Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata)
Thesis (PhD)--University of Pretoria, 2006.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Published: |
University of Pretoria
2013
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613688375017472 |
|---|---|
| access_status_str | Open Access |
| author2 | Aveling, Terry A.S. |
| author_browse | Aveling, Terry A.S. |
| author_facet | Aveling, Terry A.S. |
| collection | Thesis |
| dc_rights_str_mv | © 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (PhD)--University of Pretoria, 2006. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/30544 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:40:07.413Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/30544 Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) Aveling, Terry A.S. upetd@up.ac.za Kritzinger, Quenton Fb1 Fusarium proliferatum Germination Medicinal Fumonisins Vigna unguiculata Ultrastructure Storage Cowpea Antimicrobial Mycoflora Phytotoxic UCTD Thesis (PhD)--University of Pretoria, 2006. A survey involving 71 farmers from rural communities in Mpumalanga, South Africa was conducted to gather information regarding the importance and utilisation of cowpea. Cowpea was rated third most important in contributing to household security, preceded by maize and vegetable production. Cowpea was mainly produced for own consumption, as a source of income and as fodder for livestock to a lesser extent. The crop was used by 8.5% of the farmers for medicinal purposes. Results indicated that 20% of the farmers encountered problems with mouldiness during storage, with insect infestation to a lesser degree. Cowpea seed samples from South Africa and Benin, West Africa were analysed for seed mycoflora and various fungal genera, particularly Aspergillus, Phoma and Lasiodiplodia were recorded. The results indicated an array of Fusarium spp. including F. equiseti, F. chlamydosporum, F. graminearum, F. proliferatum, F. sambucinum, F. scirpi, F. semitectum and F. subglutinans. The seed samples and the F. proliferatum isolates, cultured on maize patty media, were analysed for fumonisin production. Samples were extracted with methanol/water (70:30) and cleaned-up on strong anion exchange solid phase extraction cartridges. High-performance liquid chromatography with pre-column derivatisation using o-phthaldialdehyde was used for the detection and quantification of FB1, FB2 and FB3. The cowpea cultivars from South Africa had levels of FB1 ranging between 0.12 – 0.61 µg/g. All the F. proliferatum isolates produced FB1, FB2 and FB3 with total fumonisin concentration levels between 0.80 - 25.30 µg/g. The highest level of FB1 detected was 16.86 µg/g. Surface-disinfected seeds were imbibed in sterile distilled water amended with FB1 to yield final concentrations of 10, 25, 50 and 100 ppm. Percentage germination was determined in paper towels according to the International Seed Testing Association (ISTA) rules. Root and shoot length was measured after 9 days. All the toxin concentrations significantly decreased seed germination whilst root and shoot elongation was inhibited by the 50 and 100 ppm concentrations. Embryonic seed tissue treated with FB1 indicated compaction of the protoplasm and separation of the plasma membrane from the cell wall. Lipid bodies accumulated and seemed to line the cell wall. Acetone and ethanol extracts of the leaves of two cowpea cultivars exhibited significant inhibition of the growth of fungal plant pathogens at 5.0 mg/ml, with the exception of Fusarium equiseti. The growth of some fungi, in particular Alternaria alternate, was also reduced by lower concentrations of certain extracts. Acetone extracts of the Bechwana White cultivar inhibited growth of Staphylococcus aureus and Enterococcus faecalis at 2.5 mg/ml and Bacillus cereus, B. subtilis and Enterobacter cloacae at 5.0 mg/ml. Ethanol extracts of the same cultivar showed antibacterial activity against E. faecalis and E. cloacae at 5.0 mg/ml. This study represents the first report on the natural occurrence of fumonisins on cowpea seed and the potential of F. proliferatum isolates from cowpea seed to produce fumonisins. The phytotoxic effects of FB1 on cowpea seeds as well as the antimicrobial potential of cowpea leaf extracts were demonstrated for the first time. Microbiology and Plant Pathology unrestricted 2013-09-07T19:19:40Z 2006-02-22 2013-09-07T19:19:40Z 2004-04-08 2006-02-22 2006-02-22 Thesis Kritzinger, Q 2004, Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata), PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/30544 > http://hdl.handle.net/2263/30544 http://upetd.up.ac.za/thesis/available/etd-02222006-103447/ © 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria |
| spellingShingle | Fb1 Fusarium proliferatum Germination Medicinal Fumonisins Vigna unguiculata Ultrastructure Storage Cowpea Antimicrobial Mycoflora Phytotoxic UCTD Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) |
| title | Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) |
| title_full | Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) |
| title_fullStr | Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) |
| title_full_unstemmed | Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) |
| title_short | Antimicrobial activity and fumonisins associated with cowpea (Vigna unguiculata) |
| title_sort | antimicrobial activity and fumonisins associated with cowpea vigna unguiculata |
| topic | Fb1 Fusarium proliferatum Germination Medicinal Fumonisins Vigna unguiculata Ultrastructure Storage Cowpea Antimicrobial Mycoflora Phytotoxic UCTD |
| url | http://hdl.handle.net/2263/30544 http://upetd.up.ac.za/thesis/available/etd-02222006-103447/ |