybrid floral traits, although the potential of tailoring the appropriate flower design on seed setting is less known. To this end, elite wheat genotypes were crossed using a chemical hybridizing agent at different doses. A total of 23 hybrids were developed from a partial diallel design; and planted in an alpha lattice design with their parents at two locations in Morocco, for two years, to evaluate for yield components, heterosis and combining abilities. The 13.5 L ha−1 dose induced a maximum level of sterility (95%) and seed set showed large phenotypic variation and high heritability. In parallel, seed set showed tight correlation with pollen mass (0.97), visual anther extrusion (0.94) and pollen shedding (0.91) (p < 0.001), allowing direct selection of the associated traits. Using the combined data, mid-parent heterosis ranges were −7.64–14.55% for biomass (BM), −8.34–12.51% for thousand kernel weight (TKW) and −5.29–26.65% for grain yield (YLD); while best-parent heterosis showed ranges of −11.18–7.20%, −11.35–11.26% and −8.27–24.04% for BM, TKW and YLD, respectively. The magnitude of general combining ability (GCA) variance was greater than the specific combining ability (SCA) variance suggesting a greater additive gene action for BM, TKW and YLD. The favorable GCA estimates showed a simple method to predict additive effects contributing to high heterosis and thus could be an effective approach for the selection of promising parents in early generations.

First insights into the quantitative genetic composition of the female seed yield for an efficient hybrid seed production in wheat (Triticum aestivum L.)

“…Therefore, both parents should contain fundamental traits, which support outcrossing and help to increase the hybrid seed yield on the female parent (Selva et al, 2020). Previous research has mainly focused on the optimization of the relevant traits for the male ideotype (Boeven et al, 2018; El Hanafi et al, 2022; Sade et al, 2022). In contrast, information about the properties of excellent female lines are little, while their routine large‐scale assessment in breeding programmes is usually discarded, because of being difficult to measure and time consuming (Langer et al, 2014; Millan‐Blanquez et al, 2022).…”

Hybrid Rice Production: A Worldwide Review of Floral Traits and Breeding Technology, with Special Emphasis on China

“…Through the application of advanced precise phenotypic methods and modern biotechnological approaches such as QTL mapping and genome-wide association studies (GWAS), significant progress has been achieved in discovering chromosomal regions that are appropriate for enabling direct and indirect selection of linked hybrid potential characteristics [ 69 ]. Therefore, it has been demonstrated that anther extrusion and pollen shedding are useful for assessing associated traits such as pollen mass and floral opening duration [ 70 ].…”

Relationship of Quantitative Traits in Different Morphological Characters of Pea (Pisum Sativum L.)

“…El Hanafi et al [19] found that the maximum significant mid-parent heterosis in desirable direction was recorded for stem length trait. Hussein [20] confirmed the partial dominance for earliness and overdominance for the remainder growth trait stem length and number of branches.…”