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Volume 5 Number 1 2011
CONTENTS AND ABSTRACTS
Tariro A. Chitemerere, Stanley Mukanganyama (Zimbabwe) In Vitro Antibacterial Activity of Selected Medicinal Plants from Zimbabwe (pp 1-7)
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ABSTRACT
Original Research Paper: This study sought to give a scientific basis to plants already used for traditional purposes and also probe new antibacterial constituents from randomly selected plants whose anti-infective properties have not been evaluated. The antibacterial activity of ethanolic extracts from 19 Zimbabwean plants was assessed using the agar diffusion assay, minimum inhibitory concentration and minimum bactericidal using ampicillin as reference. Accumulation of rhodamine 6G in bacteria was used to determine the activity of extracts as drug efflux pump inhibitors (EPIs). Test bacteria were Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus cereus and Bacillus subtilis. At least 8 extracts exhibited antibacterial activity against all bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination of plant extracts ranged from 0.05 to 0.5 mg/ml and 0.06 mg/ml to > 1 mg/ml, respectively. Mangifera indica, Callistemon citrinus and Vernonia adoensis were bactericidal for all bacteria while the other extracts were bacteriostatic, and were thus the most potent. These 3 extracts were effective EPIs in the uptake of R6G with activity greater than the standard inhibitor reserpine. Hence, the compounds in these plants can serve as templates for the development of new antibacterial agents as well as efflux pump inhibitors.
Rumbidzai Mangoyi, Stanley Mukanganyama (Zimbabwe) In Vitro Antifungal Activities of Selected Medicinal Plants from Zimbabwe against Candida albicans and Candida krusei (pp 8-14)
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Original Research Paper: Thirty-eight Zimbabwean medicinal plant extracts were investigated for in vitro antifungal activity against Candida albicans and Candida krusei. These plants are used for the traditional treatment of various ailments, including fungal infections. The ethanol extracts were tested for antifungal activity using the agar disc diffusion method. The minimum inhibition concentrations (MICs) were determined for plant extracts that showed high efficacy against the tested microorganisms using the broth dilution method. The minimum fungicidal concentration (MFC) assay was carried out to determine if the fungal growth could irreversibly be inhibited by these plant extracts. The ciprofloxacin accumulation assay was carried out to investigate if these plant extracts could inhibit the activity of active drug efflux pumps in both Candida species. Nineteen plant extracts, among the 38 investigated, showed significant antifungal activity. MIC values ranged from 0.08–0.63 mg/ml for both C. albicans and C. krusei. MFCs ranged from 0.31–2.5 mg/ml. Combretum zeyheri extract had the highest antifungal activity in all cases. Combretum zeyheri and Combretum molle extracts were the most potent drug efflux pump inhibitors. The extracts from these Combretum species showed the greatest antifungal activity by both inhibition of growth and inhibition of drug efflux in C. albicans and C. krusei. Combretum molle and Combretum zeyheri provide a phytopharmacological basis for the traditional use of plant extracts against fungal infections.
Oluduro Anthonia Olufunke (Nigeria) Antibacterial Activities of Allium sativum, Momordica charantia and Zingiber officinale on Food- and Water-Borne Pathogens (pp 15-19)
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Original Research Paper: The antibacterial activity and phytochemicals of the aqueous, ethanolic and methanolic extracts of Momordica charantia, Zingiber officinale and Allium sativum used traditionally for the treatment of certain food- and water-borne diseases in South Western part of Nigeria was studied. The inhibitory effect of the plant extracts was investigated in vitro against clinical isolates of Esherichia coli, Salmonella typhi, Shigella dysenteriae, Staphylococcus aureus, Klebsiella pneumoniae,and Bacillus cereus. Momordica charantia and A. sativum showed an inhibitory effect at 20 to 50 mg/ml. The highest zone of growth inhibition of 11.0 mm each was recorded with methanolic extract of A. sativum and ethanolic extract of M. charantia against S. aureus at50 mg/ml. There was no significant inhibitory effect produced with the extract of Z. officinale. The minimum inhibitory concentration of methanol extracts of M. charantia and A. sativum on all test organisms was 0.01 and 0.0001 mg/ml, respectively. Phytochemistry of the plant extracts revealed the presence of one or more of the following components: alkaloids, tannin, flavonoids, and saponin. The study showed that only the extracts of M. charantia and A. sativum showed significant antimicrobial activity against the test organisms at above 20 mg/ml and the activity compared favourably with the standard antibiotics-amoxicillin and ciprofloxacin used in the study. The findings therefore, justify the folkloric use of these plants in the treatment of certain ailments of microbial origin, most especially those caused by water- and food-borne pathogens.
Daniel Dompreh (UK/Ghana), Michael D. Swaine (UK), George Odamtten (UK/Ghana) Stigma and Stand Specificity in Fusarium verticilloides Associated with Talbotiella gentii (pp 20-25)
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Original Research Paper: Pathogens, mainly fungus, were after fruit set, the most common cause of fruit abortion in Talbotiella. The measurement of stigmatic pollen load demonstrates that there is no shortage in the quantity of pollen flow within Talbotiella populations. However, germination of pollen grains on stigmatic surface of the species and growth of pollen tube down the style to fertilize ovules are inhibited by fungal hyphae. Air sampling at 3 populations of Talbotiella using 3 agar media was carried out to find out the prevalence of fungi. A total of 26 fungal species belonging to 17 genera was observed. The genera Aspergillus, Penicillium and Cladosporium recorded highest number of species. Penicillium aurantiogriseum and Fusarium verticilloides were the dominant species within Talbotiella populations. Fusarium verticilloides was found to mainly occupy the stigmatic surface of the Talbotiella species.
Hajer Regaieg, Najet Horrigue-Raouani, Mejda Daami-Remadi (Tunisia) Isolation of Non-pathogenic Fusarium spp. Strainsfor Biological Control of Meloidogyne incognita on Tomato (pp 26-29)
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Original Research Paper: This study was conducted to investigate the effects of three isolates of Fusarium spp. (HR4, HR23 and HR57) on Meloidogyne incognita (Kofoid and White), and their pathogenicity on tomato (Lycopersicon esculentum Mill.) plants. Fusarium isolates were obtained from egg masses extracted from tomato plants grown in plastic greenhouses in Békalta (centre of Tunisia) and identified by sequencing of the internal transcribed spacer fragments (ITS). Healthy M. incognita eggs were placed on fungal colonies already formed on water agar. The highest infection rate was observed 7 days after inoculation and reached 70%. F. oxysporum had the ability to penetrate through the eggshell. The effects of Fusarium spp. on M. incognita in tomato plants were tested in pot experiments in growth chambers. A positive effect was observed on plant height fresh shoot and root weight. The number of galls and egg masses in the root system decreased within 45 days after inoculation of Fusarium spp. strains.
Mohamed Elimem, Ahlem Harbi, Brahim Chermiti (Tunisia) Populations of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) in a Greenhouse Pepper Crop in the Region of Moknine (Tunisia) in Relation to Environmental Conditions (pp 30-34)
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Original Research Paper: Populations of Frankliniella occidentalis were monitored in a greenhouse pepper crop in the region of Moknine (Governorate of Monastir, Center-east of Tunisia) in 2009 using blue sticky traps and weekly flower samples. Critical periods of pest proliferation were correlated with greenhouse conditions of temperature, photoperiod and relative humidity. During the cold season and beginning of spring, populations showed limited variation, with the number of trapped thrips more or less constant. At this period, low temperatures, high relative humidity and shorter day-length prevent thrips development. Thrips populations increased during April, May and early June. This coincided with an increase in temperature, slight decrease in relative humidity, and longer days, and led to high population levels of F. occidentalis.
Eman El-Sayed, Sherin Mahfouze, Assam Shaltout, Khalid El-Dougdoug, Ramadan Sayed (Egypt) Mutation Breeding of Banana cv. ‘Grand-Nain’ for Resistance to Some Banana Viruses Using Biotechnology and Physical Mutagens (pp 35-40)
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Original Research Paper: Banana is one of the most important fruit crops in Egypt both for domestic and export markets. At present, the industry is beset with low productivity due to Banana bunchy top virus (BBTV) and Banana mosaic virus (BMV). Banana cultivars are not appropriate for sexual breeding because both male and female are sterile. Thus, BBTV and BMV resistance cannot be incorporated into the banana by conventional breeding. Use of biotechnology techniques combined with mutagenesis using physical mutagens in Musa spp. allows genetic variability to be increased to improve important agronomic characters. The objective of this study was to develop mutant clones of Musa cv. ‘Grand-Nain’ with reduced height, good agronomical traits and resistance to both of BBTV and BMV viruses. Multiple buds obtained by in vitro culture were subjected to gamma radiation from 60Co sources at 20, 40 and 60 Gy. Irradiated buds were multiplied, elongated, rooted, hardened and acclimatized in the glasshouse and were transplanted to the field. The selection of mutant plants is based on morphological and ISSR-PCR markers. DNA-based markers were reliable and reproducible for mutant selection of BBTV- and BMV-resistant banana plants used in this study. Field screening was carried out against two different isolates of BBTV andBMV using a syringe method of inoculation. Only three banana plants treated with 60 Gy were resistant to the BMV isolate. No BBTV-resistant banana plants were obtained.
Nadia Gad, Fatma H. Abd el Zaher, H. K. Abd El Maksoud, M. R. Abd El-Moez (Egypt) Response of Faba Bean (Vicia faba L.) to Cobalt Amendments and Nitrogen Fertilization (pp 41-45)
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Original Research Paper: Two field experiments were conducted in the winter growing season in 2008 and 2009 on faba bean (Vicia faba L. var. ‘Nubaria 3’) at Nubaria Agricultural Station, National Research Center to evaluate the plant response to cobalt amendments at different rates of N fertilization. Prior to that, a preliminary greenhouse pot experiment was conducted in 3 replicates on the same plant and NRC farm soil within the year of 2007 to define the more promotive concentration of cobalt between 10 concentrations, started from 2, 4, 8, 12, 16, and 20 mg/L cobalt. The plants left to grow until 60 days-old and then removed for measurement of some plant parameters and chemical analysis. The amendment of cobalt to the soil improved the growth parameters of the faba bean plants inoculated with Rhizobium leguminosarum var. vicia bacteria compared to the cobalt untreated plants (control). Values of plant height, leaves number and area, shoot dry weight, root dry weight as well as nodules number and weight, seed yield, nitrogenase activity and plant mineral content were gradually increased by the successive increase in cobalt dose from 0 to 12 ppm. At the highest dose of cobalt (16 ppm), these values tended to decrease. The data clearly exhibited also that all yield measurements at all N doses were scanty and uneconomically in absence of cobalt amendment, particularly at the low doses of N fertilization. It could be concluded that cobalt is an essential element for certain microorganisms, particularly those fixing atmospheric nitrogen in particular, for nodules formation, its deficiency seems to depress the efficiency of N2 fixation process.
Alaba T. Fariyike, Oyeboade S. Adebayo, Gbenga S. Akinwumi, Olufemi T. Ademoyegun, Catherine A. Akinpelu, Esther A. Adesegun (Nigeria) Evaluation of Growth and Yield of (Capsicum annum L.) var ‘Nsukka Yellow’ under Different Fertilizer Regimes in Ibadan, South-western Nigeria (pp 46-49)
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Original Research Paper: Capsicum annum L.) var ‘Nsukka Yellow’is a spice crop in high demand and which commands a high price in the South Eastern parts of Nigeria because of its bright yellow colour and aroma which distinguishes it from other pepper varieties. The production of this spice crop should not be restricted to this region alone; it should be extended to other parts of the country with the use of adequate fertilizer. Therefore, a field trial was conducted at the National Horticultural Research Institute, Ibadan, South Western Nigeria to assess the growth and yield of this pepper under different fertilizer regimes. The experiment was laid out in a randomized complete block design with four replications. Treatments used were control (no NPK or poultry manure), 15 t/ha poultry manure, 30 t/ha poultry manure, 45 kg/ha NPK 15: 15: 15, 90 kg/ha NPK 15: 15: 15 and 15 t/ha poultry manure + 45 kg/ha NPK 15: 15: 15. Data were collected at two-week intervals. Results showed that the combination of poultry manure and NPK fertilizers (15 t/ha + 45 kg/ha) was the best in terms of plant height, number of leaves, stem girth, main branch and yield compared to the control. Yield was significantly (P < 0.05) influenced by different fertilizer regimes. A yield of 14.2, 11.4, 10.9, 9.1, 7.7 and 3.4 t/ha was obtained in combined fertilizer, 90 kg/ha NPK 15: 15: 15, 45 kg/ha NPK 15: 15: 15, 30 t/ha poultry manure, 15 t/ha poultry manure, and the control respectively.
Tchoa Koné, Mongomaké Koné (Côte d’Ivoire), Jaime A. Teixeira da Silva (Japan), Daouda Koné, Yatty Justin Kouadio (Côte d’Ivoire) Effect of Substrate Type and Bulb Size on in Vivo Production ofSeedlings in Three Cultivars of Plantain (Musa spp.) (pp 50-55)
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Original Research Paper: The expansion and improvement of plantain are limited by the lack of clean planting material free of pests and diseases. Several techniques have been developed to increase seed production. These techniques require a longer time to generate and they are laborious, carry vector diseases and sometimes, are too expensive for farmers. The present study aims to evaluate the effects of substrate type and bulb size on the production of healthy vivo plantain plants. The use of Furadan-Mancozeb significantly reduced the contamination rate. On average, the time necessary to observe the first appearance of buds was 24 days with small bulbs (weight < 150 g) and 14 days for large bulbs (weight > 600 g), independent of the cultivar. The number of buds produced varied with the cultivar, the substrate type and bulb size. In cv. ‘Orishele’, bulbs with sizes ranging from 450 to 600 g developed more buds (17.67) on sawdust. With cv. ‘Corne 1’ and ‘French 2’, forest soil was the best substrate (28.69 and 36.64 buds, respectively) with bulb size varying between 300 and 450 g. The time necessary for seed production ranged between 63 and 90 days.
Felix D. Ugese, Paul K. Baiyeri, Benjamin N. Mbah (Nigeria) Nursery Media Influences Growth of Seedlings of the Shea Nut Tree (Vitellaria paradoxa C. F. Gaertn.) (pp 56-59)
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Original Research Paper: Four nursery media comprising a soil-based (SB) medium and three rice hull-based (RHB) media, formulated on a volume basis were used to grow seeds of shea butter tree (Vitellaria paradoxa) obtained from three sources: Makurdi, Jalingo and Kano, in Nigeria. The specific media were topsoil: poultry manure: river sand (1: 2: 3); rice hull: poultry manure: river sand (1: 2: 3); rice hull: poultry manure: river sand (1: 3: 2) and rice hull: poultry manure: river sand (2: 3: 1). Factorial combinations of the four media and three accessions were laid out in a completely randomised design (CRD) replicated three times. Analysis of variance results indicated significant effect of accession on leaf area and all dry matter traits except shoot dry matter content. Growth media also exerted significant influence on all seedling growth and dry matter attributes except plant height and number of leaves. Interaction between accession and growth media significantly influenced all the traits measured. It was evident that across all accessions, the growth medium 1: 2: 3 (RHB), gave better values of seedling growth, dry matter yield and distribution of Vitellaria seedlings while results from the control medium were, in most cases, inferior. Generally, dry matter partitioned to the roots varied between 58.3 and 80.0%.
Amel Kerkeni, Najet Raouani, Mohamed Ben Khedher (Tunisia) Suppression of the Root-knot Nematode Meloidogyne incognita on Tomato by Composted Animal Manures (pp 60-62)
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Short Communication: The efficacy of five animal manure composts (C1, C2, C3, C4 and C5) as substrate amendments for control of root-knot nematode Meloidogyne incognita on tomato was studied. Results showed that plants in substrates amended with 25% of the different composts had lower number of M. incognita in the roots than those grown in unamended control substrate (perlite). Compared to untreated control, all treatments decreased significantly (P < 0.05) the galling index with the effect being more pronounced with 25% of compost C4 (40% cattle manure (CM) + 40% sheep manure (SM) + 20% crop residues) and compost C1 (50% CM + 25% SM +25% poultry manure). Moreover, improvement of plant growth parameters as a consequence of suppression of M. incognita was observed in the inoculated plants.
Sola Ogunyemi, A. Foluke Odewole (Nigeria) Effect of Neem (Azadirachta indica A. Juss) on Seed Germination of Senna sophera L. Roxb and Crotalaria ochroleuca G. Don. (pp 63-65)
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Short Communication: Azadirachta indica A. Juss leaf litter and root extract were evaluated for its allelopathic activity against Senna sophera L. Roxb and Crotalaria ochroleuca G.Don seeds in the Laboratory and Screen House of the Department of Crop Protection and Environmental Biology, University of Ibadan Ibadan, Nigeria. C. ochroleuca germination was not significantly (P < 0.05) affected by neem leaf litter and root extract. Extract of leaf litter and root significantly lowered S. sophera germination at early days of planting. The results from the screen house experiment showed that there were no conspicuous negative effect on the germination and seedling growth of both seeds when compared with the control.
Idowu Agida Oladayo Oluwakemi, Nwanguma Ephraim Ifeahyi, Ademoyegun Olufemi Temitope (Nigeria) Seasonal Variations in Capsaicin Content, Vitamin C and Carpometric Characteristics of Long Cayenne Pepper Accessions from South-Western Nigeria (pp 66-69)
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Short Communication: Accessions of long cayenne peppers were obtained from different locations in south-western Nigeria. The seeds were processed and planted in an experimental plot at two major seasons (rainy and dry season) to evaluate the effect of seasonal variation in the level of capsaicin content, vitamin C and carpometric properties in its fruits. Capsaicin, which is responsible for the sensation of pungency or heat in pepper, varied with a mean of 2.98 ± 0.34 and 3.31 ± 0.48 mg/g dry weight (DW), ascorbic acid of 20.14 ± 6.67 and 31.01 ± 15.80 mg/100 g FW, pH of 5.06 ± 0.20 and 5.09 ± 0.16, total soluble solid of 5.55 ± 0.98 and 9.59 ± 0.80% and ash contents of 1.11 ± 0.26 and 1.15 ± 0.21% for the rainy (25 of April – November, 2008) and dry (7 August, 2008 – March, 2009) seasons, respectively. There were significant differences in the level of ascorbic acid, total soluble solid (°Brix) and capsaicin, but not for pH and ash contents (P > 0.05). This study indicates that capsaicin, ascorbic acid and total soluble solid can vary considerably with changes in planting season as a result of environmental conditions.
Vincent I. Ibekwe, Ethelbert U. Ezeji (Nigeria) Antimicrobial Activity of Leaf and Root Extracts of Parkia biglobosa (African Locust Bean) (pp 70-72)
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Research Note: The study of antimicrobial properties of aqueous and ethanol extracts of leaves and roots of Parkia biglobosa (African locust bean) was carried out using disc paper impregnation and gel diffusion techniques. The ethanol extracts of both the leaves and roots showed inhibitory activity on all the test organisms. The minimum inhibitory concentration (MIC) of the root extract showed inhibitory activity to be most pronounced on E. coli followed by Proteus mirabilis, Pseudomonassp., Klebsiella sp., Staphylococcus sp., Streptococcus aureus and Bacillus sp. The MIC of the leaf extract, on the other hand, showed inhibitory activity to be most pronounced on E. coli followed by Proteus mirabilis and least against Staphylococcus sp., and Streptococcus aureus. However, the minimum bacterial concentration (MBC) of the extracts with different dilutions was found to be bacteriostatic for all the test organisms used in the study. The water extracts of all plant parts showed no appreciable antibacterial activity towards any of the bacteria tested. The findings from this study corroborate the use of P. biglobosa for medicinal purposes by herbal healers. |
