Isolation and Characterization of Endophytic Trichoderma Isolates for Antagonistic Activity Against Coffee Wilt Disease (Gibberella Xylarioides) in Keffa Zone, Southwestern Ethiopia
| dc.contributor.advisor | Alemu, Tesfaye (PhD) | |
| dc.contributor.author | Berihun, Beyene | |
| dc.date.accessioned | 2019-09-06T06:49:39Z | |
| dc.date.accessioned | 2023-11-09T04:20:49Z | |
| dc.date.available | 2019-09-06T06:49:39Z | |
| dc.date.available | 2023-11-09T04:20:49Z | |
| dc.date.issued | 2018-09-04 | |
| dc.description.abstract | The present study aimed to evaluate, test and characterize potential biocontrol of endophytic Trichoderma isolates against coffee wilt pathogen (Gibberella xylarioides). In this study we examined the effect of pH and temperature on the mycelia growth and spore yield of Trichoderma isolates in batch culture. Coffee root samples were collected from different ecological habitat of Kaffa zone for the isolation of endophytic Trichoderma isolates. The ability of Trichoderma isolates to grow at pH 4.5, 6.5 and 7.5 were tested in liquid potato dextrose broth (PDB) medium. The effect of volatile and non-volatile compounds produced by Trichoderma isolates on radial growth of pathogenic fungi, F. xylarioides was also determined. In vitro antagonistic bioassays were performed to evaluate and determine the potentiality of Trichoderma isolates as biocontrol agents against F. xylarioides. The pH and temperature had significant effect on the growth and sporulation of Trichoderma isolates. It was observed that the optimum pH for maximum mycelial growth and spore yield produced by Trichoderma isolates in batch cultures was pH 7.5 while the optimum temperature for mycelial growth and the maximum spore yield was produced at optimum temperature was 25OC. This work has revealed the important role that environmental conditions plays in the mycelia growth and spore yield of Trichoderma isolates, a biocontrol agent. In in-vitro bioassay the experimental results showed that all isolates of Trichoderma were able to inhibit the growth of F. xylarioides under in vitro experiment at rates ranging from 42.2 % to 69 % after 10 days of incubation. The highest mean inhibitory effect on the growth of the test pathogen was achieved by Gimbo Trichoderma isolate 05 (Gim-T05) (69%) followed by Gim-T10 (67.6%) and Gim-05 (66.7%), while Gowata Trichoderma isolate 01 (Gow-01) isolate showed the lowest (42.2%) mean inhibitory effect restricting it almost completely in plates as compared to the control consisting of F. xylarioides growing alone. Gimbo Trichoderma isolate 05 (Gim-T05) produced zones of inhibition which is an indicative of the production of secondary metabolite(s) inhibiting the mycelial growth of F. xylarioides. Thus, the use of novel isolates of Trichoderma with efficient antagonistic capacity against F. xylarioides is a promising alternative strategy to pesticides for coffee wilt disease management. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/19023 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Antagonism | en_US |
| dc.subject | Coffee Arabica | en_US |
| dc.subject | Endophytes | en_US |
| dc.subject | Ph | en_US |
| dc.subject | Temperature | en_US |
| dc.title | Isolation and Characterization of Endophytic Trichoderma Isolates for Antagonistic Activity Against Coffee Wilt Disease (Gibberella Xylarioides) in Keffa Zone, Southwestern Ethiopia | en_US |
| dc.type | Thesis | en_US |