Combining ability of bread wheat (Triticum aestivum L.) genotypes for yield and related traits with silicon fertilization

Silicon (Si), a chemical element, enhances sustainable wheat productivity by improving plant turgidity, nutrient uptake, enhancing beneficial microbial effects and improving yield under drought conditions. Limited studies with Si fertilization explored the gene action and inheritance patterns of yield and yield-related traits in wheat. The objective of this study was to assess the genetic determinants of yield and yield components in newly developed wheat populations under Si fertilization to guide breeding and select desirable parents and progenies for variety development. Seven wheat parents were selected based on yield and drought tolerance and were crossed using a full diallel mating design. Forty-two full-sibs were generated and evaluated along the parents under controlled environment conditions, without and with granular Si application (3g/pot) for precision phenotyping and selection. The analysis of variance (ANOVA) showed significant genotype (G) by Si treatment (T) interaction ( p < 0.05) affecting the number of kernels per spike (KPS), aboveground biomass (AGB) and grain yield (GY). Maternal effects were significant for plant height (PH), productive spike number (PS) and kernels per spike (KPS) with Si application. Si application significantly ( p < 0.05) improved the general combining ability (GCA) effects for PH, PS, spikelets per spike (SPS), KPS; hundred seed weight (HSW), harvest index (HI) and GY. The specific combining ability (SCA) effects were significant ( p < 0.05) for PH, PS, KPS, HSW and GY with Si application. With Si application, positive and significant SCA effects were recorded for GY for direct crosses MC4 x MC8 (1.57) and MC6 x MC10 (2.68). The GCA/SCA ratio was relatively higher (0.77) for KPS, with Si application indicating the preponderance of additive genes. Overall, the Si application complemented the additive gene effect on yield and yield-related traits in both direct and reciprocal crosses. Further research is required to examine the accumulation of maximum favourable additive genes in advanced generations of wheat through field evaluations of the breeding populations under Si application.