Grain yield variation and association of major traits in brown-seeded genotypes of tef [Eragrostis tef (Zucc.)Trotter]

Abstract

Background: Tef [Eragrostis tef (Zucc.) Trotter] is the major cereal crop of Ethiopia where it is annually cultivated on more than three million hectares of land by over six million small-scale farmers. It is broadly grouped into white and brown-seeded type depending on grain color, although some intermediate color grains also exist. Earlier breeding experiments focused on white-seeded tef, and a number of improved varieties were released to the farming community. Thirty-six brown-seeded tef genotypes were evaluated using a 6 × 6 simple lattice design at three locations in the central highlands of Ethiopia to assess the productivity, heritability, and association among major pheno-morphic traits.Results: The mean square due to genotypes, locations, and genotype by locations were significant (P < 0.01) for all traits studied. Genotypic and phenotypic coefficients of variations ranged from 2.5 to 20.3 % and from 4.3 to 21.7 %, respectively. Grain yield showed significant (P < 0.01) genotypic correlation with shoot biomass and harvest index, while it had highly significant (P < 0.01) phenotypic correlation with all the traits evaluated. Besides, association of lodging index with biomass and grain yield was negative and significant at phenotypic level while it was not significant at genotypic level. Cluster analysis grouped the 36 test genotypes into seven distinct classes. Furthermore, the first three principal components with eigenvalues greater than unity extracted 78.3 % of the total variation. Conclusion:The current study, generally, revealed the identification of genotypes with superior grain yield and other desirable traits for further evaluation and eventual release to the farming community.

Semi-dwarf tef lines for high seed yield and lodging tolerance in Central Ethiopia

“…The broad sense heritability estimates obtained in this study are commensurate with other earlier studies (Assefa et al 1999;Assefa et al, 2000). However, our results were also either slightly higher (Tilahun et al, 2012), or lower (Jifar et al 2015a;Jifar et al, 2015b) than earlier studies. These discrepancies could be due to the differences in the test genotypes and environments used.…”

“…This indicates that selection for such related traits can be made based on only those traits that can be assesses relatively easily. The positive and significant association detected among grain yield and that of shoot biomass and harvest index in this study is in line with the findings of several researchers (Chanyalew et al, 2006;Chanyalew et al, 2009;Jifar and Assefa, 2013;Jifar et al, 2015a;Jifar et al, 2015b). This indicates the relatively consistent association of the tef traits in various studies.…”

“…The range of variations estimated for both PCV (0.004 to 255.4%) and GCV (0.002 to173.9%) in the current work were greater than previous reports of 6.1 to 40.2% for PCV and 3.0 to 22.1% for GCV by Assefa et al (1999) or 2 to 58% for PCV and less than 1 to 35% for GCV by Assefa et al (2000). Besides, the value of the present finding is much higher than the estimated range of 4.3 to 21.7 for PCV and 4.0 to 20.3% for GCV by Jifar et al (2015a).…”

“…This indicates the relatively consistent association of the tef traits in various studies. Similarly, the positive and significant phenotypic association of lodging index with days to heading and maturity is in line with Jifar et al (2015b) but contrary to Jifar et al (2015a) with respect to the direction of association. These contrasting relationships between lodging index and days to heading was due to the differences in the type of tef varieties used in the two experiments.…”

“…Hence, further evaluation of the genotypes under the environment where they perform well will enable their recommendation for specific release. Previous works using various sets of tef genotypes, including germplasm accessions (Assefa et al, 1999), released varieties (Jifar et al, 2015a), and elite brown seed genotypes (Jifar et al, 2015b) indicated the existence of significant variability for diverse traits due to genotype, location, and genotype by location interaction effects on different traits. Besides, highly significant genotype by location interactions was also reported for days to heading, whole culm and second culm length, second culm internode diameter, peduncle length and harvest index (Assefa et al, 2000).…”