Genetic Diversity of Ethiopian Tef (Eragrostis tef (Zucc.) Trotter) Varieties as Revealed by Morphological and Microsatellite Markers
| dc.contributor.advisor | Tesfaye, Kassahun (PhD) | |
| dc.contributor.author | Fikre, Tsion | |
| dc.date.accessioned | 2018-07-17T06:19:34Z | |
| dc.date.accessioned | 2023-11-08T16:39:09Z | |
| dc.date.available | 2018-07-17T06:19:34Z | |
| dc.date.available | 2023-11-08T16:39:09Z | |
| dc.date.issued | 2016-10 | |
| dc.description.abstract | Tef (Eragrostis tef (Zucc.) Trotter) is a gluten free cereal crop mainly grown in Ethiopia for food, feed and cash. This study was designed to assess the genetic diversity using morphological and molecular marker, and investigate trait association among tef varieties of Ethiopia. The experiment was conducted at two locations (viz. Debre Zeit and Alem Tena) for morphological study and National Agricultural Biotechnology Research Center, Holetta for molecular study in 2014/15 using 49 and 51 tef varieties based on 23 phenotypic traits and 9 microsatellites, respectively. In morphological study, combined analysis of variance over location revealed highly significant variation (P≤0.01) among the tested varieties for all recorded traits except for plant height and genotype x location interact significantly (P≤0.01) on 11 of the traits. The phenotypic coefficient of variation ranged from 3% for days to maturity to 30% for grain yield per plant, and the genotypic coefficient of variation ranged from 0% for second basal culm internode diameter to 21% for number of fertile tiller per plant. Estimates of broad sense heritability varied from 0% for second basal culm internode diameter to 95% for days to heading. The expected genetic advance as percent of the mean varied from 0% for second basal culm internode diameter to 32% for number of spikelets per main shoot panicle. The cluster analysis grouped the varieties into seven major groups consisting of one to 29 varieties. The first six principal components with eigenvalues greater than one explained 76% of the total variation. Grain yield showed significant positive correlation with panicle length, culm length, number of fertile tillers per plant, number of spikelets and primary branches per main shoot panicle, thousand seed weight, grain yield per plant and biomass yield. On the other set of experiment, the molecular study detected a total of 52 alleles with a mean of six alleles per locus ranged from five to seven. With a mean 0.69 the polymorphic information content (PIC) ranged from 0.59 for marker CNLTs27 to 0.77 for CNLTs86. The gene diversity ranged from 0.65 to 0.80 with a mean of 0.73. The degree of polymorphism among the groups varies from 67% for improved varities obtained from hybridization to 57% for wild relatives with the average of 63%. The lowest level of genetic differentiation and high level of gene flow were observed among the varieties obtained through hybridization and direct selection. Molecular analysis of variance higher percentage of variation within individuals (60%) and the variation among groups was the least (10%). Cluster analysis based on SSR data grouped the varieties into three major cluster groups. Principal Co-ordinate Analysis showed that the first three most informative principal coordinates accounted for 29% of the genetic variation. Generally, the present studies showed the existence of low genetic diversity among the released varieties which calls for timely action to widen the genetic diversity of Ethiopian released tef varieties. Moreover, both marker systems identified distinct varieties such Simada, Gola, Tsedey and Were Kiyu in the early maturing category that is suitable for terminal drought-prone area, and Etsub in late maturing category that is meant for optimum rainfall areas using both marker systems. The incorporation of these selected varieties and other divergent varieties as parent materials will strengthen the future tef breeding program through developing distinct varieties in the respective agro-ecologies. Key Words: Tef, Eragrostis tef, Genetic diversity, Morphological traits, Microsatellite markers, Trait Association. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/8848 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa Universty | en_US |
| dc.subject | Tef | en_US |
| dc.subject | Eragrostis tef | en_US |
| dc.subject | Genetic diversity | en_US |
| dc.subject | Morphological traits | en_US |
| dc.subject | Microsatellite markers | en_US |
| dc.subject | Trait Association | en_US |
| dc.title | Genetic Diversity of Ethiopian Tef (Eragrostis tef (Zucc.) Trotter) Varieties as Revealed by Morphological and Microsatellite Markers | en_US |
| dc.type | Thesis | en_US |