Genetic Analysis of Grain Yield and Stem Rust Resistance in Bread Wheat Using Six-Population Model

Nagy, Abd El-Fattah Mohammed; Ibrahim, Shaimaa E.; Mohamed, Mona E.

doi:10.21608/jpp.2025.422993.1507

Genetic Analysis of Grain Yield and Stem Rust Resistance in Bread Wheat Using Six-Population Model

Document Type : Original Article

Authors

¹ Agriculture research center, Field crops research institute, wheat research department

² Wheat Research Department, Field Crops Research Institute, ARC, Egypt.

³ Wheat Diseases Research Department, Plant Pathology Research Institute, ARC, Egypt.

10.21608/jpp.2025.422993.1507

Abstract

This study was conducted at El-Gemmeiza Agricultural Research Station, Egypt, during 2022/23, 2023/24, and 2024/25 wheat growing seasons to investigate the genetic behavior of yield traits and stem rust resistance in bread wheat (Triticum aestivum L.). Six populations (P₁, P₂, F₁, F₂, BC₁, and BC₂) derived from three crosses (Line1 × Line2, Line1 × Misr2, and Line2 × Misr2) were evaluated using RCBD in three replications. Mean performance indicated that F₂ populations were generally intermediate and tended to be lower than F₁ means for several traits, particularly no. of spikes/plant and grain yield/plant. Significant positive heterobeltiosis was observed for no. of spikes/plant, no. of grains /spike, 100-grains weight, and grain yield/plant across the three crosses. Genetic analysis revealed that additive × additive and additive × dominance interactions were more important than dominance × dominance effects, while epistatic effects played a comparable role to additive and dominance gene actions. Concerning stem rust, Cross I (Line1 × Line2) showed complete resistance, while Misr2 was susceptible and the F₁ generations of Crosses II and III were moderate response to stem rust. Segregating generations (F₂, BC₁, and BC₂) displayed variable responses. Chi-square analyses confirmed that resistance in Crosses I and II followed a single dominant gene model (3R:1S), while Cross III fitted a complementary gene model (9R:7S). Overall, results highlight the significance of additive and epistatic effects in governing yield traits and demonstrate different modes of genetic controlling stem rust resistance. These findings provide useful implications for improving productivity and stem rust resistance.

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