Fungal Pathogens Associated With Roselle (Hibiscus sabdariffa) in Penang, And Controls
| dc.contributor.author | Eslaminejad, Touba | |
| dc.date.accessioned | 2018-08-06T06:27:54Z | |
| dc.date.available | 2018-08-06T06:27:54Z | |
| dc.date.issued | 2011-02 | |
| dc.description.abstract | The main objective of this study was to identify and characterize fungal pathogens associated with Roselle diseases in Penang, and to study their control. A total of 200 fungal isolates were obtained from 90 samples of symptomatic Roselle tissues. The isolates were identified based on cultural and morphological characteristics, as well as their pathogenicity. The fungal pathogen most frequently isolated was Phoma exigua (present in 45 % of the samples collected), followed by Fusarium nygamai (25 %), Rhizoctonia solani (19 %) and F. camptoceras (11 %). Pathogenicity tests showed that P. exigua, F. nygamai, F. camptoceras and R. solani were able to infect both wounded and unwounded seedlings with different degrees of severity as indicated by the Disease Severity (DS). R. solani was the most pathogenic fungus affecting both wounded and unwounded Roselle seedlings, followed by P. exigua that was highly pathogenic on wounded seedlings. F. nygamai was less pathogenic while the least pathogenic fungus, F. camptoceras, infected only the unwounded seedlings but, surprisingly, not the wounded plants. The potential of Trichoderma viride as a bio control agent was evaluated in vitro against P. exigua, F. nygamai and R. solani using the dual culture technique. Volatile and non-volatile inhibitors of Trichoderma were also evaluated for this purpose. T. viride was shown to have a marked inhibitory effect on the tested pathogens in the dual culture experiments. Maximum inhibition occurred against F. nygamai, with 78.80 % reduction in mycelial radial growth. The three pathogens, P. exigua, F. nygamai and R. solani were also found to be susceptible to the volatile inhibitors produced by T. viride, giving rise to growth inhibition of about 68 % in each case. When T. viride non-volatile metabolites were tested against the pathogens, maximum inhibition occurred against R. solani (73.95 % mycelial growth inhibition), followed by P. exigua (37.17 % inhibition). | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/6202 | |
| dc.language.iso | en | en_US |
| dc.publisher | Universiti Sains Malaysia | en_US |
| dc.subject | Characterize fungal pathogens associated | en_US |
| dc.subject | with Roselle diseases in Penang | en_US |
| dc.title | Fungal Pathogens Associated With Roselle (Hibiscus sabdariffa) in Penang, And Controls | en_US |
| dc.type | Thesis | en_US |