Morphological assessment of spikes in novel F4:5 breeding population hybrids of winter soft wheat (Triticum aestivum L.)

Winter wheat is a crucial cereal crop that significantly contributes to global food security. The study aimed to investigate the morphological characteristics of newly developed breeding population hybrids of winter soft wheat (F4:5), focusing on spike morphology and its implications for agronomic performance under rain-fed conditions. This research was conducted during the 2021-22 period at the Kaluga Agricultural Experimental Station in the Peremyshlsky District of the Kaluga Region. The breeding program evaluated spike traits in a diverse population, selecting 6,999 spikes from 2,060 genotypes (≥2.85 g). Seeds were sown at 500 seeds/m² in a 10 × 50 m plot. Traits were analyzed using IBM SPSS v23x64 with ANOVA and Pearson correlation. This study examined spike morphological traits in winter soft wheat, revealing strong correlations critical for breeding. Spike weight correlated highly with grain weight (r=0.97), grain number (r=0.63), and grain weight with grain number (r=0.68). Spike length positively influenced mean grain weight, increasing from 2.44 g at 7.00 cm to 3.01 g at 13.50 cm, though variability was notable (CV=16.88% at 12.00 cm). Spikelet number also correlated with mean grain weight, rising from 2.43 g at 12 spikelets to 3.10 g at 22, but with greater variability (CV=18.00%). An inverse relationship was observed between spike length and spikelet density, decreasing from 23.24 to 14.82 as length increased from 7.00 cm to 13.50 cm. These results highlight the need to balance spike traits for optimal yield and adaptability. © 2025 Elsevier B.V., All rights reserved.