Genetic components and combining ability for grain yield and yield components using line × tester analysis in bread wheat (triticum aestivum l. )‎

الملخص EN

Eight bread wheat (Triticum aestivum L.

) genotypes included 6 lines and 2 testers were crossed in a line × tester mating design.

The 12 F₁'s and their parents were evaluated for grain yield/plant and 9 agronomical traits.

The results indicated highly significant genetic variability for all studied traits.

Line Q8 was the best combiner for early flowering date, grains/spike, grain weight/spike and 1000-kernel weight traits.

While line Q10 was the best parent for tallness and grain yield/plant.

The T1 (PI330456) was a potential tester parent for spike length, spikelets/spike, stem diameter, grains/spike, and grain yield/plant.

While T2 (PI330458) was good combiner for earliness and 1000-kernel weight.

Several hybrids showed highly significant positive specific combining ability (SCA) for some studied traits.

Mother lines played a positive influential role towards plant height, spike length, tillers/plant and grain weight/spike.

While paternal testers influence was predominant for days to flowering, spikelets/spike, stem diameter, grains/spike, 1000-kernel weight and grain yield/plant.

Additive gene action was found for plant height, spikelets/spike, stem diameter grains/spike and grain weight/spike.

While, for days to flowering, spike length, tillers/plant, 1000-kernel weight and grain yield/plant, non-additive gene action was predominant.

High estimates of broad- and narrow-sense heritability for grains/spike, grain weight/spike, plant height and 1000-grain weight.

Maximum genetic advance along with high narrow-sense heritability were observed for grains/spike and plant height reflecting that a reliable selection for these traits can be made on the basis of phenotypic performance in early generations.

Highly significant positive correlations were observed between most studied traits.

Additive gene action was found for plant height, spikelets/spike, stem diameter grains/spike and grain weight/spike.

While, for days to flowering, spike length, tillers/plant, 1000-kernel weight and grain yield/plant non-additive gene action was predominant.

High estimates of broad- and narrow-sense heritability for grains/spike, grain weight/spike, plant height and 1000-grain weight.

Maximum genetic advance along with high narrow-sense heritability were observed for grains/spike and plant height reflecting that a reliable selection for these traits can be made on the basis of phenotypic performance in early generations.

Highly significant positive correlations were observed between most studied traits.