Combining ability and gene action controlling yield and yield components in bread wheat (Triticum aestivum L.) under drought‐stressed and nonstressed conditions

Abstract

This study determined the combining ability and gene action controlling yield and yield‐related traits in wheat under drought‐stressed and nonstressed conditions. Twelve parents possessing Rht‐B1b and Rht‐D1a genes and their 66 half‐diallel crosses were evaluated under field and glasshouse conditions. Plant height (PH), productive tiller number (TN), kernels per spike (KPS), thousand seed weight (TSW) and grain yield (GY) were recorded. Analysis of variance, heritability, correlation and combining ability analyses were performed. Heritability estimates ranged from 53.00% (TN) to 63.07% (KPS). Yield showed positive correlations with all other traits under all test conditions. Significant GCA effects were observed for all traits recorded across test conditions, except for yield in the glasshouse. All Baker's ratios were less than a unit, indicating predominance of nonadditive gene action. Consistently high positive GCA effects were observed on LM02 for GY; LM02 and LM23 for KPS; and LM04 and LM09 for TSW, while LM17 and LM21 had negative effects for PH. Good general and specific combiners will be used for further breeding and selection.

Green revolution ‘stumbles’ in a dry environment: Dwarf wheat with Rht genes fails to produce higher grain yield than taller plants under drought

“…Similarly, most South African hybrid lines with short stature had a lower yield in greenhouse experiments and in field trials under dry conditions. Here the authors concluded that the ideal stature for wheat should be optimized to an intermediate plant height (Mwadzingeni, Shimelis, & Tsilo, 2018).…”

“…Therefore, the proposed ideotype of wheat stature may be precisely tuned and optimized to a moderately reduced plant height, as suggested earlier (Mwadzingeni et al, 2018;Richards, 1992a) but with improved drought tolerance.…”

Pattern of Genetic Inheritance of Grain Zinc and Iron Content, Agronomic and Biochemical Traits in Bread Wheat Using Mixed Linear Models Under Salinity Stress

“…The differences between those results and our study may be due to differences in the level of salt stress, different genetic backgrounds, and/or screening environment used. Concerning thousand seed weight and grain yield, Mwadzingeni et al (2018) observed significant effects for GCA under normal and drought-stress conditions indicated the influence of additive gene action.…”

Evaluation and stability analysis of some bread wheat genotypes under heat stress

“…Some genotypes showed great heat tolerance and gave the highest grain yield per plant under both sowing dates was observed Khajuria et al (2016) and Ali et al (2020). Heritability estimates were moderate for grain yield (Sharma et al (2010), Ahmad et al, 2017 andMwadzingeni et al, 2018). High heritability in broad sense estimates for days to heading (Singh et al, 2013 andElbasier et al, 2019).…”