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Influence of the Metabolites of three Paecilomyces Species on the Germination and Seedling Development of two Ghanaian Maize Varieties (Abeleehi and Obaatanpa)
(University of Ghana, 199-10) Minamor, A.A.; Odamtten, G.T.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Botany
The mycoflora of two recently-developed maize (Zea mays L) varieties Abeleehi and Obaatanpa have been studied under varying ambient equilibrium relative humidities ERH’s (55, 60, 65, 70, 75, 80, 85, 90 and 95%) representative of the Ghanaian ambient conditions. The potential pathogenicity of selected contaminating fungal species (A. alutaceus, = A. ochraceus, Fusarium, moniliforme, Penicillium digitatum, Peacilomyces carneus, P. puntoni and P. varioti) was also tested under laboratory, field and greenhouse conditions. Finally, the fungal succession or phenology of the species encountered in the rhizosphere and non-rhizosphere soil containing treated maize grains (Abeleehi and Obaatanpa varieties) treated with conidia/mycelium or culture filtrate of the three Paecilomyces species (P. carneus, P. puntoni and P. varioti) was studied. About thirty (30) and twenty-eight (28) species of fungi belonging to the genera Aspergillus, Penicillium, Curvularia, Chaetomium, Cladosporium, Emericella, Eurotium, Fusarium, Paecilomyces, Mucor, Neurospora and Rhizopus were isolated from Abeleehi and Obaatanpa varieties respectively at ERH’s 55-95%. Aspergillus species {Aspergillus candidus, A. effusus, A. fumigatus, A. giganteus, A. niger, A. ochraceus, (= A. alutaceus), A. sulphureus, A. tamarii, A. ustus, A. versicolor, A. wentii and Aspergillus sp) predominated over the others followed by Penicillium (Penicillium brevi-compactum P. critinum, P. verrucosum, P. digitatum, P. expansum, P. funiculosum, P. glabrum and P. nigricans). Fungi belonging to the other genera encountered were Curvularia, Paecilomyces, Chaetomium, Cladosporium, Emericella, Eurotium, Fusarium, Mucor. The species diversity was influenced by grain variety and the ERH at which the grains were stored. Aspergillus flavus was ubiquitous and was encountered in all grains stored at 55-95% ERH. Fusarium monilifonne was isolated from some grains incubated at 65-95% ERH. Xerophilic or xerotolerant fungal species like Aspergillus fumigatus, A. alutaceus ( = A. ochraceus), A. gigunteus, Paecilomyces carneus, P. puntoni and P. varioti were isolated at 55-65% ERH in both grain varieties. The best vegetative growth (radial) of selected species was influenced by both the medium and temperature of incubation. Paecilomyces carneus grew best at 30°C, P. puntoni at 30-35°C and P. varioti at 30°C. All the Paecilomyces species, however, could grow well at 40°C. Aspergillus species tested (A. flavus, A. giganteus, A. alutaceus) grew best at 30°C and remained depressed in growth at 40°C; so did Penicillium digitatum and Fusarium moniliforme. The three Paecilomyces species produced their toxic metabolites in 2 days and their undiluted culture filtrates depressed seed germination of ’Abeleehi’ and ’Obaatanpa’ by 10-75% (depending on fungal species and period of incubation). This inhibitory effect was gradually removed with increasing dilution (up to 1:10v/v). There were varietal differences in the response of the germinating grains to the toxic metabolites of P. carneus, P. puntoni, and P. varioti. Undiluted culture filtrate of the listed three Paecilomyces species also severely depressed length of the emerging radicles of ‘Abeleehi’ and ‘Obaatanpa’ by 45-90% but this inhibition was gradually removed by increasing dilution of the culture filtrates (up to 1:10V/V dilution). The inhibition of seed germination and radicle development by culture filtrate of the three Paecilomyces species was not confined to maize only as their adverse effect on seed germination and radicle development was reproduced in vitro using tomato (Lycopersicon esculentum Mill var. Owusu-Bio and Wosowoso) and pepper (Capsicum annuum L). In this instance, the inhibitory principle was still potent even at 1:10V/V dilution level. Culture filtrate of Aspergillus alutaceus ( = A. ochraceus) at the highest concentration depressed seed germination of Abeleehi and Obaatanpa varieties by 50-70% and reduced radicle length by 60-90%. The inhibitory effect was gradually removed by increasing dilution (up to l:10v/v). Similarly, F. moniliforme and P. digitatum had the same deleterious effect on germination and radicle development of ’Abeleehi’ and ’Obaatanpa’ maize varieties. Seed germination was depressed 50-70% and radicle length by 40-90% when the undiluted culture filtrate of F. moniliforme and P. digitatum were applied to the grains. In all instances, the inhibitory effect was gradually removed by increasing dilution o f the culture filtrates. There were varietal differences between the three Paecilomyces species in their effect on vegetative growth and dry matter accumulation of Abeleehi and Obaatanpa maize varieties. Metabolites of P. carneus, P. puntoni and P. varioti variably depressed plant height, leaf width, leaf length, dry matter accumulation, (dry weight of root and shoot systems) as well as chlorophyll a and b contents of Abeleehi and Obaatanpa varieties cultivated in the field and under green house conditions. The maize cobs obtained from the field plants infected with Paecilomyces species were diminutive with fewer and smaller grains in the cob as compared to the control. Culture metabolites of P. carneus, P. puntoni and P. varioti reduced by 2-3 times diameter of roots of the seedlings of Abeleehi and Obaatanpa although the endodermis and pericycle were clearly formed and demarcated in both the control and treated seedlings. The pith parenchyma was thinly lignified and 2-3 times narrower in diameter in the treated plants exposed to the three Paecilomyces species; pro - and metaxylem vessels were about 2 times wider in the control seedlings and the phloem and xylem regions o f the roots o f the treated plants were reduced in number and size. Maize grains (Abeleehi and Obaatanpa varieties) inoculated with three Paecilomyces species influenced the rhizosphere mycoflora and their succession profile. Generally, the species of fungi that were stimulated, depressed or eliminated varied from one grain variety to another growing either in the field or under greenhouse conditions. Aspergillus flavus, A. niger, A. alutaceus, ( = A. ochraceus) and A. versicolor remained viable in the rhizosphere soil inspite of the presence of the inhibitory principles exuding from the Paecilomyces species; Penicillium citrinum could tolerate the same metabolites while P. digitatum, P. brevi - compactum did not grow very well in competition with the three Paecilomijces species. Population o f other fungi encountered belonging to the genera Cladosporium, Fusarium, Mucor, Scopulariopsis, Trichoderma and Yeast declined with time. Cladosporium herbarum, F. moniliforme, Mucor sp, Rhizopus otyzae and T. viride survived in the treated soil in competition with the metabolites of the Paecilomyces species. The practical implication of these findings are discussed and future studies suggested.
Assessment of Nutritional Status and Dietary Behaviour of Division One League Footballers in Tamale Metropolis
(University of Ghana, 201-07) Abdulai, K.; Brown, C.; Hayford, F.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Nutrition and Food Science
Background: Football, the most common sports worldwide, is played in almost all nations. Success in football brings reputation, wealth and international recognition but comes as a result of regular physical training with muscular exertions. Good nutrition is an essential tool to help footballers meet the energy demands of training in order to maintain performance capacity and prevent the development of excessive fatigue. Iron also plays an important role in aerobic capacity and performance due to its role as an oxygen transporter to working muscles. Less than adequate iron leads to less oxygen been delivered to muscles, resulting in deterioration of maximal oxygen consumption and reduced performance. Aim: The aim of this study was to assess the nutritional status and dietary behaviour of Division One League (DOL) footballers in the Tamale Metropolis. Methods: The study was cross-sectional. Footballers from five DOL teams in Tamale Metropolis were recruited for the study. A structured questionnaire was used to obtain information about their socio-demographic characteristics. Their food intakes were assessed using a 24-hour recall and a validated food frequency questionnaire (FFQ). Their body fat composition and anthropometric measures were also assessed to determine the nutritional status of the footballers using a bio-impedance analyser after their heights had been taken with a stadiometer. Their full blood count, haemoglobin (Hb) and ferritin levels were also determined. Results: A total of 130 footballers were involved in the study. Seventy-two respondents (60.5%) had normal BMI, 42 (35.3%) were overweight, 3 (2.5%) were obese and 2 (1.7%) were underweight. About 1.7% were anaemic and 91% had low mean corpuscular volume (MCV) values, symptoms of microcytic anaemia. All the footballer had normal ferritin levels. Fruit juice and animal proteins were the least consumed food groups with an average consumption of two times per week (2/7). Soft drinks, vegetable proteins, and tubers were consumed three times a week (3/7), while cereals and grains had the highest frequency of consumption of four times per week (4/7). Plant proteins showed a significant correlation (all p < 0.05) with red blood cells, haemoglobin, and serum ferritin. Animal protein, however, showed no correlations with the blood parameters. Conclusion: The dietary pattern of the DOL footballers showed they had high intake of energy giving foods (cereals and grains and tubers) but low consumption of animal proteins. Footballers with high consumption of animal proteins had better Hb, ferritin, MCV, and RBC levels. The prevalence of anaemia was low (1.7%). The high prevalence of overweight could be due to high levels of percentage muscle mass. The football teams in Ghana should be educated on the need for balanced and nutritionally adequate diets. Further research is needed to determine the relationship between diet and anaemia among footballers in a larger population
Identifying the Influence of Male Household Heads on The Expected Outcomes of ENAM Project Community-Based Interventions
(University of Ghana, 209-06) Hagan, L. L.
It is well documented that microcredit given to women results in increased control of household resources by women, and improves quantity and quality of food available to children in the household. The Enhancing Child Nutrition through Animal Source Food Management (ENAM) project implemented a microcredit plus education intervention aimed at increasing Ghanaian women's access to and utilization of ASF in the diets of2-5 year old children. The current study was designed to assess the role played by the ENAM caregivers' Male Household Heads (MHH) in the caregivers' Income Generating Activities (lGA) and its influence on the Animal Source Food (ASF) intake and nutritional status of their 2-5 year old children. Ninety one MHH in four rural communities in two different ecological zones of Ghana were purposively selected for the study. A structured questionnaire with both open and close ended questions were used to collect information on MHH socio-demographic status, role played in caregivers' IGA and their perceptions on the importance~ of ASF for young children. Energy and nutrient intakes of children under five years in households surveyed were assessed using weighed food record. Nutritional status of the children was assessed using weight and height measurements. Chi-squared statistics was used to test bivariate associations between demographic characteristics of MHH and outcome variables (such as roles played by MHH). Student t-test was used to compare differences in continuous outcome variables of MHH (children ASF intake) who played strong role and weak role. Multiple regression analysis was used to investigate the influence of MHH demographic characteristics on children's ASF intake. The results revealed significant differences between ASF diversity and quantity of children whose MHH played strong roles and weak roles in caregivers' IGA. Children from households where the MHH played strong roles had higher ASF diversity (2.6 ± 1.0 vs 1.5 ± 0.6; p= 0.031) as well as ASF intake (67.0g ± 25.0g vs 20.0g ± 23.9g; p= 0.040). MHH education was also a significant factor in children's ASF diversity and quantity. Children of MHH with education above primary level consumed significantly higher quantity and diversity of ASF. From the findings it was concluded that when a MHH has education above primary and plays a strong role in caregivers’ IGA a child is likely to consume more ASF both in quantity and diversity, in a household. It is recommended that intervention programmes that aim to empower women as a way of helping families to improve on their children's nutritional status should involve MHH who are mainly husbands of the caregivers to ensure better outcome.
An Investigation of the Behaviour and Biology of the Citrus Mussel Scale, Lepidosaphes Beckii (Newm.)
(University of Ghana, 1960-12) Hulley, P. E.; Ewer, D. W.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)
The citrus industry is subject to a number of serious insect pests. Of these, the most important is a sedentary group known as the...Armoured Scale Insects (Diaspididae). Ebeling (1950) states that they are of greater economic importance to the industry than all the other pests put together. A great deal has been published on various aspects of the biology, ecology and control of the Diaspididae, much of the work appearing in the books of Quayle (193S), Ebeling (1950) and Bodenheimer (l9 5 l)≫ It is very noticeable, however, that the study of the active larvae, or ’’ crawlers” , of these insects has been relatively neglected* This lack of work on crawlers is surprising, since they are the only distributive stage in the life cycle of the species. The adult male is also free - livin g during its brief life span, but takes no part in the actual distribution of the species. I t is the position of the female Scale Insect which is important in determining the further spread of the species, since this is the point from which subsequent crawlers will start out on their wanderings. The stage in the life cycle responsible for the position of the female is, of course, the crawler. The crawler is also responsible for the parallel distribution of the male Scales, so that the female can be fertilised . The r&le oj. tne adult male is confined to the maintenance of the gene flow* From an economic point of view it seems desirable that a complete study be made of the biology of this distributive stage of these important pests. Information on factors influencing the hatching (or birth of ovoviviparous species), and emergence from beneath the scale-covering of the female, would be useful.
Studies on the Effects of Microclimates on the Distribution of Larval Ticks in the Eastern Cape Province
(University of Ghana, 1961-12) Kraft , M.K.
An Investigation into the Clasp Reflex of Xenohis Laevis (Daud)
(University of Ghana, 1962) Hutchison, J. B.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)
Studies on the Physiology and Pathogenicity of Sclerotium Rolfcii Sacc. Causing Fruit - Rot of Tomato (Lycopersicum Esculentum Mill.)
(University of Ghana, 1965-06) Dakwa, J.T.; University of Ghana, College of Basic and Applied Sciences , School of Biological Sciences , Department of Botany
Salerotium rolfsii Sacc. grew best at 27 to 32 C, and maximum infection of tomato fruits occurred at 32°C„ S^_ rolfsii showed a double maximum of growth in relation to pH: a major peak at pH 1+.8 and a minor one at pH 9.31 with a minimum of pH 8.2 in between. Light had no effect on growth. Growth occurred only at 100$ R. H. whereas infection of tomato fruit occurred at a relative humidity of 957° and above. A moisture level of 55% W. H. C. of soil caused the greatest infection, and degree of infection diminished with a deviation in % W. H. C. in either direction from this level. Even though externally supplied thipmine v/as not essential for initiation of growth, subsequent development depended on it„ Thiamine at 25 Mg and 50 Aig supported the greatest growth. rolfsii was capable of using simple as well as complex carbohydrates as sources of carbon. Starch supported the best growth, followed by Maltose, Fructose and Glucose, whilst galactose and cellulose gave the poorest vegetative growth. Of the nitrogen sourcjig^Peptone and Asparagine were best used by the' fungus,"’and the least suitable was Alanine. S. rolfsii can enter the host through the intact fruit skirf. Rate of infection increased almost directly proportional to increase in size of inoculum. Prior to infection, rolfsii formed infection cushions on the fruit wall. Penetration was achieved by hyphae, emerging from the infection cushions, mechanically piercing through the cuticle and epidermis. Growth within the fniiit was both intercellular and intracellular. Pericarp cells were ultimately dissolved by substances produced by the fungus leaving the dead epidermis and cuticle intact. The disease was not seed borne. Tomato fruits of all ages were infected, and Molokai was the only Ghanaian tomato variety whose fruits were completely resistant to 3. rolfsii.
Studies of the Biology of the Species of Tilapia in the Volta Lake
(University of Ghana, 1967-04) Wuddah, A.A
Studies on the Release, Survival And Germination Of Conidia Of Phyllactinia Corylea (Pers.) Karst.
(University of Ghana., 1968-06) Ankora, J.K.
Conidia of P.corylea germinated best at 25 - 28˚c. and germinated well, uniformly and at the same rate at any humidity from zero to 100% R.H., but poorly in liquid water. Germ tubes conidia germinating at lower humidities were short whilst those at high humidities were fairly long. Approximately 30 per cent of both germinated and ungerminated conidia shrivelled when incubated. at 0% R.H. This value decreased with rise in humidity to show shrinkage in only one per cent of conidia held at 100% R.H. The conidia had a brief latent period of germination of 2 - 3 hours. The germinating conidia usually produced a single germ tube and occasionally two. Branching of germ tubes was rare on glass surface but appressoria were freely formed. On the host (Carica papaya) leaf surface the germ tubes grew randomly over the epidermis am equally freely formed appressoria. The appressoria were either terminal, intercalary or lateral. Germ tubes produced at lower humidities collapsed and shrivelled within a few hours after emergence. All germ tubes produced and held at 0% R.H. shrivelled in 11 hours and those at 80.3% R.H. in 30 hours. Those at 92, 96.9 and 100% R.H. showed 94.5, 25.0 and 20.2% of shrivelled germ tubes respectively in 48 hours. The Conidia germinated better in light and produced longer germ tubes but formed fewer appressoria than those incubated in darkness. Conidia stored at 5˚c and at various relative humidities were preserved longest at the higher humidities and died quickest at the lower humidities. Longevity was however brief and did not exceed 20 days at any humidity. Multicellular, non-branching conidiophores, commonly 300 u long, arose perpendicularly from the superficial mycelium. Each was terminated by a generative cell which formed the conidia. Usually only one mature conidium was distinguishable at the tip of the conidiophore. Immediately after maturation of the conidium the generative cell bent approximately at the middle while the two arms of the cell stood at right angles. This movement loosened the attachment of the conidium to the conidiophore and the conidium fell at the slightest disturbance. The bent generative cell then abstricted the next conidia. In still air conidial chains were readily formed. A few conidia germinated whilst still attached to the conidiophore. The conidia matured predominantly in the dark and heaviest crop of spores were obtained in the morning. The rate of bending of the generative cell was the same at 20 and 28˚c., in light and in dark and at 76 and 100% R.H. The ourvature in the generative cell remained unaltered in sucrose solutions and in water. The generative cell was not phototropic Whilst the entire conidiophore
Eco-Physiological Studies on Pistia Sratiotes. L. With Special Reference to its Occurrence on the Volta Lake in Ghana
(University of Ghana, 1970-06) Attionu, R.H.; University of Ghana, College of Basic and Applied Sciences , School of Biological Sciences , Department of Botany
The creation o f the Volta Lake in Ghana provides favourable oonditions for rapid weed growth,, The present report represents an attempt to investigate the in teraction between one o f the economically important weeds on the Lake, P is t ia s t r a t io t e s , L ., and the physicochemical condition o f i t s environment in the f i e l d and laboratory, P is t ia is represented in most reaches o f the Lake but only sheltered bays and es tu arie s in the south are oharaoterized by luxuriant veg etation o f the species. Distribution and growth o f the plant within these areas are con tro lled to some extent by the pH and mineral composition o f lake water. Under laboratory oonditions, marked influence is exerted by substrate pH and nutrient content on the ve g etative reproduction and growth or the plant. Occurrence o f optimum v e g e ta t iv e growth a t low to ta l nutrient content and pH 5»0 is r e f le c te d in the tendenc3r shown by ro s e tte s to grow la r g e r in areas o f the Lake characterised by comparatively low degree o f m ineralization, and pH. Growth of the plant has been observed to a l t e r the pH and mineral content of the substrate under f i e l d and laboratory conditions. The nature o f th is change in the f i e l d depends on the cover o f vegetation. Stranded ro s e tte s which have become rooted in the drawdown area o f the Vo lta Lake are capable o f regenerating and may reco lonize the lake surfaceo Results o f these in v e stigation s have been discussed with reference to methods of con tro llin g the plant,
Nutritional Studies with Specific Reference to Thiamine on Koko a Ghanaian Cereal Product
(University of Ghana, 1970-09) Andah, A.
'Koko' was prepared in the laboratory from Ghanaian maize. The effect of grinding and sieving on the protein content wa3 determined. Protein losses were highest with the coarsest grinding. Starters were used in the fermentation and were found to increase the rate of acid production. Preservation of 'Koko' was carried out by Roller-drying, Spraydrying, Freeze-drying and Canning. The volatile constituents of the flavours were lost during Roller-drying and Spray-drying. Freese- • drying was very successful but it would be too expensive for commercial processing of 'Koko'. It could, however, be used in the laboratory for research, work. Canning of 'Koko' was also successful, though more work on its microbiological aspect is needed to give conclusive results. Thiamine and Riboflavin contents were determined at various stages in the preparation of 'Koko'. Slight losses of these two vitamins occurred during steeping of maize. Fermentation increased Thiamine considerably although only very slight increases were recorded for Riboflavin. The significance of these results are discussed.
The Biology and Ecology of Macromischoides Aculeatus (Hymenoptera: Formicidae) In Cocoa Farms in Ghana
(University of Ghana, 1971-08) Aryeetey, A.E.; Leston, D.; Ewer, D.W.; Kumar, R.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)
The ecology and biology of Macromischoides aculeatus have been studied. The ant was found to be widely distributed in southern Ghana and its distribution overlapped that of the forest zone. In cocoa farms it occurred more commonly and more abundantly in areas with dense shade than in areas of thin shade. Light, predators, homoptera and food availability were found to influence its distribution. It was found to be largely crepusacular and nocturnal. M. aculeatus has been found to be antagonistic to other dominant ants in cocoa farms but could occur together with Crematogaster clariventris on some trees, this depends on a behavioural mechanism. As a predator it utilizes cocoa capsids and other insects, both living and dead, and feeds too on sugars from extrafloral nectaries or from Homoptera. Mites were found as external parasites and nematode worms as internal parasites. Colonies were polydonous and largely monogynous. Population changes are discussed. Alate production uses periodic and flight activity had a peak between April and May when queens founded colonies independently. Presence of brood was found to stimulate nest building in workers. It is suggested that since the ant predates cocoa capsids it could be used as a biological control agent by, at least, encouraging its presence through good cultivational practice rather than, as at present, killing it by the use of broad-spectrum insecticides.
Studies on the Lepidoptera of Cocoa Farms in Ghana
(University of Ghana, 1971-09) Mkhize, S.B.V; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Animal Biology and Conservation Science (DABCS)
Fluctuations in populations of leaf-eating Lepidoptera at Aburi are not only tied up wife availability of food in the form of flushes hut to a certain extent also with the changes in Seasons of the year. Fluking was greatest in February-march at the end of the dry sunny season getting into wet sunny. More caterpillars were seen in the flushes at the time than in the dry month of October-December. Pod-boring caterpillars such as Characoma stictigrapta paused more damage in October-November when there were many pods available. the increase in numbers of Lepidoptera Recies is also associated with cocoa canopy cocoa Trees with a poor canopy harboured much numbers of some lepidopterous species such as Barias Malaga and Anomis leona than trees with a good canopy. Much larger numbers; of caterpillars Occurred in regularly sprayed areas such as at Kade end Safe then at the rarely sprayed farms at Aburi. For instance, the incidence of the pod-husk miner, iiamara sp., was greatest in regularly sprayed farms , probably because, with fee application of insecticides, fee free-flying parasites of Marmara get killed thus upsetting the natural Biological balance.
Some Aspects of the Water Relations of two Mahogany Species
(Univeristy of Ghana, 1971-12) Dodoo, G.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Botany
The general distribution, growth form and economic importance of Khaya senegalensis (Desr) A. Juss. and Khaya ivorensis A. Chev. are described. Some aspects of the water relations of seedlings of these two species, the former a savanna species and the latter a forest species were studied with the view of ascertaining whether moisture plays an important role in determining the pattern of their distribution. Growth of seedlings under four soil watering regimes namely - -0.3 (A), -0,4 (B), -0.8 (C), and -4.5 (D) bars; and under culture solution and culture solution to which polyethylene glycol was added to give the following osmotic potentials (bars): -0.3 (A), -2.8 (B), -5.3 (C), aid -10.3 (D) was studied. The experiment was done in the greenhouse . Growth of K. Senegalensis was more sensitive to moderate moisture stress and less sensitive to high moisture stress. K, ivorensis on the other hand showed less sensitivity to moderate stress but high sensitivity to severe stress. However when soil moisture stress was -0.3 bars, growth of K. ivorensis was very poor. This was attributed to a reduction in root permeability due to poor aeration as a result of more permanent near saturation of the soil. Studies of diurnal patterns of plant water status were carried out by examining leaf relative water content, (R.W.C.) leaf water potential (L.W.P.) and stem diameter variation, in relation to soil moisture stress. R.W.C. was overall higher in seedlings of K. senegalensis than in those of K. ivorensis. L.W.P. on the other hand was lower for IC. senegalensis than for K. ivorensis seedlings. Stem shrinkage decreased with decrease of soil moisture content from 100 to about 50%, field capacity. The decrease in K. senegalensis was greater than in K. ivorensis-. However at 27% field capacity, shrinkage in K. senegalensis was consistently reduced more than in K. ivorensis. This may indicate better water conservation by the former species. Transpiration was also studied in relation to the soil moisture treatments, both in the greenhouse aid in the research room, the latter being a semi-controlled environment where temperature, relative humidity and light intensity were precisely known. The transpiration of seedlings growing in osmotic solution was also studied in the greenhouse, employing stresses of -0.3 and -10.3 bars. Transpiration generally decreased with moisture stress in the root medium. In the research room transpiration of K. senegalensis was higher than that of IC. ivorensis under all soil treatments. In the greenhouse, however, similar higher transpiration rates were recorded for K. senegalensis seedlings than for K. ivorensis seedlings when stress was from -0.3 to -0.8 bars, but at severer stresses (-4.5 and -10.3 bars) transpiration of K. senegalensis was reduced more than that of K. ivorensis. Infiltration of leaves of K. senegalensis and K. ivorensis with mixtures of liquid paraffin and commercial Kerosene showed that stomatal conductivity of K. senegalensis leaves was greater than that of K. ivorensis leaves at low moisture stress. At more severe stress (-4.5 bars) conductivity of leaves of both species was low. The desorption curve for K. senegalensis seedlings was above that for K. ivorensis seedlings. Curves of leaves for adult trees of both species were however similar. K. senegalensis leaves could tolerate desiccation better than K. ivorensis leaves. Stomata of K. senegalensis leaves close at higher relative water content values than those of K. ivorensis leaves. The results are discussed in relation to the distribution of these species and to the general ecological problem of the control of plant distribution between forest and savanna in West Africa.
In Vitro Studies on the Effect of Chloroquine Phosphate on the Metabolism of the Rat Red Blood Cells
(University of Ghana, 1972-11) Yeboah, P.O.; Asante, G.S.; Larway, P.F.; Lovelace, C.A.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Biochemistry, Cell and Molecular Biology
Evidence is presented to show that in vitro. (1) High levels of chloroquine phosphate can induce hemolysis in the rat red blood cells; and (2) chloroquine-induced hemolysis is characterised by a fall in GSH levels, unless glucose is present in very high concentrations* Chloroquine phosphate is a member of the 4-aminoquinoline series of drugs used for treating acute malaria due to infection fctj Plasmodium vivdx« Plasmodium falciparum. Plasmodium malariae and Plasmodium ovale. In vitro studies were made on red blood cells incubated with chloroquine phosphate to investigate a possible chloroquine-induced hemolysis in rat red blood cells. A wide range of chloroquine phosphate concentrations were tested. After 4 hours incubation of the mixture at 3?°C; 6,3 1 10~% caused only - 2. hemolysis in the rat red blood cells; whereas 2.5 x 10 !-i chloroquine caused 66,5a hemolysis. Complete hemolysis was however observed when 4.2 x 10 chloroquine phosphate was used in the incubation system. -1 -2 Either 3.78 x 10 M glucose or 2,0 x 10 M ATP protected the red _2 blood cells from hemolysis induced by 2.5 x 10 M chloroquine phosphate. Hemolysis induced by chloroquine phosphate was found to be characterised by (a) a fall in GSH level, and (b) an increase in the osmotic fragility of the rat red blood cells. These characteristics are similar to primaquine- induced hemolysis in -.red blood cells. The possibility is discussed that based upon osmotic fragility studies, the site of hemolytic action of chloroquine phosphate could be directly on the red cell membrane where the drug might interfere with sulfhydryl groups.
Endogenous Levels of Cytokinins in Ageing Cucumber Cotyledons
(University of Ghana, 1974-08) Poku, J.A.G.; Fletcher, R. A.; University of Ghana, College of Basic and Applied Sciences , School of Biological Sciences , Department of Botany
There are several procedures for isolating cytokinins which involve a number of steps including extraction, solvent fractionation and column or paper chromatography. Various combinations of these procedures were tried in an attempt to isolate cytokinins from cucumber cotyledons. It was found that with this tissue it was preferable to omit a few steps to minimize the loss, of cytokinins activity. The endogenous cytokinin levels in etiolated cucumber cotyledons of different ages were estimated and compared with the capacity of the cotyledons to produce chlorophyll after exposure to light. There was a parallel relationship between cytokinin levels and chlorophyll production. The cytokinin levels were highest in 8 day old cotyledons, at which time the production of chlorophyll was also maximal. It is proposed that cytokinins have an important role in chlorophyll production
K.O.A. Mensah The Study of the Factors Affecting The Natural Resistance of the Wood of Terminalia Ivorensis against Termite Attack
(University of Ghana, 1975-04) Ocloo, J.K; Mensah, K.O.A; Tetteh, G.K; Usher, M.B; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Botany
The natural Radial and axial variations in the resistance of the wood of Termihalia ivorensis A* Chev, against damage by subterranean termites were investigated for two trees from the same locality- The damage was studied in relation to specific gravity, the modulus of elasticity, the cross-sectional area of vessels in the wood,, and the water soluble extractives. The correlation between termite damage and these physical, mechanical and anatomical properties have been reported. It was found that the termite resistance of the wood varied significantly in the radial direction. The outerheartwood was less susceptible to damage than the sapwood and the inner-heartwood, The sapwood was less resistant to damage than the inner-heartwood. The termite resistance of the inner-heartwood increased near the top of the tree. Axial variations in the intensity of termite damage were not very pronounced. Termite damage to the wood was inversely correlated with the specific gravity and cross-sectional area of the vessels generally. The susceptibility to damage by termites generally increased with the modulus of elasticity. The specific gravity, modulus of elasticity and the crosssectional area of the vessels were inter-correlated and no one of them could be used alone to predict the termite resistance of T, ivorensis, The water soluble extractives appeared not to improve on the resistance of the wood. The two trees tested showed significant differences in their resistance to termite attack. This means that naturally growing trees of T„ ivorensis obtained from different Forest Reserves in Ghana could be expected to vary widely in their resistance against attack by subterranean termites.
The Study of the Motors Affecting the Natural Resistance of the Wood of Terminalia Ivorensis Against Termite Attack
(University of Ghana, 1975-04) Ocloo, J.K.; Ayensu, G.I.; Aboh, I.J.K.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Botany; University of Ghana, College of Basic and Applied Sciences, School of Engineering, Department of Computer Engineering
The natural Radial and axial variations in the resistance of the wood of Termihalia ivorensis A* Chev, against damage by subterranean termites were investigated for two trees from the same locality- The damage was studied in relation to specific gravity, the modulus of elasticity, the cross-sectional area of vessels in the wood,, and the water soluble extractives. The correlation between termite damage and these physical, mechanical and anatomical properties have been reported. It was found that the termite resistance of the wood varied significantly in the radial direction. The outerheartwood was less susceptible to damage than the sapwood and the inner-heartwood, the sapwood was less resistant to damage than the inner-heartwood. The termite resistance of the inner-heartwood increased near the top of the tree. Axial variations in the intensity of termite damage were not very pronounced. Termite damage to the wood was inversely correlated with the specific gravity and cross-sectional area of the vessels generally. The susceptibility to damage by termites generally increased with the modulus of elasticity. The specific gravity, modulus of elasticity and the crosssectional area of the vessels were inter-correlated and no one of them could be used alone to predict the termite resistance of T, ivorensis, The water soluble extractives appeared not to improve on the resistance of the wood. The two trees tested showed significant differences in their resistance to termite attack. This means that naturally growing trees of T„ ivorensis obtained from different Forest Reserves in Ghana could be expected to vary widely in their resistance against attack by subterranean termites.
Studies on the Physiology of Achlya Megasperma Humphrey Occurring In Ponds on the Accra Plains with Special Reference to Its Tolerance To Organic and Inopganig Pollution
(University of Ghana, 1976-03) Apaloo, C. M.; Clerk, C. C.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Botany
Achlya megasperma sporulated best s.t 30°C and at pH 7.0 to 9.0. Light had no effect on forration of the sporangia. Certain concentrations of CaCl-,., ^ulcitol. Mg SO^^H^O, Malt extract, neptone and Yeast extract enhanced sporangial formation. The mineral salts, CuS04 .5H20, FeCljs MnS04 .4H20 and Zn Cl2 depressed sporangial formation. Gemmae were produced in great quantities in solutions of 0.1, 0.2 and 0,4 per cent haemoglobin and 1x0 ^ and 0_5M Zn Cl^. Sporangial formation was also inhibited by the carbohydrates, Fructose, Galactose, Glucose, Lactose and Mannose, the polyhydrol alcohols Glycerol and Mannitol and, by Potato dextrose broth. Vegetative growth was, however, greatly improved by Potato dextrose broth, Fructose, Glucose, Mannose, Malt extract, Peptone and Yeast extract, and there was considerable hyphal branching in solutions of Fructose Glucose, Malt extract,Peptone and Yeast extract and in Potato dextrose broth. In the mineral salt solutions the range of concentration permitting sporangial formation was narrower than that Supporting vegetative growth. Snorangia which had been delimited from the supporting hyphae were prevented from further development by pfH , provided by distilled water adjusted with 0.5N HC1, and by cow-dunp solution of 10 and dun? per litre of distilled water. There was total inhibition of sporanfrial formation at dunp concentration of 30g per litre of suspending medium. Sporanpia formed under conditions of poor snorulation were markedly smaller in size. A particularly pronounced effect was produced by 20°C, pH 5, lxlO-3 to O.lf CaCl2s lxlO-7 and 1x10'SM CuS04.5H20 and MnS04.4H20, 1x10~5M FeCl^ and 1x10 M ZnCl^ and by the alcohols, Glycerol and Mannitol.
The Partial Purification of Human Erythrocyte Adenylate Kinase and the Effect of Some Common Antimalarial Drugs on this Enzyme
(University of Ghana, 1976-06) Antwi, K.Y.D.; Asante, G.S; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Biochemistry, Cell and Molecular Biology
The enzyme adenylate kinase (AK) was partially purified from human erythrocytes. The purification process involved the separation of the erythrocytes from whole human blood, rinsing of the cells in saline solution and finally lysing them in two volumes of water containing dithiothreitol. The crude haemolysate was dialysed against O.OlM sodium citrate buffer pH 5.0 and then treated with a suspension of CM-sephadex C-50, previously equilibrated in O.OlM sodium citrate buffer pH 5.0 containing 0.25M sodium chloride to reduce amount of haemoglobin present to effect better separation on column. After centrifuging at 30,000g the supernatant solution from this treatment was further subjected to sephadex G-100 column chromatography to obtain a partially purified enzyme preparation. The activity of adenylate kinase was measured using the coupled assay system by Oliver (1957), which is AK 2ADP ------- >AMP + ATP + hexokinase + Glucose + Mg2+ Glucose-6-phosphate + G6PD + NADP+ 6-phospho-gluconate + NADPH + H+ Absorbance at 340nm was measured for the NADPH produced over a period of 6 minutes using an SP 500 spectrophotometer with a recorder attached to it. This corresponded to ATP produced over the same period. It was found that AK was unstable at 70°C and optimum activity was observed around 37°- 40°C. Dilute solutions of AK were found to be unstable, but the enzyme was stable at 4°C in a concentrated form. Adenylate kinase activity was also found to be inhibited at high substrate (ADP) concentration, and it is known that AMP, one of the products of the reaction inhibits AK activity, competitively. From substrate concentration of 3-10mM ADP, the activity decreased. Optimum activity was obtained at substrate concentration of l-2mM ADP. The effect of some common antimalarial drugs on the enzyme activity was also looked at. The antimalarial drugs used included chloroquine diphosphate, chloroquine sulphate, quinine hydrochloride, quinine sulphate, proguanil hydrochloride, primaquine phosphate and mepacrine hydrochloride. All the drugs at a concentration of 10“^M inhibited the enzyme activity to various extent. The degree of inhibition depended on the incubation period of the enzyme with the particular drug. Quinine was found to inhibit the enzyme activity most. Inhibition of up to 62.0% was observed with quinine after 3 hours incubation period. For the same incubation period, primaquine phosphate inhibited the enzyme activity up to 42.0%, mepacrine up to 40.7%, chloroquine up to 30,3% and proguanil hydrochloride up to 28.0%. The type of inhibition, observed for chloroquine diphosphate, the most common antimalarial drug in the tropics, was noncompetitive inhibition.

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