African Journal of Plant Breeding

African Journal of Plant Breeding ISSN: 2375-074X Vol. 4 (1), pp. 172-182, January, 2017. © International Scholars Journals

Full Length Research Paper

A study of genetic variation and grain quality traits in bread wheat (Tritium aestivum L.) genotypes

James Ganno1*, Dawit Alemu2 and Gidada Ayalew3

1Plant Breeding Department, Axum Agricultural Research Center, Axum, Ethiopia.

2Department of Plant Breeding and Genetics, Haramaya University, Dire Dawa, Ethiopia.

3Department of Plant Breeding and Genetics, Mekelle University, Mek'ele, Ethiopia.

*Corresponding author. E-mail: james_ganno@gmail.com.

Accepted 22 January, 2017

Abstract

Forty-nine bread wheat genotypes were tested at Axum, Northern Ethiopia in 2016/17, with the objective of assessing the extent of genetic variation, correlation and path analysis of wheat genotypes in yield and grain quality traits using 7 x 7 triple lattice design. Data were collected for 17 agronomic and grain quality characters. For each of the test entries, samples of 500 g grains were taken from each plot for quality analysis. The NIR spectrophotometer (NIR Infratec 1241 Grain analyzer, Sweden) was used to analyze wheat samples for their protein, wet gluten, zeleny sedimentation volume and starch content based on dry weight basis. Data were subjected to analysis of variance which revealed significant differences among the genotypes for all the characters. The genotypic coefficient of variation (GCV) ranged from 1.63 (for starch content) to13.30% (for grain yield). The broad sense heritability (H2) ranged from 15.89 (for number of tillers) to 97.16% (for days to heading), while genetic advance as percent of mean (GAM) from 2.01 (for starch content) to 19.63% (for days to heading). The GCV and phenotypic coefficient of variation (PCV) differences were low in magnitude for days to heading and days to maturity, and H2 values were coupled with moderate to high GAM. This suggests selection based on phenotype of genotypes could be effective to improve these characters. Grain yield was positively and significantly correlated with biological yield (0.72), harvest index (0.65), plant height (0.51), thousand kernel weight (0.31), hectoliter weight (0.37) and starch content (0.32), of which biomass yield (0.85) and harvest index (0.70) had the highest positive direct effect on grain yield. Thus, selection for higher mean values of biomass yield and harvest index could be considered simultaneously for selection of higher grain yield.

Key words: Bread wheat, correlation, genetic coefficient of variation, genetic advance, grain quality, heritability.