Agro-Morphological and Molecular Characterization of Enset (Ensete Ventricosum (Welw.) Cheesman) Landraces from Ethiopia
| dc.contributor.advisor | Tesfaye, Kassahun (PhD) | |
| dc.contributor.author | Yemataw, Zerihun | |
| dc.date.accessioned | 2019-07-29T09:21:12Z | |
| dc.date.accessioned | 2023-11-08T16:33:42Z | |
| dc.date.available | 2019-07-29T09:21:12Z | |
| dc.date.available | 2023-11-08T16:33:42Z | |
| dc.date.issued | 2018-06-01 | |
| dc.description.abstract | The study was conducted with the objective of assessing and documenting indigenous knowledge and perception associated with the distribution, diversity, Enset Xanthomonas Wil, its etiology and mode of transmission, and management of enset in the country, and the genetic diversity of enset landraces that were obtained from different geograpHical locations in Ethiopia, using Phenotypic traits and to develop a genome sequence data, identify and develop single nucleotide polymorpHism (SNPs) and genotyping of landraces that serve as molecular markers for future marker assisted breeding. Enset genetic resource utilization and management study was conducted in eight ethnic groups in the Southern Nations, Nationalities and Peoples’ Regional State. The data was collected mainly through individual interviews and direct on-farm participatory monitoring and observation, key informant interviews. Relevant secondary data, literature and inter-personal data were collected from unpublished progress report from National Enset Research Project, elderly people and senior experts. Enset-based farming system is one of major agricultural systems in Ethiopia that serves as a backbone for at least one-forth of country’s population. Farmers used three morphological characters, two growth attributes, disease resistance and five use values traits in folk classification and characterization of enset. A total of 312 folk landraces have been identified. The number of landraces cultivated on individual farms ranged from one to twenty eight (mean of 8.08 ± 0.93). All ethnic groups in the study area use five use categories in order of importance: kocho yield and quality, bulla quality, amicho use, fiber quality and medicinal/ritual value. Of the 312 landraces 245 landraces having more than two use types. Management and maintenance of on-farm enset diversity is influenced by systematic propagation of the landraces, exchange of planting material and selective pressure. Farmers’ knowledge and perception of enset Xanthomonas wilt showed that a significant number of farmers are aware of EXW, its symptoms, etiology and transmission and spread, but they are not able to readily relate modes of spread to control methods. Since 2002, EXW became prominent in Hadiya, with the highest EXW incidence and severity, followed by Wolaita, and Kembata-Tembaro. Farmers identified EXW as the major cause for declining production and productivity of enset in the region. EXW has spread widely and rapidly in southern Ethiopia, with significant socioeconomic impacts in smallholders’ livelihoods. There is a need for developing knowledge-based strategies and awareness-raising campaign for EXW management. In general, the existing farmers’ knowledge on naming, classification and diversity should be complemented with maintenance of the creative dynamics of traditional knowledge and transmission of the knowledge are crucial for constructing sustainable management. Assessment of genetic diversity in enset using Phenotypic markers were subjected to ANOVA and the variations among the landraces and regions were significant (p ≤ 0.01) for all the 15 traits studied. Mean for plant height, central shoot weight before grating, and fermented squeezed kocho yield per hectare per year showed regional variation along an altitude gradient and xxiii across cultural differences related to the origin of the collection. Furthermore, there were significant correlations among most of the characters. This included the correlation among agronomic characteristics of primary interest in enset breeding such as plant height, pseudostem height, and fermented squeezed kocho yield per hectare per year. Altitude of the collection sites also significantly impacted the various characteristics studied. Cluster analysis grouped the landraces into five distinct groups, with two outlying landraces. Landraces originating from regions with similar agro-climatic conditions grouped together. Principal component analysis showed that the first four principal components accounted for ~74% of the total variance of the 387 enset landraces for the 15 quantitative traits studied. The linear discriminant analyses depicted about 40.8% (160 of the 387) and 45.2% (175 of 387) correct origin-based classification of the germplasm in terms of altitude zones and regions, respectively. Six qualitative morphological traits were also analyzed using the Shannon Weaver diversity index (H’).The Shannon-Weaver Diversity Index (H') for all sampled germplasm ranged from 0.50 to 0.89, with a mean of 0.73. Analysis of variance for H' revealed highly significant (p<0.01) differences among regions for all traits. Cluster analysis grouped the landraces into four clusters. A high proportion of landraces sourced from similar altitude classes and similar regions were grouped together. This indicated that there was wide variability among landraces studied. The Phenotypic differences in these 15 traits suggest significant degrees of genetic variation and that these traits can be exploited to identify potential donors for future enset improvement efforts. The implication of the current results for plant breeding, germplasm collection, and in situ and ex situ genetic resource conservation are discussed. Seventeen (for genome sequence analysis) and four hundred eighty (for SNP catalogue development) different enset landraces used were obtained from Areka Agricultural Research Center field germplasm. We present raw sequence reads and genome assemblies resulting from the sequencing of 17 landraces of the crop plant enset. Landraces having the same names but different origin showed different reads. For SNP detection, we considered only sites either homozygous or heterozygous for all 17 data sets. We were able to identify 33,200 singlenucleotide variant sites. We generated a series of phylogenetic trees and there was no sequence variation at this locus among the 17 genomes presented here. By examining the pattern of bands in agarose electrophoresis of the product after restriction digestion, it is possible to assess the genotype at that SNP location. We applied the 22 PCR-RFLP assays to single accession of E.ventricosum. Further, we then went on to apply 5 of these assays to several hundred E. ventricosum landraces. This findings will facilitate high-resolution studies to determine the genetic architecture of traits of economic and ecological importance, to study the structure of enset populations and to apply genomic selection in breeding programs. In general, farmers cognitive, morphological, sequence and SNP output clearly distinguished between all landraces, even though they were genetically similar. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/18685 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Enset | en_US |
| dc.subject | Ethiopia | en_US |
| dc.subject | Farmer’s Knowledge | en_US |
| dc.subject | in Situ and Ex Situ Conservation | en_US |
| dc.subject | Landraces | en_US |
| dc.subject | on-Farm Diversity and Management | en_US |
| dc.subject | Phenotypic Variation | en_US |
| dc.subject | Southern Ethiopia | en_US |
| dc.subject | Snp | en_US |
| dc.subject | Xanthomonas Wilt | en_US |
| dc.title | Agro-Morphological and Molecular Characterization of Enset (Ensete Ventricosum (Welw.) Cheesman) Landraces from Ethiopia | en_US |
| dc.type | Thesis | en_US |