Evaluation of pollination traits important for hybrid wheat development in Great Plains germplasm

Abstract

Hybrid wheat (Triticum aestivum L.) offers potential yield advantages over conventional inbred cultivars. For hybrid wheat to be a commercial success, the cost to produce the hybrid seed needs to be minimized. Although wheat is naturally self‐pollinated, hybrid wheat seed production can be improved by increasing the amount and availability of pollen for cross‐pollination. This research examined 19 pollination traits using the Hard Winter Wheat Association Mapping Panel for 3 years. Anther extrusion, pollen 50 date (date at which a genotype has 50% of spikes pollinating), plant height, and pollination duration (last spike pollen 50 date minus first spike pollen 50 date) were identified as the most important traits for hybrid seed production. Anther extrusion, plant height, and pollen 50 date varied widely among genotypes, while pollination duration had significant genotypic differences in one year of testing. These traits also had significant genotype × year interactions, but better and poorer performers were consistent among years. Anther extrusion was weakly, negatively correlated with plant height, and high anther extrusion semi‐dwarf genotypes were identified. Pollination duration was reduced in a high temperature (>30°C) environment, and genotypic differences in pollination duration were identified only in a milder temperature (24°C) environment. Hierarchical clustering suggested that excellent pollinator genotypes with high anther extrusion and longer pollination duration tended to pollinate early and were of short to moderate stature. Pollination traits were higher when temperatures were mild, which benefited early genotypes because they pollinated before higher temperatures limited their pollination duration.

Green Revolution dwarfing Rht genes negatively affected wheat floral traits related to cross‐pollination efficiency

“…(2002) suggested that well‐spaced spikes carrying large lodicules, a soft lemma, and palea would facilitate the wide opening of each floret. Environmental and genotypic variability here reported for male floral traits under field conditions were partially documented for AE (Boeven et al., 2016; Garst et al., 2023; Langer et al., 2014; Muqaddasi et al., 2016; Muqaddasi, Brassac, et al., 2017; Muqaddasi, Pillen, et al., 2017; Sade et al., 2022), AL (Komaki & Tsunewaki, 1981; Nguyen et al., 2015; Song et al., 2018), and AFL (Beri & Anand, 1971; Denisow et al., 2022). Our results showed that the degree of dwarfism produced by the different combinations of Rht genes resulted in significant reductions in parameters of strategic importance for the development of elite pollinators needed for hybrid wheat breeding programs.…”

“…The degree of this response was genotype and environment‐dependent. The effect of the different dwarfing alleles reducing AE was clearer under high‐yield potential environments like those explored under German conditions (Figures S1b and S2b) due to longer photoperiod and optimal temperatures that increase pollination duration compared to Argentinian conditions (Garst et al., 2023; Jones et al., 2017).…”

“…Hybrid wheat breeding is a promising strategy to increase grain yield and stability. With yield improvements ranging from 10 to 25% as well as enhanced resistance against biotic and abiotic stresses, the development of new hybrids is gaining attention among breeding programs worldwide (Boeven et al, 2016;Garst et al, 2023;Longin et al, 2012Longin et al, , 2013Matuschke et al, 2007;Okada & Whitford, 2019;Sade et al, 2022). In the face of quickly declining arable land expansion and increases in the incidence of abiotic/biotic stresses within climate change, a next wave of increase in potential yield and global production of wheat is needed (Gornicki & Faris, 2014).…”