Genetic parameters for some yield and yield components characters in four crosses of bread wheat under two water regime treatments [electronic resource].

Includes references.

Six populations; P₁, P₂, F₁, F₂, BC₁ and BC₂ of four bread wheat crosses were used in this study to determine quantitative genetic parameters for yield and its components characters under normal and water stress treatments. The means of the six generations were recorded for plant height, spikes number plant⁻¹, grains number spike⁻¹, 100-grain weight and grain yield plant⁻¹ in four crosses namely; Line 1 × Sakha 93, Line 1×Sakha 94, Sakha 93×Gemmiza 9 and Sakha 94 × Gemmiza 9 generated from four diverse parents. The experiment was carried out in 2006/2007 to 2008/2009 seasons at Sakha Agric. Res. Station, ARC. The means of the four crosses significantly decreased under the water stress treatments for yield and its components characters as the effect of water stress at most cases. The T-test of differences between parents of each cross under each treatment showed highly significant values in most cases in the four studied crosses under both treatments. The results showed the importance of additive gene effects in the inheritance of plant height and spikes number plant⁻¹, while, additive, dominance and epistasis were the important in the inheritance of grains number spike⁻¹, 100-grain weight and grain yield plant⁻¹ at most cases under both normal and water stress treatments. Moreover, additive genetic variance played the greatest and the important role in the inheritance of plant height, spikes number plant-1 and grain yield plant⁻¹ at most cases under both water treatments. On the other hand, dominance genetic variance was the greatest and the important in the inheritance of grains number spike-1 and 100-grain weight at most cases under both water treatments. On the other side, heritability in broad sense had medium to high percentages for all studied characters at all cases under normal and water stress treatments. Meanwhile, heritability in narrow sense had moderate to high values for yield and yield components characters at most cases under both water treatments, except grains number spike⁻¹ which had low values at most cases under both water treatments. Genetic advance under selection was low for plant height at most cases under both water treatments. While, it was high for spikes number plant⁻¹ and grain yield plant⁻¹ at most cases under both water treatments. Also, it was founded to be low to high for plant height, grains number spike⁻¹ and 100-grain weight at most cases under both water treatments.

Summary in Arabic.

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