Variability and Trait Association in Recombinant Inbred Lines of Eragrostis tef x E. Pilosa

Demeke, Mewa Bayable (2008) Variability and Trait Association in Recombinant Inbred Lines of Eragrostis tef x E. Pilosa. Masters thesis, Addis Ababa University.

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Abstract

A study was conducted to assess variability and trait association in recombinant inbred lines (RILs) of Eragrostis tef x E. pilosa crosses. A total of 81 lines were planted using RCB design with three replications at Debre Zeit and Akaki in 2007 main rainy season. The result indicated that there exists difference among the lines for most of the traits included in this study. High difference was also obtained for almost all the traits between the two environments such that more attention was given to single site analysis. Grain yield showed the maximum PCV (> 40%) and GCV (> 30%) followed by spikelet per panicle (PCV > 25%, GCV > 20%). High PCV (> 20%) and moderate GCV (> 15%) was recorded for lodging index. Moderate GCV (> 10%) was also recorded for plant height, panicle length, culm diameter and strength, and shoot biomass, but GCV was low for shoot biomass and 100-seed weight at Akaki. Most of the traits showed high heritability (not < 40%) except first culm strength and tiller. Genetic advance as % of mean was maximum for grain yield (> 50%) followed by spikelet per panicle (> 30%). For this parameter, panicle length, lodging index and plant height also revealed high values (> 20%), but large difference was recorded between the sites for shoot biomass and 100-seed weight; > 25% at Debre Zeit but < 10% at Akaki. Moderate genetic gain (> 10%) was recorded for length of growing period and culm characters. Genetic variability and potential of genetic gain for number of tillers was consistently very low. Most of the traits were found associated. Correlation study showed strong positive association of lodging index with most other traits except with culm diameter and spikelet per panicle at Debre Zeit. However, path analysis revealed that effect of some of the traits on lodging was weak mainly at Akaki and only culm strength at the second internode showed consistently strong positive effect. Plant height, days to maturity and spikelet per panicle showed strong negative effect and panicle length strong positive at Debre Zeit. Effect of most traits on grain yield was high-positive; only days to maturity showed consistently low effect. Principal component analysis showed that about 45% of the gross variance among lines laid in PC1 and explained largely by traits like plant height, panicle length, days to maturity and days to heading. Generally, the study indicated that there exists considerably high genotypic variability, up to transgression beyond the better parent, for economically valuable traits including lodging index, which verified the importance of E. pilosa in diversifying the tef germplasm base. The complex associations implied the need to consider many traits in improving those traits as grain yield and its limiting factor, lodging. The high variability between the sites indicated the need to work with much more environments to represent most tef growing conditions.

Item Type: Thesis (Masters)
Uncontrolled Keywords: RIL, Variability, Association, E. tef, E. pilosa
Subjects: Q Science > Q Science (General)
Q Science > QH Natural history > QH301 Biology
Q Science > QH Natural history > QH426 Genetics
Q Science > QK Botany
Divisions: Africana
Depositing User: Selom Ghislain
Date Deposited: 01 Oct 2018 11:50
Last Modified: 01 Oct 2018 11:50
URI: http://thesisbank.jhia.ac.ke/id/eprint/5836

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