Arbuscular mycorrhizal fungi persist in dying Euphorbia ingens trees
- Vivas, M, Crous, C J, Dames, Joanna F, Van der Linde, J A, Coetzee, M P A, Roux, J
- Authors: Vivas, M , Crous, C J , Dames, Joanna F , Van der Linde, J A , Coetzee, M P A , Roux, J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
- Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
- Full Text:
- Date Issued: 2018
- Authors: Vivas, M , Crous, C J , Dames, Joanna F , Van der Linde, J A , Coetzee, M P A , Roux, J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
- Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
- Full Text:
- Date Issued: 2018
Assimilation of organic and inorganic nutrients by Erica root fungi from the fynbos ecosystem
- Bizabani, Christine, Dames, Joanna F
- Authors: Bizabani, Christine , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444079 , vital:74183 , https://doi.org/10.1016/j.funbio.2015.11.006
- Description: Erica dominate the fynbos ecosystem, which is characterized by acidic soils that are rich in organic matter. The ericaceae associate with ericoid mycorrhizal (ERM) fungi for survival. In this study fungal biomass accumulation in vitro was used to determine nutrient utilisation of various inorganic and organic substrates. This is an initial step towards establishment of the ecological roles of typical ERM fungi and other root fungi associated with Erica plants, with regard to host nutrition. Meliniomyces sp., Acremonium implicatum, Leohumicola sp., Cryptosporiopsis erica, Oidiodendron maius and an unidentified Helotiales fungus were selected from fungi previously isolated and identified from Erica roots. Sole nitrogen sources ammonium, nitrate, arginine and Bovine Serum Albumin (BSA) were tested. Meliniomyces and Leohumicola species were able to utilise BSA effectively. Phosphorus nutrition was tested using orthophosphate, sodium inositol hexaphosphate and DNA. Most isolates preferred orthophosphate. Meliniomyces sp. and A. implicatum were able to accumulate significant biomass using DNA. Carbon utilisation was tested using glucose, cellobiose, carboxymethylcellulose, pectin and tannic acid substrates. All fungal isolates produced high biomass on glucose and cellobiose. The ability to utilize organic nutrient sources in culture, illustrates their potential role of these fungi in host nutrition in the fynbos ecosystem.
- Full Text:
- Date Issued: 2016
- Authors: Bizabani, Christine , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444079 , vital:74183 , https://doi.org/10.1016/j.funbio.2015.11.006
- Description: Erica dominate the fynbos ecosystem, which is characterized by acidic soils that are rich in organic matter. The ericaceae associate with ericoid mycorrhizal (ERM) fungi for survival. In this study fungal biomass accumulation in vitro was used to determine nutrient utilisation of various inorganic and organic substrates. This is an initial step towards establishment of the ecological roles of typical ERM fungi and other root fungi associated with Erica plants, with regard to host nutrition. Meliniomyces sp., Acremonium implicatum, Leohumicola sp., Cryptosporiopsis erica, Oidiodendron maius and an unidentified Helotiales fungus were selected from fungi previously isolated and identified from Erica roots. Sole nitrogen sources ammonium, nitrate, arginine and Bovine Serum Albumin (BSA) were tested. Meliniomyces and Leohumicola species were able to utilise BSA effectively. Phosphorus nutrition was tested using orthophosphate, sodium inositol hexaphosphate and DNA. Most isolates preferred orthophosphate. Meliniomyces sp. and A. implicatum were able to accumulate significant biomass using DNA. Carbon utilisation was tested using glucose, cellobiose, carboxymethylcellulose, pectin and tannic acid substrates. All fungal isolates produced high biomass on glucose and cellobiose. The ability to utilize organic nutrient sources in culture, illustrates their potential role of these fungi in host nutrition in the fynbos ecosystem.
- Full Text:
- Date Issued: 2016
Beauveria and Metarhizium against false codling moth (Lepidoptera: Tortricidae): a step towards selecting isolates for potential development of a mycoinsecticide
- Coombes, Candice A, Hill, Martin P, Moore, Sean D, Dames, Joanna F, Fullard, T
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405757 , vital:70203 , xlink:href="https://hdl.handle.net/10520/EJC167505"
- Description: False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
- Full Text:
- Date Issued: 2015
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F , Fullard, T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405757 , vital:70203 , xlink:href="https://hdl.handle.net/10520/EJC167505"
- Description: False codling moth, Thaumatotibia leucotreta Meyrick (1912) (Lepidoptera: Tortricidae), can cause both pre- and post-harvest damage to citrus fruit. Not only can this result in reduced crop yield, but more importantly because of the moth's endemism to sub-Saharan Africa, it is classified as a phytosanitary pest by many export markets. An entire consignment of citrus may be rejected in the presence of a single moth (Moore 2012). Since the bulk of citrus fruit production in South Africa is exported, the control of T. leucotreta is critical (Citrus Growers Association, South Africa 2012). Traditionally, control has been achieved through the use of chemical insecticides; however, residue restrictions, resistance development and concerns about environmental pollution have substantially reduced the dependence on chemical pesticides in citrus. Research on T. leucotreta control has therefore focused on the use of biological organisms (e.g. parasitoids and viruses), which are used as control agents within an integrated pest management (IPM) programme in citrus. These biological control agents, however, only targeted the aboveground life stages of the pest, not the soil-dwelling life stages (late fifth instars, prepupae, pupae), which is the subject of this contribution (Moore 2012).
- Full Text:
- Date Issued: 2015
Biological control potential of ectomycorrhizal fungi against Fusarium circinatum on Pinus patula seedlings
- Chartier FitzGerald, Veronique C, Dames, Joanna F, Hawley, Grant L
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
- Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
- Full Text:
- Date Issued: 2020
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
- Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
- Full Text:
- Date Issued: 2020
Characterization of arbuscular mycorrhizal fungal species associating with Zea mays
- Maússe-Sitoe, Silvia, Dames, Joanna F
- Authors: Maússe-Sitoe, Silvia , Dames, Joanna F
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440339 , vital:73775 , https://doi.org/10.3389/fpls.2024.1345229
- Description: Taxonomic identification of arbuscular mycorrhizal (AM) fungal spores extracted directly from the field is sometimes difficult because spores are often degraded or parasitized by other organisms. Single-spore inoculation of a suitable host plant allows for establishing monosporic cultures of AM fungi. This study aimed to propagate AM fungal spores isolated from maize soil using single spores for morphological characterization. First, trap cultures were established to trigger the sporulation of AM fungal species. Second, trap cultures were established with individual morphotypes by picking up only one spore under a dissecting microscope and transferring it to a small triangle of sterilized filter paper, which was then carefully inoculated below a root from germinated sorghum seeds in each pot and covered with a sterile substrate. All pots were placed in sunbags and maintained in a plant growth room for 120 days.
- Full Text:
- Date Issued: 2024
- Authors: Maússe-Sitoe, Silvia , Dames, Joanna F
- Date: 2024
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440339 , vital:73775 , https://doi.org/10.3389/fpls.2024.1345229
- Description: Taxonomic identification of arbuscular mycorrhizal (AM) fungal spores extracted directly from the field is sometimes difficult because spores are often degraded or parasitized by other organisms. Single-spore inoculation of a suitable host plant allows for establishing monosporic cultures of AM fungi. This study aimed to propagate AM fungal spores isolated from maize soil using single spores for morphological characterization. First, trap cultures were established to trigger the sporulation of AM fungal species. Second, trap cultures were established with individual morphotypes by picking up only one spore under a dissecting microscope and transferring it to a small triangle of sterilized filter paper, which was then carefully inoculated below a root from germinated sorghum seeds in each pot and covered with a sterile substrate. All pots were placed in sunbags and maintained in a plant growth room for 120 days.
- Full Text:
- Date Issued: 2024
Current developments in arbuscular mycorrhizal fungi research and its role in salinity stress alleviation a biotechnological perspective
- Kumar, Ashwani, Dames, Joanna F, Gupta, Aditi, Sharma, Satyawati, Gilbert, Jack A, Ahmad, Parvaiz
- Authors: Kumar, Ashwani , Dames, Joanna F , Gupta, Aditi , Sharma, Satyawati , Gilbert, Jack A , Ahmad, Parvaiz
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443998 , vital:74177 , https://doi.org/10.3109/07388551.2014.899964
- Description: Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, “omics” technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production.
- Full Text:
- Date Issued: 2015
- Authors: Kumar, Ashwani , Dames, Joanna F , Gupta, Aditi , Sharma, Satyawati , Gilbert, Jack A , Ahmad, Parvaiz
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443998 , vital:74177 , https://doi.org/10.3109/07388551.2014.899964
- Description: Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, “omics” technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production.
- Full Text:
- Date Issued: 2015
Detection of plant growth enhancing features in psychrotolerant yeasts from Patagonia (Argentina)
- Mestre, María C, Fontenla, Sonia, Bruzone, Marie C, Fernández, Natalia V, Dames, Joanna F
- Authors: Mestre, María C , Fontenla, Sonia , Bruzone, Marie C , Fernández, Natalia V , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448581 , vital:74744 , https://doi.org/10.1002/jobm.201500728
- Description: This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest‐Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin‐like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin‐like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern‐Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold‐temperate regions.
- Full Text:
- Date Issued: 2016
- Authors: Mestre, María C , Fontenla, Sonia , Bruzone, Marie C , Fernández, Natalia V , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448581 , vital:74744 , https://doi.org/10.1002/jobm.201500728
- Description: This study explores the biotechnological potential for plant production of twelve psychrotolerant yeasts strains from Northwest‐Patagonia. These strains were isolated from different substrates associated with Nothofagus sp. in native forests and Vaccinium sp. in a commercial plantation. Yeasts characterization was performed using in vitro assays to evaluate the production of auxin‐like compounds and siderophores, ability to solubilize inorganic phosphate and to reduce common plant pathogen growth. Strain YF8.3 identified as Aureobasidium pullullans was the main producer of auxin‐like and siderophores compounds. Phosphate solubilization was a characteristic observed by strains L8.12 and CRUB1775 identified as Holtermaniella takashimae and Candida maritima, respectively. Different yeast strains were able to inhibit the growth of Verticillium dahliae PPRI5569 and Pythium aphanidermatum PPRI 9009, but they all failed to inhibit the growth of Fusarium oxysporum PPRI5457. The present study, suggests that yeasts present in different environments in Northwestern‐Patagonian have physiological in vitro features which may influence plant growth. These results are promising for the developing of biological products based on Patagonian yeasts for plant production in cold‐temperate regions.
- Full Text:
- Date Issued: 2016
Development of high yielding strain of Pleurotus tuber-regium fructification, nutritional and phylogenetic studies
- Bamigboye, Comfort O, Oloke, Julius K, Dames, Joanna F
- Authors: Bamigboye, Comfort O , Oloke, Julius K , Dames, Joanna F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448595 , vital:74745 , https://doi.org/10.1007/s13197-019-03786-7
- Description: Mushrooms are nutritionally rich, healthy and medicinal. Pleurotus tuber-regium (Fr.) is one of the nutritious medicinal mushroom found in the tropics and subtropics, but with history of slow growth and low sclerotia yield. In this study, mutants were created by mycelia exposure to ultraviolet irradiation (at a wavelength of 254 nm and a distance of 45 cm), for 3 h and sub-cultured at 30 min interval. The DNA from the wild and mutant strains were extracted, PCR amplified and sequenced. A phylogenetic tree was constructed to show the degree of similarity and differences between the wild and the mutant strains. Fructification studies were conducted on Rhodes grass straw and sawdust to determine the viability of the mutant strains and any nutritional improvement. The wild strain of P. tuber-regium and mutant produced at 30 min (Pt30) cultivated on sawdust and Rhodes straw, yielded sclerotia with biological efficiency of 8.8 and 47.6% respectively. Proximate analysis of the sclerotium showed that the mutant, Pt30, had improved nutritional compositions compared to the wild strain with a total non-structural carbohydrate concentration of 2.41 g as against 0.93 g. Conclusively in this study, better strains of P. tuber-regium were produced with faster growth rate, higher mycelia ramification rate on lignocellulosic substrate and a higher sclerotia yield than the wild P. tuber-regium. It was also established that mutagenesis is capable of improving P. tuber-regium for a successful commercial venture in sclerotia production.
- Full Text:
- Date Issued: 2019
- Authors: Bamigboye, Comfort O , Oloke, Julius K , Dames, Joanna F
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448595 , vital:74745 , https://doi.org/10.1007/s13197-019-03786-7
- Description: Mushrooms are nutritionally rich, healthy and medicinal. Pleurotus tuber-regium (Fr.) is one of the nutritious medicinal mushroom found in the tropics and subtropics, but with history of slow growth and low sclerotia yield. In this study, mutants were created by mycelia exposure to ultraviolet irradiation (at a wavelength of 254 nm and a distance of 45 cm), for 3 h and sub-cultured at 30 min interval. The DNA from the wild and mutant strains were extracted, PCR amplified and sequenced. A phylogenetic tree was constructed to show the degree of similarity and differences between the wild and the mutant strains. Fructification studies were conducted on Rhodes grass straw and sawdust to determine the viability of the mutant strains and any nutritional improvement. The wild strain of P. tuber-regium and mutant produced at 30 min (Pt30) cultivated on sawdust and Rhodes straw, yielded sclerotia with biological efficiency of 8.8 and 47.6% respectively. Proximate analysis of the sclerotium showed that the mutant, Pt30, had improved nutritional compositions compared to the wild strain with a total non-structural carbohydrate concentration of 2.41 g as against 0.93 g. Conclusively in this study, better strains of P. tuber-regium were produced with faster growth rate, higher mycelia ramification rate on lignocellulosic substrate and a higher sclerotia yield than the wild P. tuber-regium. It was also established that mutagenesis is capable of improving P. tuber-regium for a successful commercial venture in sclerotia production.
- Full Text:
- Date Issued: 2019
Ectomycorrhizas in association with Pinus patula in Sabie, South Africa
- Hawley, Greer L, Taylor, A F S, Dames, Joanna F
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
- Full Text:
- Date Issued: 2008
- Authors: Hawley, Greer L , Taylor, A F S , Dames, Joanna F
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6475 , http://hdl.handle.net/10962/d1006163 , http://www.scielo.org.za/scielo.php?pid=S0038-23532008000400011&script=sci_arttext
- Description: Forestry is an economically important industry in South Africa,involving extensive exotic plantations of Eucalyptus, Pinus and Acacia species. These tree species have fungal associations, such as ectomycorrhizas, that have become locally naturalized. The forestry industry is increasingly faced with problems of long-term sustainability, increasing soil acidity and depletion of soil nutrients. It is, therefore, essential that the fundamental importance of the ectomycorrhizal (ECM) symbioses in the nutrient cycling, growth, health and survival of these tree species should not be ignored. Research on the species diversity of ECM fungi associated with forestry plant species has been hampered by the difficulty of identifying the fungi involved in the symbiosis. This investigation focused on the ECM fungi associated with Pinus patula (Schlecht. et Cham.) grown in managed plantations in the Sabie region, Mpumalanga province, South Africa. ECM roots were morphotyped and DNA was extracted. The internal transcribed spacer (ITS) region was amplified using the ITS 1F and ITS 4 primers. The sequences were BLASTed using the GenBank and UNITE databases. Twenty-seven extractions were successfully amplified representing 17 different morphotypes. Of the 27 sequences, 21 were identified as ECM fungi and, from the BLAST results, eleven different ECM species could be identified. Selected ECM root types were morphologically and anatomically described according to root morphology, mantle structure, specialized hyphae and rhizomorph arrangement. Seven dominant field types were described and identified as two Amanita species, Scleroderma citrinum, a suilloid species, Thelephora terrestris, a tometelloid species and one resembled an Albatrellus species.
- Full Text:
- Date Issued: 2008
Effect of conventional and organic orchard floor management practices on arbuscular mycorrhizal fungi in a ‘Cripp’s Pink’/M7 apple orchard soil
- Meyer, André H, Wooldridge, John, Dames, Joanna F
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
- Full Text:
- Date Issued: 2015
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
- Full Text:
- Date Issued: 2015
Effects of inoculating Lachnum and Cadophora isolates on the growth of Vaccinium corymbosum
- Mbizabani, Christine, Dames, Joanna F
- Authors: Mbizabani, Christine , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444024 , vital:74179 , https://doi.org/10.1016/j.micres.2015.08.005
- Description: The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect.
- Full Text:
- Date Issued: 2015
- Authors: Mbizabani, Christine , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444024 , vital:74179 , https://doi.org/10.1016/j.micres.2015.08.005
- Description: The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect.
- Full Text:
- Date Issued: 2015
Entomopathogenic fungi as control agents of Thaumatotibia leucotreta in citrus orchards: field efficacy and persistence
- Coombes, Candice A, Hill, Martin P, Moore, Sean D, Dames, Joanna F
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417956 , vital:71497 , xlink:href="https://doi.org/10.1007/s10526-016-9756-x"
- Description: Entomopathogenic fungal isolates Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) strain G Ar 17 B3 and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) strain FCM Ar 23 B3 have been identified as effective control agents of the important citrus pest Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) wandering fifth instars under laboratory conditions. This study is the first report on the ability of these isolates to persist and reduce T. leucotreta infestation in commercial citrus orchards in South Africa. A reduction in pest infestation of between 28 and 82 % upon trial completion was reported. Both isolates were recovered from soil samples collected five months post-application with high host density and moderate to high soil moisture favouring recovery. Low soil moisture negatively influenced the persistence of both isolates and the control efficiency of B. bassiana. These results provide evidence and support for the future use of these isolates against T. leucotreta thus warranting further investigation.
- Full Text:
- Date Issued: 2016
- Authors: Coombes, Candice A , Hill, Martin P , Moore, Sean D , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417956 , vital:71497 , xlink:href="https://doi.org/10.1007/s10526-016-9756-x"
- Description: Entomopathogenic fungal isolates Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) strain G Ar 17 B3 and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae) strain FCM Ar 23 B3 have been identified as effective control agents of the important citrus pest Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) wandering fifth instars under laboratory conditions. This study is the first report on the ability of these isolates to persist and reduce T. leucotreta infestation in commercial citrus orchards in South Africa. A reduction in pest infestation of between 28 and 82 % upon trial completion was reported. Both isolates were recovered from soil samples collected five months post-application with high host density and moderate to high soil moisture favouring recovery. Low soil moisture negatively influenced the persistence of both isolates and the control efficiency of B. bassiana. These results provide evidence and support for the future use of these isolates against T. leucotreta thus warranting further investigation.
- Full Text:
- Date Issued: 2016
Ericoid fungal inoculation of blueberry under commercial production in South Africa
- Bizabani, Christine, Fontenla, Sonia, Dames, Joanna F
- Authors: Bizabani, Christine , Fontenla, Sonia , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448610 , vital:74746 , https://doi.org/10.1016/j.scienta.2016.06.029
- Description: Ericoid mycorrhizal (ERM) fungi are known to enhance growth of plants belonging to the Ericaceae family. However, the outcomes of root-fungal associations in this family are influenced by several factors such as soil nutrient status, climatic conditions, host variety and fungal partner. The aim of this study was (i) to determine whether symbiotic fungal structures form in roots of Misty (Vaccinium corymbosum) and Brightwell (V. ashei) blueberry varieties, following inoculation with Leohumicola, Oidiodendron maius and Meliniomyces fungal species, and (ii) evaluate inoculation effects on the growth of blueberry varieties. The study was conducted for 60 weeks under commercial production conditions at Amathole Berries, Sutterheim, South Africa. All three fungi were isolated from Erica plants growing naturally in Albany Centre of Endemism of South Africa. All ERM formed mycorrhizal structures characteristic of typical ericoid colonisation in the roots of both Misty and Brightwell. However, percentage colonisation was low. The highest colonisation percentage, 20.4%, was observed in Misty inoculated with Oidiodendron maius. Colonisation was significantly different compared to un-inoculated controls in the Misty variety. In both varieties inoculated with either Leohumicola or Meliniomyces did not improve (p > 0.05) shoot growth and biomass. All fungal species improved root biomass in Misty but not in Brightwell. This indicates that ERM inoculation may potentially benefit plant of Misty and that responses to ERM inoculation vary between blueberry varieties.
- Full Text:
- Date Issued: 2016
- Authors: Bizabani, Christine , Fontenla, Sonia , Dames, Joanna F
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448610 , vital:74746 , https://doi.org/10.1016/j.scienta.2016.06.029
- Description: Ericoid mycorrhizal (ERM) fungi are known to enhance growth of plants belonging to the Ericaceae family. However, the outcomes of root-fungal associations in this family are influenced by several factors such as soil nutrient status, climatic conditions, host variety and fungal partner. The aim of this study was (i) to determine whether symbiotic fungal structures form in roots of Misty (Vaccinium corymbosum) and Brightwell (V. ashei) blueberry varieties, following inoculation with Leohumicola, Oidiodendron maius and Meliniomyces fungal species, and (ii) evaluate inoculation effects on the growth of blueberry varieties. The study was conducted for 60 weeks under commercial production conditions at Amathole Berries, Sutterheim, South Africa. All three fungi were isolated from Erica plants growing naturally in Albany Centre of Endemism of South Africa. All ERM formed mycorrhizal structures characteristic of typical ericoid colonisation in the roots of both Misty and Brightwell. However, percentage colonisation was low. The highest colonisation percentage, 20.4%, was observed in Misty inoculated with Oidiodendron maius. Colonisation was significantly different compared to un-inoculated controls in the Misty variety. In both varieties inoculated with either Leohumicola or Meliniomyces did not improve (p > 0.05) shoot growth and biomass. All fungal species improved root biomass in Misty but not in Brightwell. This indicates that ERM inoculation may potentially benefit plant of Misty and that responses to ERM inoculation vary between blueberry varieties.
- Full Text:
- Date Issued: 2016
Fungi and Lichens of the Limpopo Valley and Mapungubwe National Park
- Van der Walt, Retha, Dames, Joanna F, Hawley-McMaster, Greer
- Authors: Van der Walt, Retha , Dames, Joanna F , Hawley-McMaster, Greer
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/453434 , vital:75254 , ISBN 9780620904056
- Description: This is a 376 paged soft-cover book. With more than 1400 photographs for easy identification with disk included. With Maps, introduction glossary of terms and pictures. With descriptions and illustrations. Detailed introductory chapters for fungi and lichens sections. Information on more than 290 different local macro-fungi, lichen and slime mould species - including various novel spe-cies. Many of these may, however, occur widely in the rest of Africa and further afield. Chapters dealing with 15 different morphological groups. A succinct and descriptive text including information on the distinguishing features, ecology, distribution and edibility of species. English and Afrikaans common names. De-scription of families and genera. More than 1400 colour photographs (including a DVD) which allow detailed viewing as a further aid to identification. A detailed glossary of terms and picture glossary. A step-by-step guide to the collection of specimens. A map and background of the study area. Information on the early Mapungubwe civilization.
- Full Text:
- Date Issued: 2020
- Authors: Van der Walt, Retha , Dames, Joanna F , Hawley-McMaster, Greer
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/453434 , vital:75254 , ISBN 9780620904056
- Description: This is a 376 paged soft-cover book. With more than 1400 photographs for easy identification with disk included. With Maps, introduction glossary of terms and pictures. With descriptions and illustrations. Detailed introductory chapters for fungi and lichens sections. Information on more than 290 different local macro-fungi, lichen and slime mould species - including various novel spe-cies. Many of these may, however, occur widely in the rest of Africa and further afield. Chapters dealing with 15 different morphological groups. A succinct and descriptive text including information on the distinguishing features, ecology, distribution and edibility of species. English and Afrikaans common names. De-scription of families and genera. More than 1400 colour photographs (including a DVD) which allow detailed viewing as a further aid to identification. A detailed glossary of terms and picture glossary. A step-by-step guide to the collection of specimens. A map and background of the study area. Information on the early Mapungubwe civilization.
- Full Text:
- Date Issued: 2020
Genetic approaches to improve salinity tolerance in plants
- Kumar, Ashwani, Gupta, Aditi, Azooz, M M, Sharma, S, Ahmad, Parvaiz, Dames, Joanna F
- Authors: Kumar, Ashwani , Gupta, Aditi , Azooz, M M , Sharma, S , Ahmad, Parvaiz , Dames, Joanna F
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/453449 , vital:75255 , ISBN , https://doi.org/10.1007/978-1-4614-6108-1_4
- Description: Abiotic stress tolerance in plants is gaining importance day by day. Different techniques are being employed to develop salt tolerant plants that directly or indirectly combat global food problems. Advanced comprehension of stress signal perception and transduction of associated molecular networks is now possible with the development in functional genomics and high throughput sequencing. In plant stress tolerance various genes, proteins, transcription factors, DNA histone-modifying enzymes, and several metabolites are playing very important role in stress tolerance. Determination of genomes of Arabidopsis, Oryza sativa spp. japonica cv. Nipponbare and integration of omics approach has augmented our knowledge pertaining to salt tolerance mechanisms of plants in natural environments. Application of transcriptomics, metabolomics, bioinformatics, and high-through-put DNA sequencing has enabled active analyses of regulatory networks that control abiotic stress responses. To unravel and exploit the function of genes is a major challenge of the post genomic era. This chapter therefore reviews the effect of salt stress on plants and the mechanism of salinity tolerance along with contributory roles of QTL, microRNA, microarray and proteomics.
- Full Text:
- Date Issued: 2013
- Authors: Kumar, Ashwani , Gupta, Aditi , Azooz, M M , Sharma, S , Ahmad, Parvaiz , Dames, Joanna F
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/453449 , vital:75255 , ISBN , https://doi.org/10.1007/978-1-4614-6108-1_4
- Description: Abiotic stress tolerance in plants is gaining importance day by day. Different techniques are being employed to develop salt tolerant plants that directly or indirectly combat global food problems. Advanced comprehension of stress signal perception and transduction of associated molecular networks is now possible with the development in functional genomics and high throughput sequencing. In plant stress tolerance various genes, proteins, transcription factors, DNA histone-modifying enzymes, and several metabolites are playing very important role in stress tolerance. Determination of genomes of Arabidopsis, Oryza sativa spp. japonica cv. Nipponbare and integration of omics approach has augmented our knowledge pertaining to salt tolerance mechanisms of plants in natural environments. Application of transcriptomics, metabolomics, bioinformatics, and high-through-put DNA sequencing has enabled active analyses of regulatory networks that control abiotic stress responses. To unravel and exploit the function of genes is a major challenge of the post genomic era. This chapter therefore reviews the effect of salt stress on plants and the mechanism of salinity tolerance along with contributory roles of QTL, microRNA, microarray and proteomics.
- Full Text:
- Date Issued: 2013
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
Kalaharituber pfeilii and associated bacterial interactions
- Adeleke, Rasheed, Dames, Joanna F
- Authors: Adeleke, Rasheed , Dames, Joanna F
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440490 , vital:73787 , https://doi.org/10.1016/j.sajb.2013.10.003
- Description: Truffles are generally known to form a mycorrhizal relationship with plants. Kalaharituber pfeilii (Hennings) Trappe and Kagan-Zur is a species of desert truffle that is found in the southern part of Africa. The life cycle of this truffle has not been fully investigated as there are many unconfirmed plant species that have been suggested as potential hosts. Many mycorrhizal associations often involve other role players such as associated bacteria that may influence the establishment of the mycorrhizal formation and function. As part of an effort to understand the life cycle of K. pfeilii, laboratory experiments were conducted to investigate the role of ascocarp associated bacteria. Bacterial isolates obtained from the truffle ascocarps were subjected to microbiological and biochemical tests to determine their potentials as mycorrhizal helper bacteria. Tests conducted included stimulation of mycelial growth in vitro, indole acetic acid (IAA) production and phosphate solubilising. A total of 17 bacterial strains belonging to the Proteobacteria, Firmicutes and Actinobacteria were isolated from the truffle ascocarps and identified with sequence homology and phylogenetic methods. Three of these isolates showed potential to be helper bacteria in at least one of the media tested through the stimulation of mycelial growth. Furthermore, four isolates produced IAA and one was able to solubilise CaHPO3 in vitro. One isolate, identified as a relative of Paenibacillus sp. stimulated mycelial growth on all the media tested. Other bacterial isolates that showed potential stimulation of mycelial growth were identified molecularly as a Bacillus sp. and two strains of Rhizobium sp. This study has contributed to the existing knowledge on the biotic interactions with K. pfeilii which may be useful in further symbiont and re-synthesis investigations.
- Full Text:
- Date Issued: 2014
- Authors: Adeleke, Rasheed , Dames, Joanna F
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440490 , vital:73787 , https://doi.org/10.1016/j.sajb.2013.10.003
- Description: Truffles are generally known to form a mycorrhizal relationship with plants. Kalaharituber pfeilii (Hennings) Trappe and Kagan-Zur is a species of desert truffle that is found in the southern part of Africa. The life cycle of this truffle has not been fully investigated as there are many unconfirmed plant species that have been suggested as potential hosts. Many mycorrhizal associations often involve other role players such as associated bacteria that may influence the establishment of the mycorrhizal formation and function. As part of an effort to understand the life cycle of K. pfeilii, laboratory experiments were conducted to investigate the role of ascocarp associated bacteria. Bacterial isolates obtained from the truffle ascocarps were subjected to microbiological and biochemical tests to determine their potentials as mycorrhizal helper bacteria. Tests conducted included stimulation of mycelial growth in vitro, indole acetic acid (IAA) production and phosphate solubilising. A total of 17 bacterial strains belonging to the Proteobacteria, Firmicutes and Actinobacteria were isolated from the truffle ascocarps and identified with sequence homology and phylogenetic methods. Three of these isolates showed potential to be helper bacteria in at least one of the media tested through the stimulation of mycelial growth. Furthermore, four isolates produced IAA and one was able to solubilise CaHPO3 in vitro. One isolate, identified as a relative of Paenibacillus sp. stimulated mycelial growth on all the media tested. Other bacterial isolates that showed potential stimulation of mycelial growth were identified molecularly as a Bacillus sp. and two strains of Rhizobium sp. This study has contributed to the existing knowledge on the biotic interactions with K. pfeilii which may be useful in further symbiont and re-synthesis investigations.
- Full Text:
- Date Issued: 2014
Methods for assessing the quality of AM fungal bio-fertilizer: Retrospect and future directions
- Agnihotri, R, Sharma, M P, Bucking, H, Dames, Joanna F, Bagyaraj, D J
- Authors: Agnihotri, R , Sharma, M P , Bucking, H , Dames, Joanna F , Bagyaraj, D J
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448626 , vital:74747 , https://doi.org/10.1007/s11274-022-03288-3
- Description: In the recent past, the mass production of arbuscular mycorrhizal (AM) fungi has bloomed into a large biofertilizer industry. Due to their obligate symbiotic nature, these fungi are propagated on living roots in substrate-based pot cultures and RiTDNA in in vitro or root organ culture systems. The quality assessment of AM inocula remains critical for the production and efficacy evaluation of AM fungi. The vigour of AM inocula are assessed through microscopic methods such as inoculum potential, infectivity potential/infection units, most probable number (MPN) and spore density. These methods marginally depend on the researcher’s skill. The signature lipids specific to AM fungi, e.g. 16:1ω5cis ester-linked, phospholipid, and neutral lipid fatty acids provide more robustness and reproducibility. The quantitative real-time PCR of AM fungal taxa specific primers and probes analyzing gene copy number is also increasingly used. This article intends to sensitize AM fungal researchers and inoculum manufacturers to various methods of assessing the quality of AM inocula addressing their merits and demerits. This will help AM producers to fulfil the regulatory requirements ensuring the supply of high-quality AM inocula to end-users, and tap a new dimension of AM research in the commercial production of AM fungi and its application in sustainable plant production systems.
- Full Text:
- Date Issued: 2022
- Authors: Agnihotri, R , Sharma, M P , Bucking, H , Dames, Joanna F , Bagyaraj, D J
- Date: 2022
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448626 , vital:74747 , https://doi.org/10.1007/s11274-022-03288-3
- Description: In the recent past, the mass production of arbuscular mycorrhizal (AM) fungi has bloomed into a large biofertilizer industry. Due to their obligate symbiotic nature, these fungi are propagated on living roots in substrate-based pot cultures and RiTDNA in in vitro or root organ culture systems. The quality assessment of AM inocula remains critical for the production and efficacy evaluation of AM fungi. The vigour of AM inocula are assessed through microscopic methods such as inoculum potential, infectivity potential/infection units, most probable number (MPN) and spore density. These methods marginally depend on the researcher’s skill. The signature lipids specific to AM fungi, e.g. 16:1ω5cis ester-linked, phospholipid, and neutral lipid fatty acids provide more robustness and reproducibility. The quantitative real-time PCR of AM fungal taxa specific primers and probes analyzing gene copy number is also increasingly used. This article intends to sensitize AM fungal researchers and inoculum manufacturers to various methods of assessing the quality of AM inocula addressing their merits and demerits. This will help AM producers to fulfil the regulatory requirements ensuring the supply of high-quality AM inocula to end-users, and tap a new dimension of AM research in the commercial production of AM fungi and its application in sustainable plant production systems.
- Full Text:
- Date Issued: 2022
Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands
- Gokul, Jarishma K, Matcher, Gwynneth, Dames, Joanna F, Nkangala, Kuhle, Gordijn, Paul J, Barker, Nigel P
- Authors: Gokul, Jarishma K , Matcher, Gwynneth , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
- Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
- Full Text:
- Date Issued: 2023
- Authors: Gokul, Jarishma K , Matcher, Gwynneth , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
- Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
- Full Text:
- Date Issued: 2023