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Accueil du site → Doctorat → Ethiopie → Analyses of Phenotypic and Molecular Diversity, Genotype by Environment Interaction and Food-Feed Traits in Tef [Eragrostistef (Zucc.) Trotter]

Addis Ababa University (2018)

Analyses of Phenotypic and Molecular Diversity, Genotype by Environment Interaction and Food-Feed Traits in Tef [Eragrostistef (Zucc.) Trotter]

Jifar, Habte

Titre : Analyses of Phenotypic and Molecular Diversity, Genotype by Environment Interaction and Food-Feed Traits in Tef [Eragrostistef (Zucc.) Trotter]

Auteur : Jifar, Habte

Université de soutenance : Addis Ababa University

Grade : Doctor of Philosophy in Biology (Applied Genetics) 2018

Résumé partiel
Tef [Eragrostis tef (Zucc.) Trotter] is an indigenous major cereal crop widely grown and utilized in Ethiopia. It is an excellent source of healthy and nutritious human food and livestock feed. However, its productivity is significantly lower than that of major cereals grown in Ethiopia. Although diverse constraints contribute for its inferior grain yield, the huge diversity present in tef germplasm has not been exploited. This study was, therefore, conducted to assess the phenotypic and molecular diversity, genotype by environment interactions and variation of food-feed traits in tef genotypes from various sources. The field experiments were conducted at Holetta, Debre Zeit, Alem Tena, Adet, Axum and Shambu using randomized complete block design with three replications whereas, the laboratory analyses were conducted at the University of Bern in Switzerland, Sci-Co in South Africa, International Livestock Research Institute (ILRI) in Ethiopia and International Crops Research Institute for Semi-Arid Tropics (ICRISAT) in India. Phenotypic diversity was assessed based on 12 quantitative and five qualitative traits of 188 tef genotypes while, the genotyping study was conducted using 189 genotypes with 16 SSR markers. Results from phenotypic study revealed the existence of huge variability in plant height (60.7 to 107.1 cm), panicle length (19.5 to 39.5 cm), number of fertile tillers per plant (2.1 to 5.5), number of spikelets per panicle (156.7 to 441.7), thousand kernel weight (20.7 to 33.0 mg), grain yield (3.7 to 7.3 t/ha) and lodging index (44.7 to 79.3%). Molecular diversity study generated a total of 260 alleles for the total studied loci. Cluster and STRUCTURE analyses showed four gene pools, but with high level of admixtures due xix to geographic proximity and/or trans human seed exchange. Analysis of molecular variance showed significant variation of 56.6% within individuals, 40.8% among individuals within population and 2.6% among populations. Based on SSR study, furthermore, a core collection composed of 64 genotypes (33.9%) is suffice to capture the entire alleles of studied genotypes. Significant variations were also detected for all traits due to genotypes, environments and their interaction.

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