... The disease, locally known as corky bark or scab, is associated with severe losses of commerc... more ... The disease, locally known as corky bark or scab, is associated with severe losses of commercial pincushion (Leucosper-mum R. Br.) (Lsp.) plantings. The causal agent was identified as a species of Elsinoe but was never for-mally described (Benic and Knox-Davies 1983). ...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Indigenous leafy vegetables such as the spider plant (Cleome gynandra L.) can play an important r... more Indigenous leafy vegetables such as the spider plant (Cleome gynandra L.) can play an important role in alleviating malnutrition and providing a source of income to smallholder growers. In South Africa, the spider plant is often harvested from the wild. There is lack of information regarding the perceptions of end-users about this indigenous leafy vegetable in many regions of South Africa. Therefore, this study was designed to evaluate the perceptions of local communities about the spider plant in Limpopo Province (South Africa). This information on the perception of spider plant by end-users will serve as a prerequisite to establish a breeding programme, strategies to conserve the vegetable and to establish commercial production of this vegetable. Questionnaires were administered to households in each of the five districts in Limpopo Province targeting a wide range of end-users. Their consumption patterns, availability and level of knowledge of spider plant was assessed. Chi-square tests were used to assess the differences in perceptions and consumption patterns. The results showed that some of the communities relied on harvesting the vegetable spider plant from the homestead for consumption. There was no commercial seed production of this vegetable in these communities. The highest consumption ([ 50%) of the vegetable was observed in Waterberg and Sekhukhune districts. The results also showed that the age of consumers influenced dietary preferences with the old people preferring this leafy vegetable more than the young people. The bitter taste of the vegetable appeared to deter some potential endusers. These results showed that there is potential to cultivate the spider plant as a crop and to improve the taste of the vegetable. In addition, good quality seed could improve the production of the vegetable.
Dry core rot of apple (DCR) and Alternaria black rot of citrus (ABR) have in the past respectivel... more Dry core rot of apple (DCR) and Alternaria black rot of citrus (ABR) have in the past respectively been ascribed to Alternaria alternata and A. citri. In recent years, however, it has been speculated that several other species of Alternaria could also be associated with these diseases. In an attempt to elucidate the identity of these taxa, 25 isolates associated with DCR, and 26 isolates associated with ABR were selected for molecular characterisation. Nucleotide sequences of 1116 sites including the histone gene section and the internal transcribed spacers (ITS 1 and 2) of the rRNA gene were determined for these isolates. The gene trees generated from the individual and combined data sets using maximum parsimony, maximum likelihood and neighbour-joining analysis methods distinguished five clades with strong bootstrap support, namely Alternaria sp., A. arborescens, A. infectoria, A. tenuissima, and a clade containing isolates variable in morphology, referred to as the Alternaria group. In the alignment of the combined ITS and histone data set, unique transition/transversion substitutions, as well as positional insertions and deletions were observed for each of the above clades. In addition, key sequences in the form of serial composing nucleotides in both the ITS and histone sections of the alignment were also discovered for the molecular identification of A. arborescens, A. infectoria and A. tenuissima. The final phylogeny also indicated that no host specificity existed among the species associated with these two post-harvest disease complexes. Contrary to the host specificity observed on leaf diseases of these hosts in the field, it appears that the post-harvest diseases are the result of adverse storage conditions and opportunism of different small-spored Alternaria spp.
... Mycologia 71, 392-401. GRA Mchau and MD Coffey I299 Alizadeh, A. & Tsao, PH (1985). ... A... more ... Mycologia 71, 392-401. GRA Mchau and MD Coffey I299 Alizadeh, A. & Tsao, PH (1985). ... Annual Review of Phytopathotogy 30, 173-200. Campelo, AM & Luz, ED (1981). Etiologia da podrid~o pardo do cacaueiro nos estados da Bahia e Espfrito Santo, Brasil. ...
Unidentified strains of Cylindrocladium that were baited from soil in the Amazonas state of Brazi... more Unidentified strains of Cylindrocladium that were baited from soil in the Amazonas state of Brazil or isolated from Adiantum in the Netherlands were examined morphologically and analysed phylogenetically in comparison with reference strains. Phylogenetic trees inferred from the 5.8S subunit and flanking internal transcribed spacers (ITS1 and ITS2) of rDNA, as well as the beta-tubulin gene, separated species in accordance with their morphological features and characteristics. Although species differences based on ITS sequences were consistent, there were only a few informative sites available, making it difficult to clearly identify the unknown strains. Better resolution in separation of species was achieved from the beta-tubulin data. The strains baited from soil in Brazil were found to represent two species, namely Cylindrocladium gracile (Bugnic.) Boesew. and Cylindrocladium pseudogracile Crous. Morphologically, these two species are similar, except that the latter has slightly na...
Isozyme and morphological data were obtained for 93 isolates of P. palmivora and six described as... more Isozyme and morphological data were obtained for 93 isolates of P. palmivora and six described as P. arecae. Sporangial shape for both species ranged from spherical to ellipsoid with a high percentage of sporangia predominantly ellipsoid with a broad base and a short occluded pedicel less than 5 I-Im in length. Fourteen enzymes stained in starch gels yielding 17 putative loci, 11 of which were monomorphic, the remainder being polymorphic (GPI. HEX2, IDHI, MDH1, PEP and SOD). Phosphoglucose isomerase (GPl) and isocitric dehydrogenase (IDH1) were the most variable loci. Isozyme analysis of the 99 isolates revealed 18 electrophoretic types (ETs). Isolates of P. arecae clustered with P. palmivora in ET7 and ET8, the most common ETs found in P. palmivora. Considerable genetic diversity was found amongst P. palmivora isolates from coconut (Cocos nucifera) with 8 ETs, durian (Durio zibethinus) with 5 ETs and other non-cacao hosts from Indonesia, Malaysia, Philippines and Thailand. Since coconut and durian are indigenous to the region, a southeast Asian origin for P. palmivora seems probable. Finally, since no Significant differences were found in either morphology or isozymes between isolates of P. palmivora and P. arecae, this study provides definitive evidence that the two species are conspecific.
Horticultural practices and quality of bush tea (Athrixia phylicoides DC.) are critical for herba... more Horticultural practices and quality of bush tea (Athrixia phylicoides DC.) are critical for herbal tea industrialization. The objective of the current study was to determine the effect of selected shade nets and seasonal variation on plant growth and development, and hydroxycinnamic acid content of field-grown bush tea. The trial was laid out in a randomized complete block design consisting of three shade nets (black, green, and white) and control or full sunlight with three different light intensities (40%, 50%, and 80%) replicated three times. Proportion of intercepted radiation by the canopy, chlorophyll content, plant height, and fresh and dry mass were measured, and hydroxycinnamic acid accumulation was determined. In addition, hydroxycinnamic acid composition was determined using liquid chromatography linked to mass spectrometry (LC-MS). The application of shade nets resulted in plant growth and yield reduction as compared with the plants exposed to full sunlight during summer...
Spider plant (Cleome gynandra L.) is an indigenous leafy vegetable that is a rich source of miner... more Spider plant (Cleome gynandra L.) is an indigenous leafy vegetable that is a rich source of minerals, proteins, vitamins, flavonoids, antioxidants and many other compounds. Morphological characterization of the germplasm for optimal genetic exploitation is limited by environmental factors. The objective of this study was to determine the degree of genetic diversity between exotic and local spider plant accessions using molecular markers. The spider plant germplasm consisted of 18 local and exotic accessions. Seven polymorphic simple sequence repeat (SSR) markers were used in the study. The SSR marker combinations revealed a total of 46 alleles at 7 loci, with an average of 6.57 alleles per locus. An average polymorphic information index of 0.69 was recorded. According to Nei’s genetic distance analysis, low population differentiation was observed between the local and exotic spider plant accessions, which was indicated by a low fixation index value of 0.024 and a high Nm (10.20). An...
... The disease, locally known as corky bark or scab, is associated with severe losses of commerc... more ... The disease, locally known as corky bark or scab, is associated with severe losses of commercial pincushion (Leucosper-mum R. Br.) (Lsp.) plantings. The causal agent was identified as a species of Elsinoe but was never for-mally described (Benic and Knox-Davies 1983). ...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Indigenous leafy vegetables such as the spider plant (Cleome gynandra L.) can play an important r... more Indigenous leafy vegetables such as the spider plant (Cleome gynandra L.) can play an important role in alleviating malnutrition and providing a source of income to smallholder growers. In South Africa, the spider plant is often harvested from the wild. There is lack of information regarding the perceptions of end-users about this indigenous leafy vegetable in many regions of South Africa. Therefore, this study was designed to evaluate the perceptions of local communities about the spider plant in Limpopo Province (South Africa). This information on the perception of spider plant by end-users will serve as a prerequisite to establish a breeding programme, strategies to conserve the vegetable and to establish commercial production of this vegetable. Questionnaires were administered to households in each of the five districts in Limpopo Province targeting a wide range of end-users. Their consumption patterns, availability and level of knowledge of spider plant was assessed. Chi-square tests were used to assess the differences in perceptions and consumption patterns. The results showed that some of the communities relied on harvesting the vegetable spider plant from the homestead for consumption. There was no commercial seed production of this vegetable in these communities. The highest consumption ([ 50%) of the vegetable was observed in Waterberg and Sekhukhune districts. The results also showed that the age of consumers influenced dietary preferences with the old people preferring this leafy vegetable more than the young people. The bitter taste of the vegetable appeared to deter some potential endusers. These results showed that there is potential to cultivate the spider plant as a crop and to improve the taste of the vegetable. In addition, good quality seed could improve the production of the vegetable.
Dry core rot of apple (DCR) and Alternaria black rot of citrus (ABR) have in the past respectivel... more Dry core rot of apple (DCR) and Alternaria black rot of citrus (ABR) have in the past respectively been ascribed to Alternaria alternata and A. citri. In recent years, however, it has been speculated that several other species of Alternaria could also be associated with these diseases. In an attempt to elucidate the identity of these taxa, 25 isolates associated with DCR, and 26 isolates associated with ABR were selected for molecular characterisation. Nucleotide sequences of 1116 sites including the histone gene section and the internal transcribed spacers (ITS 1 and 2) of the rRNA gene were determined for these isolates. The gene trees generated from the individual and combined data sets using maximum parsimony, maximum likelihood and neighbour-joining analysis methods distinguished five clades with strong bootstrap support, namely Alternaria sp., A. arborescens, A. infectoria, A. tenuissima, and a clade containing isolates variable in morphology, referred to as the Alternaria group. In the alignment of the combined ITS and histone data set, unique transition/transversion substitutions, as well as positional insertions and deletions were observed for each of the above clades. In addition, key sequences in the form of serial composing nucleotides in both the ITS and histone sections of the alignment were also discovered for the molecular identification of A. arborescens, A. infectoria and A. tenuissima. The final phylogeny also indicated that no host specificity existed among the species associated with these two post-harvest disease complexes. Contrary to the host specificity observed on leaf diseases of these hosts in the field, it appears that the post-harvest diseases are the result of adverse storage conditions and opportunism of different small-spored Alternaria spp.
... Mycologia 71, 392-401. GRA Mchau and MD Coffey I299 Alizadeh, A. & Tsao, PH (1985). ... A... more ... Mycologia 71, 392-401. GRA Mchau and MD Coffey I299 Alizadeh, A. & Tsao, PH (1985). ... Annual Review of Phytopathotogy 30, 173-200. Campelo, AM & Luz, ED (1981). Etiologia da podrid~o pardo do cacaueiro nos estados da Bahia e Espfrito Santo, Brasil. ...
Unidentified strains of Cylindrocladium that were baited from soil in the Amazonas state of Brazi... more Unidentified strains of Cylindrocladium that were baited from soil in the Amazonas state of Brazil or isolated from Adiantum in the Netherlands were examined morphologically and analysed phylogenetically in comparison with reference strains. Phylogenetic trees inferred from the 5.8S subunit and flanking internal transcribed spacers (ITS1 and ITS2) of rDNA, as well as the beta-tubulin gene, separated species in accordance with their morphological features and characteristics. Although species differences based on ITS sequences were consistent, there were only a few informative sites available, making it difficult to clearly identify the unknown strains. Better resolution in separation of species was achieved from the beta-tubulin data. The strains baited from soil in Brazil were found to represent two species, namely Cylindrocladium gracile (Bugnic.) Boesew. and Cylindrocladium pseudogracile Crous. Morphologically, these two species are similar, except that the latter has slightly na...
Isozyme and morphological data were obtained for 93 isolates of P. palmivora and six described as... more Isozyme and morphological data were obtained for 93 isolates of P. palmivora and six described as P. arecae. Sporangial shape for both species ranged from spherical to ellipsoid with a high percentage of sporangia predominantly ellipsoid with a broad base and a short occluded pedicel less than 5 I-Im in length. Fourteen enzymes stained in starch gels yielding 17 putative loci, 11 of which were monomorphic, the remainder being polymorphic (GPI. HEX2, IDHI, MDH1, PEP and SOD). Phosphoglucose isomerase (GPl) and isocitric dehydrogenase (IDH1) were the most variable loci. Isozyme analysis of the 99 isolates revealed 18 electrophoretic types (ETs). Isolates of P. arecae clustered with P. palmivora in ET7 and ET8, the most common ETs found in P. palmivora. Considerable genetic diversity was found amongst P. palmivora isolates from coconut (Cocos nucifera) with 8 ETs, durian (Durio zibethinus) with 5 ETs and other non-cacao hosts from Indonesia, Malaysia, Philippines and Thailand. Since coconut and durian are indigenous to the region, a southeast Asian origin for P. palmivora seems probable. Finally, since no Significant differences were found in either morphology or isozymes between isolates of P. palmivora and P. arecae, this study provides definitive evidence that the two species are conspecific.
Horticultural practices and quality of bush tea (Athrixia phylicoides DC.) are critical for herba... more Horticultural practices and quality of bush tea (Athrixia phylicoides DC.) are critical for herbal tea industrialization. The objective of the current study was to determine the effect of selected shade nets and seasonal variation on plant growth and development, and hydroxycinnamic acid content of field-grown bush tea. The trial was laid out in a randomized complete block design consisting of three shade nets (black, green, and white) and control or full sunlight with three different light intensities (40%, 50%, and 80%) replicated three times. Proportion of intercepted radiation by the canopy, chlorophyll content, plant height, and fresh and dry mass were measured, and hydroxycinnamic acid accumulation was determined. In addition, hydroxycinnamic acid composition was determined using liquid chromatography linked to mass spectrometry (LC-MS). The application of shade nets resulted in plant growth and yield reduction as compared with the plants exposed to full sunlight during summer...
Spider plant (Cleome gynandra L.) is an indigenous leafy vegetable that is a rich source of miner... more Spider plant (Cleome gynandra L.) is an indigenous leafy vegetable that is a rich source of minerals, proteins, vitamins, flavonoids, antioxidants and many other compounds. Morphological characterization of the germplasm for optimal genetic exploitation is limited by environmental factors. The objective of this study was to determine the degree of genetic diversity between exotic and local spider plant accessions using molecular markers. The spider plant germplasm consisted of 18 local and exotic accessions. Seven polymorphic simple sequence repeat (SSR) markers were used in the study. The SSR marker combinations revealed a total of 46 alleles at 7 loci, with an average of 6.57 alleles per locus. An average polymorphic information index of 0.69 was recorded. According to Nei’s genetic distance analysis, low population differentiation was observed between the local and exotic spider plant accessions, which was indicated by a low fixation index value of 0.024 and a high Nm (10.20). An...
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