First report of Curvularia lunata associated with stem disease of cassava
During surveys covering 60 cassava (Manihot esculenta Crantz) fields, randomly selected (between latitude 4°55′N and 8°16′N) in south Ghana, and 27 fields in southeast (between 4°50′N and 7°56′N) Nigeria, 8-month-old or older stems of some cassava genotypes were found to be covered by grayish brown...
| Autores principales: | , , , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
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Scientific Societies
1997
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| Acceso en línea: | https://hdl.handle.net/10568/98649 |
| _version_ | 1855514175656165376 |
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| author | Msikita, W. Yaninek, John S. Ahounou, M. Baimey, H. Fagbemissi, R. |
| author_browse | Ahounou, M. Baimey, H. Fagbemissi, R. Msikita, W. Yaninek, John S. |
| author_facet | Msikita, W. Yaninek, John S. Ahounou, M. Baimey, H. Fagbemissi, R. |
| author_sort | Msikita, W. |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | During surveys covering 60 cassava (Manihot esculenta Crantz) fields, randomly selected (between latitude 4°55′N and 8°16′N) in south Ghana, and 27 fields in southeast (between 4°50′N and 7°56′N) Nigeria, 8-month-old or older stems of some cassava genotypes were found to be covered by grayish brown lesions, predominantly on lignified portions of stems. Field disease incidence ranged from 0 to 80%, and severity from no disease to highly affected (>15 lesions per stem). To identify the pathogen, infected stem portions were cut out, surface disinfected, and cultured on potato dextrose agar (PDA) acidified with 0.4% (vol/vol) lactic acid. After 1 week, mycelia, conidiophores, and conidia were observed under a microscope, and the pathogen was identified as Curvularia lunata(Wakk.) Boedijn (confirmed also by the International My-cological Institute, Surrey, U.K.). To complete Koch's postulates, stem pieces of four cassava cultivars (Agric, Tchukunochi, TMS 30572, and Ben 86052), were disinfected in hot water (52°C for 5 min), transplanted in sterilized sand, and maintained in a greenhouse under natural light at 28 to 30°C. Before planting, five stems were wound inoculated (sliced with an epidermal scalpel) just above nodes, and a 5-mm-diameter PDA mycelial plug of C. lunata was applied to each wound or directly to unwounded nodes. Stems were then kept in a plastic bag for 24 h before planting. For each cultivar, five control stem pieces were similarly wounded but not treated with PDA plugs. All plants were maintained under >90% relative humidity. Control plants remained symptom-free whereas lesions and bud necrosis similar to field symptoms were observed on all inoculated plants within 1 month. Symptom development was quicker (2 to 3 weeks) on wound-inoculated than on nonwounded stems. Mortality of artificially wound-inoculated buds ranged between 30 and 100%, depending on genotype and manner of inoculation. Artificially infected stem and bud portions plated on PDA consistently yielded C. lunata. Bud sprouting of naturally infected cuttings was monitored over a period of 4 weeks after stem planting. When buds were completely colonized, sprouting was completely inhibited. However, partially colonized buds sprouted, but growth was reduced by 20 to 50% (depending on genotype), compared with healthy stems. This is the first report of C. lunata pathogenic on cassava. |
| format | Journal Article |
| id | CGSpace98649 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 1997 |
| publishDateRange | 1997 |
| publishDateSort | 1997 |
| publisher | Scientific Societies |
| publisherStr | Scientific Societies |
| record_format | dspace |
| spelling | CGSpace986492024-05-15T05:11:13Z First report of Curvularia lunata associated with stem disease of cassava Msikita, W. Yaninek, John S. Ahounou, M. Baimey, H. Fagbemissi, R. cassava curvularia During surveys covering 60 cassava (Manihot esculenta Crantz) fields, randomly selected (between latitude 4°55′N and 8°16′N) in south Ghana, and 27 fields in southeast (between 4°50′N and 7°56′N) Nigeria, 8-month-old or older stems of some cassava genotypes were found to be covered by grayish brown lesions, predominantly on lignified portions of stems. Field disease incidence ranged from 0 to 80%, and severity from no disease to highly affected (>15 lesions per stem). To identify the pathogen, infected stem portions were cut out, surface disinfected, and cultured on potato dextrose agar (PDA) acidified with 0.4% (vol/vol) lactic acid. After 1 week, mycelia, conidiophores, and conidia were observed under a microscope, and the pathogen was identified as Curvularia lunata(Wakk.) Boedijn (confirmed also by the International My-cological Institute, Surrey, U.K.). To complete Koch's postulates, stem pieces of four cassava cultivars (Agric, Tchukunochi, TMS 30572, and Ben 86052), were disinfected in hot water (52°C for 5 min), transplanted in sterilized sand, and maintained in a greenhouse under natural light at 28 to 30°C. Before planting, five stems were wound inoculated (sliced with an epidermal scalpel) just above nodes, and a 5-mm-diameter PDA mycelial plug of C. lunata was applied to each wound or directly to unwounded nodes. Stems were then kept in a plastic bag for 24 h before planting. For each cultivar, five control stem pieces were similarly wounded but not treated with PDA plugs. All plants were maintained under >90% relative humidity. Control plants remained symptom-free whereas lesions and bud necrosis similar to field symptoms were observed on all inoculated plants within 1 month. Symptom development was quicker (2 to 3 weeks) on wound-inoculated than on nonwounded stems. Mortality of artificially wound-inoculated buds ranged between 30 and 100%, depending on genotype and manner of inoculation. Artificially infected stem and bud portions plated on PDA consistently yielded C. lunata. Bud sprouting of naturally infected cuttings was monitored over a period of 4 weeks after stem planting. When buds were completely colonized, sprouting was completely inhibited. However, partially colonized buds sprouted, but growth was reduced by 20 to 50% (depending on genotype), compared with healthy stems. This is the first report of C. lunata pathogenic on cassava. 1997-01 2018-12-19T07:01:11Z 2018-12-19T07:01:11Z Journal Article https://hdl.handle.net/10568/98649 en Limited Access Scientific Societies Msikita, W., Yaninek, J.S., Ahounou, M., Baimey, H. & Fagbemissi, R. (1997). First report of Curvularia lunata associated with stem disease of cassava. Plant Disease, 81(1), 112-112. |
| spellingShingle | cassava curvularia Msikita, W. Yaninek, John S. Ahounou, M. Baimey, H. Fagbemissi, R. First report of Curvularia lunata associated with stem disease of cassava |
| title | First report of Curvularia lunata associated with stem disease of cassava |
| title_full | First report of Curvularia lunata associated with stem disease of cassava |
| title_fullStr | First report of Curvularia lunata associated with stem disease of cassava |
| title_full_unstemmed | First report of Curvularia lunata associated with stem disease of cassava |
| title_short | First report of Curvularia lunata associated with stem disease of cassava |
| title_sort | first report of curvularia lunata associated with stem disease of cassava |
| topic | cassava curvularia |
| url | https://hdl.handle.net/10568/98649 |
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