Estimation of gene action for yield traits under water stress conditions in wheat

Water deficit, is one of the major constraints that affects every aspect of the plant growth and development, consequently yield productivity. Breeding for drought tolerance requires the knowledge of gene action governing different yield traits. Six wheat genotypes were crossed in 6x6 half diallel....

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Published in:Sarhad journal of agriculture 2012-12, Vol.28 (4), p.551-558
Main Authors: Jatoi, W.A. (Sindh Agriculture Univ., Tandojam (Pakistan). Dept. of Plant Breeding and Genetics), Baloch, M.J. (Sindh Agriculture Univ., Tandojam (Pakistan). Dept. of Plant Breeding and Genetics), Kumbhar, M.B. (Sindh Agriculture Univ., Tandojam (Pakistan). Dept. of Plant Breeding and Genetics), Keerio, M.I. (Sindh Agriculture Univ., Tandojam (Pakistan). Dept. of Crop Physiology)
Format: Article
Language:English
Subjects:
COMBINING ABILITY
CROP YIELD
Crop yields
DIALLEL ANALYSIS
DROUGHT RESISTANCE
DROUGHT STRESS
F1 HYBRIDS
Gene expression
GENE INTERACTION
Genetic aspects
GENETIC VARIATION
GENOTYPES
HARVEST INDEX
HEIGHT
HYBRIDIZATION
Physiological aspects
Plant genetics
Quantitative genetics
SPIKELETS
SPIKES
TILLERING
TRITICUM AESTIVUM
Wheat
YIELD COMPONENTS
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Summary:Water deficit, is one of the major constraints that affects every aspect of the plant growth and development, consequently yield productivity. Breeding for drought tolerance requires the knowledge of gene action governing different yield traits. Six wheat genotypes were crossed in 6x6 half diallel. The parents and 15 F1 hybrids were evaluated in a randomized complete block design with four replications under normal and stress Latif Farm, Sindh Agriculture University, Tandojam during 2010. The analysis of variance revealed significant effect of yield traits which allowed determining the type of gene action controlling such traits. The mean squares for general combining ability GCA) and specific combining ability (SCA) were significant for all the traits in both environments. However, GCA and SCA variances were greater for grains per spike, grain yield per plant and seed index under drought conditions indicating the importance of additive and non-additive genes advocating these traits. In both non-stress and in water stress treatments, the degree of dominance was above unity (greater than 1.0) for productive tillers per plant, spike length, spikelets per spike, grains per spike, grain yield per plant and seed index which indicated over dominant type of gene action whereas only plant height exhibited less than unit degree of dominance in non-stress conditions suggested partial to near dominant genes for this trait. Similarly, the regression line intercepted the wr-axis below the origin for all the characters in both non-stress and stress at anthesis except plant height (non-stress) re-confirmed that all the studied characters were controlled by over dominant type of gene action, nonetheless for plant height in non-stress, the regression line had cut the wr-axis exactly at the origin signifying dominant type of gene action. The display of array points on the regression line from origin, by and large, indicated that parents TD-1 and TJ-83 being far away possessed more recessive genes under both the environmental conditions for productive tillers per plant, spikelets per spike, grains per spike and grain yield per plant whereas parents Sarsabz and Moomal being nearer to the origin retained more dominant genes for plant height and productive tillers per plant (in stress) SKD-1 for spike length (in stress Kiran and SKD-1 for spikelets per spike and grains per spike (non-stress) and Kiran and Sarsabz for grain yield per plant and seed index in non-stress and stress
ISSN:1016-4383