The diversity and the spread of alien invasive plant species in the Nylsvley Nature Reserve, Limpopo Province, South Africa

The diversity and the spread of alien invasive plant species in the Nylsvley Nature Reserve, Limpopo Province, South Africa

Abstracts (ATCC 10231) and clinical isolates: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. The dried leaves of Breonadia micr...

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Abstracts

(ATCC 10231) and clinical isolates: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans. The dried leaves of Breonadia microcephala, Colophospermum mopane, Commiphora pyracanthoides, Diplorrhyncus condylocaporn, Elaeodendron transvaalense, Elephantorrhiza elephantine, Eugenia natalitia, Leucaena leucocephala, Verninia corymbosa, Zanthoxylum humile, Ziziphus mucronataand and Ornithogalum ornithogaloides were extracted with acetone and water. The antifungal activity of the plant extracts was determined using the micro-dilution and bioautography methods, and their antioxidant activity was evaluated using a DPPH qualitative assay. The minimum inhibitory concentration (MIC) of 12 acetone plant extracts ranged from 0.04 to 1.25 mg/ml while those of aqueous extracts had a very weak antifungal activity against the test microorganisms which varied from 0.63 to more than 2.5 mg/ml. Acetone extracts of C. mopane and D. condylocapron were the most active with an MIC value of 0.04 mg/ml against C. albicans (ATCC 10231), A. fumigatus and C. neoformans. C. mopane also had the the highest total activity of 7468 ml/g against these microorganisms. This means that the acetone extract from 1 g of the dry plant material could be diluted to 7468 ml and still kill the test microorganisms. With regard to bioautography, the poorly separated compounds in the aqueous plant extracts had no activity. However, some bands in acetone extracts of B. microcephala, C. mopane, E. natalitia and V. corymbosa had less visible zones of inhibition against C. neoformans at an Rf value of 0.9. The activity of the compounds was not intense enough to consider the isolation and characterization of the antifungal compounds. However, the HPLC and TLC chemical profiles of the plant extracts were recorded and serve as basic reference for all future investigations. Acetone plant extracts also showed several bands with varying degrees of antioxidant activities while aqueous extracts hardly showed the antioxidant activities. The antifungal activity exhibited by the plant extracts supports their traditional use to some extent. doi:10.1016/j.sajb.2015.03.164

The effects of stratification on Vangueria infausta Burch seeds M. Mutele, P.W. Mokwala Department of Biodiversity, School of Molecular and Life Sciences, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa The velvet wild-medlar (Vangueria infausta Burch) is an indigenous fruit tree. Each fruit has three to four seeds. The seeds have a hard endocarp like those of the stone fruits. The latter require stratification at a low temperature for germination. An investigation was carried out on the effects of stratification at 6 °C on the germination of the velvet wild-medlar seeds. The seeds were collected from the wild under the trees. The highest germination percentage of 40% was obtained from non-stratified seeds with the lowest germination percentage of 6.7% obtained from seeds stratified for both three and four weeks. However, seeds stratified for five weeks showed a higher germination percentage of 23.3%. Anatomically, there were no observable differences among the treatments. In some seeds there were globules that coalesced to form huge ones. These were probably non-viable seeds that would not germinate. doi:10.1016/j.sajb.2015.03.165

Ethnobotanical survey of medicinal plants prescribed by traditional healers for the treatment of chest and coughing related diseases in the Eastern Cape Y. Ndamanea, L. Kambizib, S.P. Songcac a Department of Botany, Walter Sisulu University, Private Bag X1, Mthatha 5099, Eastern Cape, South Africa

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Department of Horticulture, Cape Peninsula University of Technology, PO Box 652, Cape Town 8000, Western Cape, South Africa c Faculty of Science, Engineering and Technology, Walter Sisulu University, PO Box 19712, Tecoma, East London 5214, Eastern Cape, South Africa Medicinal plants have been used all over the world as unique sources of medicines serving as either primary sources or secondary sources of drugs. It is estimated that about 25% of prescription drugs and 11% of drugs that are considered essential by the WHO are derivatives of plants and a large number of synthetic drugs are obtained from plants as precursor compounds. The documentation of the traditional medicinal plants could contribute to the conservation, sustainable management and use of plant resources. About 80% of the people in developing countries still depend on local medicinal plants to fulfill their primary health care needs. The factors that lead to more people relying on medicinal plants for their primary health care needs are absence or inaccessibility of modern healthcare services and high prices of pharmaceutical products. This study was aimed at documenting and analyzing information on medicinal plants used to alleviate coughing and chest related ailments in the OR Tambo district municipality of Eastern Cape. It was imperative to carry out an ethnobotanical survey to identify different plants used to treat these diseases. Data collection was archived through participatory appraisal research with traditional healers and knowledgeable elders who practice herbal medicine in the study area. Various ethnobotanical techniques were used to collect data including semi-structured interviews, field observations and group discussions. A total of 17 plant species were reported (13 from the wild, 2 from home gardens and 5 species occurring in both the wild and home gardens, belonging to 12 families). The most frequently harvested plant parts were leaves and roots, followed by stems and bark. About 80% of the remedies were prepared from single plants with the highest proportion prepared by crushing, pounding and mixing in water. The most widely used method of application was internal scoring in which oral application was the main route of administration. Medicinal plants reported to be the most widely and frequently used by the local people as remedies for coughing and chest related diseases are Tetradenia riparia, Plectranthus laxiflorus and Eucalyptus regnans.

doi:10.1016/j.sajb.2015.03.166

The diversity and the spread of alien invasive plant species in the Nylsvley Nature Reserve, Limpopo Province, South Africa E. Nenzhelele, M.P. Tshisikhawe Department of Botany, School of Mathematical and Natural sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa Invasive alien plant species have been identified as the second main cause of biodiversity loss after habitat destruction and the main cause of species extinctions in island ecosystems. A total of 30 quadrats which were 10 m × 10 m in size were constructed subjectively on areas where alien invasive species were identified. Both alien invasive plants and indigenous plants within the quadrats were sampled. Sida spinosa (Malvaceae family) was found to have the highest frequency of 80% followed by Hibiscus cannabinus (Malvaceae family) with a frequency of 53.33% and the least with the lowest frequency was Helichrysum kraussii (Asteraceae family) having a frequency of 3.33%. The invasive alien plant species were found dominating throughout the study area whereas indigenous plant species were found to be very low. Inverse J-shaped relationships between the indigenous and the invasive alien plant species were observed, with alien invasive plant species dominating the pattern of distribution over indigenous

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ones. Special attention therefore needs to be given to invasive alien plant species before they can lead to the extinction of native plants species. doi:10.1016/j.sajb.2015.03.167

Diseases and pests of Encephalartos species in South Africa R. Nesamari, T.A. Coutinho, J. Roux Department of Microbiology and Plant Pathology, DST & NRF Centre of Excellence in Tree Health Biotechnology (CTHB), University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa

areas amongst the study area where the height, diameter and distance between species were measured. The results obtained show that P. alba has great effects on the growth of native grass, as there were differences between populations inside the patch and away from the patch. P. alba can co-exist as there are some grass species inside its population but it affects the growth of grass species as their height is different with that of the species outside the population. doi:10.1016/j.sajb.2015.03.169

Antifungal activity of the selected medicinal plants used to treat candidiasis

The cycad genus, Encephalartos, is endemic to Africa with more than half of its species occurring in South Africa. Seventy-three percent of South African Encephalartos species are threatened with extinction with four species already extinct in the wild. The major threat to Encephalartos species in South Africa is the illegal trade of cycads. In addition, biotic factors, such as insect pests and microbial diseases that affect these plants, are on the increase. The aim of this study was to identify diseases and insect pests of Encephalartos species in South Africa. Symptomatic plant material and insects were collected from diseased cycad species in the KwaZulu-Natal, Limpopo and Gauteng provinces. Microbial isolates obtained were identified based on morphology and DNA sequence data. Species of Alternaria, Phoma and Pseudocercospora were often isolated from leaf spots and Bionectria and Fusarium species from dying cycads. The plant pathogen, Phytophthora cinnamomi, was isolated from dying Encephalartos tranvenosus plants in the Modjadji cycad reserve in Limpopo. Insect pests observed causing the most damage to cultivated cycads were the beetle, Amorphocerus talpa, and the scale insect, Aspidiotus capensis. A. talpa was observed infesting cycad cones in the Pretoria Botanical Gardens, causing discolouration and death of the cones. The scale insect, A. capensis, was found on the leaflets of many cycads, causing chlorosis and premature death of leaves. In this study we also report, for the first time, the scale insect, Aulacaspis yasumatsui, infesting cycads in South Africa. A. yasumatsui was identified based on morphology and DNA sequence data. Plants infested by this scale insect showed symptoms of severe leaf chlorosis and necrosis. The presence of A. yasumatsui on South African Encephalartos species is of much concern and efforts should be made to manage this pest in the country.

The aim of the study was to investigate the antifungal activities of the selected plants used traditionally for the treatment of candidiasis. Leaves of five plant species (Ehretia rigida, Ximenia americana, Anthocleista grandiflora, Artabotry branchypetalus and Sarcostemma viminale) were extracted with distilled water and acetone. The latter were tested against six isolates of Candida species (Candida albicans, Candida parapsilosis, Candida glabrata, Candida tropicalis, Candida krusei and Cryptococcus neoformans). The antifungal activity was conducted using microdilution method. Clotrimazole and acetone were used as positive and negative controls respectively. The plant extracts were tested for the antioxidant activity using DPPH qualitative assay. Acetone extracts of A. grandiflora, X. americana and A. branchypetalus were moderatively active with MIC values ranging from 0.31 mg/ml to 0.63 mg/ml. Aqueous plant extracts had very weak activity against the test organisms with MIC values ranging from 0.63 mg/ml to 1.25 mg/ml. Acetone plant extracts inhibited the growth of the Candida species better than aqueous plant extracts. Minimum inhibitory concentrations (MIC) of the positive control (Clotrimazole) against the test organisms ranged from 0.04 to 0.08 mg/ml. Acetone plant extracts also showed high antioxidant activity than the aqueous plant extracts. The results of this study showed that some of the selected medicinal plants can be potential sources of antifungal agents and validate their use in the traditional medicine to some extent.

doi:10.1016/j.sajb.2015.03.168

doi:10.1016/j.sajb.2015.03.170

The interaction and co-existence of alien plant species Populus alba L. with native grass species

Assessment of potential invasiveness of Verbascum thapsus L. in South Africa

P.N. Nesengani, M.H. Ligavha-Mbelengwa Deparment of Botany, School of Mathematical and Natural Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa

Z. Ntantiso, T.P. Jaca Invasive Species Programme, South African National Biodiversity Institute, Private Bag X101, Pretoria 0001, South Africa

Populus alba is a tree species which is a fast grower that is distributed naturally on the bank of rivers in arid, and semi-arid regions and it is naturally found on a variety of soil types, being tolerant to pollution. It is geographically extended mainly in Asia and Africa. Populus alba is a member of the willow family (Salicaceae) that is native to Eurasia. The main objective of the study was to have clear understanding on how P. alba may affect or benefit the indigenous grass species. The study was conducted on a study site along the N1 south road where there were two patches of P. alba species, one on the left right hand side of the road N1 south and the one on the left. The Quadrat method was used to sample different

K.V. Nkuna, N.A. Masevhe School of Maths and Natural Sciences, Department of Botany, University of Venda, Private Bag X5050, Thohoyandou, South Africa

Verbascum thapsus (common mullein) is a hairy biennial herb with rosette leaves in the first year. It is native to Europe and naturalized in temperate areas of the world, including North America, Hawai'i, Australia, and New Zealand. The plant spreads through production of numerous seeds (up to 180,000) per plant, which are produced during the second year of growth. In South Africa, V. thapsus was first observed naturalised in Gauteng Province at Rietfontein, Bronberg Conservancy and has since been recorded in areas around northern Free State and Northern Cape Province. The species is not yet listed as invasive in the country; it is listed as a suspect candidate that needs evaluation. The aim of this study was to assess the invasiveness of V. thapsus in South Africa. Australian/New