Combining ability and gene action for grain yield and its chemical composition under normal condition and heavy metal stress in bread wheat [electronic resource].

Includes references.

Five diverse bread wheat genotypes (Sids 13, Giza 168, Gemmeiza 11, Line 1 and Line 2) were crossed in a half- diallel model in 2012/2013 season at the Experimental Farm, Faculty of Agriculture, Zagazig University, Egypt. The five parents and their ten Fl hybrids were evaluated for grain yield, its components and the chemical composition of grains under normal condition and heavy metals (Zn, Pb and Cd) stress in two adjacent experiments during 2013/2014 season. Each experiment was designed in a randomized complete block design with three replicates. Heavy metals stress reduced number of productive tillers/plant (1 %), number of grains/spike (11.7%), 1000- grain weight (g) (11.6%) and grain yield I plant by (23%), while increased the grain content of each protein (1 %), proline (13%), Zn (33%), Pb (51.7%) and Cd (32%) compared to the normal condition. Significant differences among parental wheat genotypes and their F 1 crosses for grain yield/ plant, its components and chemical composition of wheat grains were recorded. Sids 13 proved to be better general combiner for grain yield /plant ,while LI was good general combiner for grain yield/plant, protein and proline contents in wheat grains under both normal and stress environments. Both additive and dominance gene action were involved in the inheritance of wheat grain yield /plant, its components and the chemical composition of wheat grains with the prevailed type of dominance under both environments . Narrow sense heritability was high for proline content (67.73%), Cd content (61.05%) under stress condition and number of productive tillers/plant (50.31%) under the normal condition: moderate for grain yield /plant (47.25% and 32.06%), protein content (31.75% and 47.05%) under both environments, number of grains /spike (33.34 %) and Pb content (32.34%) under stress, the contents of proline (45.99%) and Zn (34.9%) under the normal condition. Whereas it was low for number of productive tillers /plant (26.91 %), Zn content (24.7%) under stress, number of grains/spike (21.77%), Pb content (29.22%) and Cd content (21.66%) under the normal condition as well as 1000-grain weight (20.1% and 27.4%) under both environments, with the same respect.

Summary in Arabic.

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