Biotechnology
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Item The Action of Copper Fungicides in the Control of Dothistroma Blight of Pines-A Pilot Study(1970) Gibson I. A. S.; A. K. HowlandExperiments to determine the retention of copper fungicides on the foliage of young Pinus radiata show that there was little difference amongst the rates of weathering of five materials based on copper oxychloride and cuprous oxide after application at the same initial dosage of copper. The rate of weathering of a cuprous oxide formulation was also studied after application at a range of dosages. This showed that high dosages combined with a small number of spray operations might prove more economical than a larger number of operations at a lower dose rate, when copper fungicides were used to control Dothistroma blight of pines in the field. Control of blight by copper fungicides was shown to be related to the fact that the pathogen was highly sensitive to copper in solution. Copper was shown to be trans-located in surface water on the host in quantities toxic to germinating conidia of Dothistroma pini providing protection to foliage and eradicating inoculum established in diseased portions of the tree.Item An Approach for the Calculation of the Biomass Production of Short Growing Periods in the Rangelands of Northern Kenya(1994) Hugmann, J.Investigations on the soil plant water relationship were carried out in the semiarid thorn bush Savannah of Ngare Ndare, Isiolo District, Northem Kenya, to develop an approach for the determination of the biomass production on the basis of the soil:water balance. In order to determine the growth-effective rainfall, the soil-water balance of the short rain periods was correlated with the subsequent growing periods. During the study period, the growth effective rainfall of the different rain periods amounted to an average of 75% of the total rainfall. Due to the highly adapted natural plants of this dwarf shrub bushland, the daily water consumption of the vegetation was below 2 mm/day. High growth effectivity of the rainfall and low water consumption led to long growing periods even after light rainfalls. Based on these observation5, a formula for the calculation of the duration of the growing periods based on daily rainfall and evaporation data was developed.Item Bacteriological Milk Evaluation with Particular Reference to Deoxyribonuclease(1977) Nduka Okafor,; Obi, S. K. C.Milk samples from a dairy farm were bacteriologically evaluated. High mean viable counts were recorded -2.0 X 109/ml for total mesophilic count, 1.9 X 105 /ml for coliforms and 7 X 104 / ml for staphylococci. The bacterial spectrum showed such pathogenic and food poisoning organisms like Escherichia coli. Staphylococcus awreus, Pseudomonas aeruginosa. Bacillus cereus, Clostridium perjringens and Salmonella typhymurium. Weakly DNAse postive isolates and the DNAse negatives tended to have higher percentages of mutants resistance to Streptomycin, Tetracyline and Penicillin G respectively than the DNAse positives. Albout 63 percent of the isolates with multiple resistance were weakly DNAse positives.Item Bio Control of Water Hyacinth with Cercospora Piaropi and Myrothecium Roridum Corn Oil Formulations in the Greenhouse for Enhanced Water Resources Management and Conservation(East African Journal of Science, Technology and Innovation, 2021-05-25) Mutebi, C.M.; Musyimi, D.M.; Opande, G.T.; Kenya Agricultural and Livestock Research Organization ; Maseno UniversityWater hyacinth hinders extraction and supply of clean water by clogging intake systems. Despite control efforts, it has remained resurgent and difficult to manage under current methods. Efficacious control for the weed is therefore necessary. This study’s goal was determination of effect of corn oil spore formulations of Cercospora piaropi Tharp and Myrothecium roridum Tode Fries on; disease intensity, relative shoot length and relative biomass of water hyacinth. It was conducted in Maseno University and in a greenhouse at Kibos in Kisumu situated at latitude 00 37’ S and longitude 370 20’ E. The conditions were 25 to 300 C and 22 to 270 C temperature averages during the day and night respectively and 60 to 69% relative humidity. Isolations of C. piaropi and M. roridium were made, grown on PDA, harvested and formulated in corn oil at 1x105, 1x106, 1x107, 1x108 and 1x109 spores/ml. Healthy plants were misted with the corn oil formulations and placed in 90 cm diameter and 1.5 cm depth plastic basins filled with 20 liters of water that had been kept in a container for 24 hours for chlorine to be released. The experimental design was completely randomized design with three replications. Disease intensity, relative shoot length and relative biomass were determined biweekly for 6 weeks. Analysis of variance on the means was done using SAS Institute, Inc.1999 computer software and LSD (p≤0.05) used for mean separation. Disease intensity, AUDPS, relative shoot length and relative biomass scores for both pathogens showed a significant (p ≤. 05) increase as the concentration of spores in the formulations increased. Cercospora piaropi and M. roridum in corn oil formulation at 1x108 and 1x109 spores/ml were found effective for lowering water hyacinth biomass and shoot growth respectively and with potential for use in open waters for water hyacinth control.Item Biocontrol Potential of Four Indigenous Entomopathogenic Nematodes From Kenya(Canadian Center of Science and Education, 2021-09-15) Ngugi, C.N.; Wachira, P.M.; Mbaka, J.N.; Okoth, S.; Haukeland, S.; Thuranira, E.G.; Kenya Agricultural and Livestock Research Organisation ; University of Nairobi ; International Center of Insect Physiology and EcologyGlobally, vegetable production including tomato is constrained by pests and diseases. The tomato leafminer, Tuta absoluta (Meyrick.), is a major pest of tomato, mainly managed using chemical pesticides. There is a need for integrated pest management (IPM), approaches that are human and environmentally friendly. The study aimed at molecular identification and virulence evaluation of four entomopathogenic nematodes (EPNs) against T. absoluta larvae. The DNA was extracted, sequenced, and phylogeny analyzed. The EPNs virulence was evaluated using the insect baiting technique at different nematode concentrations (0-Control, 100, 150, 200, and 250 infective juveniles/ml of distilled water). Larval mortality data were collected for five days. Molecular identification resulted in nucleotide sequence lengths of 877-895 base pairs (bp). All the isolates were found to be Steinernema species of EPNs. The % similarity of the isolates and their close relatives ranged between 82-100%. The isolates closely matched Steinernema spp. AY230184 (Sri Lanka); AY230186 (Kenya), JN651414 (Ethiopia), and MW151701 (Kenya). The sequences were deposited to Genbank as Steinernema sp. Isolate Kalro 75 (MW150871), Steinernema sp. Isolate Kalro S86 (MW150872), Steinernema sp. isolate Kalro97 (MW150873) and Steinernema sp. Isolate KalroR52 (MW150874). All the EPN isolates were virulent against T. absoluta. Isolate Kalro R52 and Kalro S86 recorded the highest mortality of 76±7.5%; 72±15.0% respectively in the 48 h. There was a significant difference (P < 0.001), between all the isolates and the Control. The four EPNs were virulent and have bio-control potential against, T. absoluta. Research on their virulence against T. absoluta in the field is recommended.Item Biofortification of Common Bean (Phaseolus Vulgaris L.) with Iron and Zinc: Achievements and Challenges(John Wiley & Sons Ltd., 2022-06-30) Huertas, R.; Karpinska, B.; Ngala, S.; Mkandawire, B.; Maling, J.; Wajenkeche, E.; Kimani, P.M.; Boesch, C.; Stewart, D.; Hancock, R.D.; Foyer, C.H.; The James Hutton Institute ; University of Birmingham ; University of Nairobi ; The Food, Agriculture and Natural Resources Policy Analysis Network (FANRPAN) ; Kenya Agriculture and Livestock Research Organization (KALRO) ; University of Leeds ; Heriot-Watt UniversityMicronutrient deficiencies (hidden hunger), particularly in iron (Fe) and zinc (Zn), remain one of the most serious public health challenges, affecting more than three billion people globally. A number of strategies are used to ameliorate the problem of micronutrient deficiencies and to improve the nutritional profile of food products. These include (i) dietary diversification, (ii) industrial food fortification and supplements, (iii) agronomic approaches including soil mineral fertilisation, bioinoculants and crop rotations, and (iv) biofortification through the implementation of biotechnology including gene editing and plant breeding. These efforts must consider the dietary patterns and culinary preferences of the consumer and stakeholder acceptance of new biofortified varieties. Deficiencies in Zn and Fe are often linked to the poor nutritional status of agricultural soils, resulting in low amounts and/or poor availability of these nutrients in staple food crops such as common bean. This review describes the genes and processes associated with Fe and Zn accumulation in common bean, a significant food source in Africa that plays an important role in nutritional security. We discuss the conventional plant breeding, transgenic and gene editing approaches that are being deployed to improve Fe and Zn accumulation in beans. We also consider the requirements of successful bean biofortification programmes, highlighting gaps in current knowledge, possible solutions and future perspectives.Item Biotechnology Research And Application For Kenya(Kenya Agricultural Research Institute, 1990) Kenya Agricultural Research InstituteThe principal objective of the workshop is to bring Kenyan scientists together to discuss the present and future role of plant biotechnology in Kenya. Tissue culture and other novel technologies for improving quality and increasing efficiency of production of agricultural crops and commercial products of industrial use will be the focus for discussion.Item Blood Plasma Urea and Ammonia Concentrations of Grazing and Grazing-Supplemented Ruminants in a Humid Tropical Environment(1987) Adegbola, T.A; Okorie, A.U; Aharanwa, J.C; Eruchalu, M.CThe concentration of blood plasma urea nitrogen (BUN) and blood ammonia nitrogen (BAN) was determined using 8 each of West African dwarf sheep, West African dwarf goats, Boran cattle, Ndama cattle, and Muturu cattle. Each group of 8 animals was further divided into two sub-groups of 4 animals; one subgroup was maintained by grazing only while the other was grazed and supplemented with concentrate. This procedure was adopted in both experiments 1 and 2. In Experiment 1, sheep had the highest BUN with values of 3.21 and 2.66 mg/1oo ml for unsupplemented and supplemented animals respectively, followed by goats (2.92, 2.43), Boran (2.65, 1.63), Ndama (2.54, 1.60) and Muturu (2.44, 1.42). The BUN concentrations were significantly depressed (P < 0.05) in supplemented animals. Values of BUN were generally lower in Experiment 2 than in Experiment 1 and the order was also altered; goats had the highest, followed by sheep, Ndama, Boran and Muturu cattle. The BAN followed almost the same pattern as the BUN and BAN values were depressed on supplementation with concentrate. The generally low values for BUN indicate inadequacy of dietary nitrogen for the animals.Item Bloodmeal Host Identities Among Sympatric Glossina Austeni and Glossina Pallidipes Tsetse Flies in Shimba Hills National Reserve, Kwale, Kenya(Frontiers, 2023-04-14) Ogolla, K.O.; Onyango, T.; Bwana, B.K.; Otiende, M.Y.; Mang’era, C.M.; Ochieng, B.; Omolo, M.O.; Mugambi, J.M.; Hassanali, A.; Omondi, P.; Mireji, P.O.; Kenya Agricultural and Livestock Research Organization ; Wildlife Research and Training Institute ; Egerton University ; Masinde Muliro University of Science and TechnologyOdor from preferred/non-preferred tsetse fly vertebrate hosts have been exploited in R&D of attractants/repellents of the fly for human and livestock protection. Odors from vertebrate hosts of Glossina austeni and Glossina pallidipes tsetse flies can facilitate formulation of novel attractants effective against G. austeni or improvement of existing attractant blends for G. pallidipes. We compared vertebrate blood meal sources of both fly species at Shimba Hills National Reserve, Kenya, to establish putative preferred host of either species, hence potential source of G. austeni or G. pallidipes specific odors. We trapped sympatric adult flies in 2021 and 2022 using NGU traps/sticky panels baited with 3-propylphenol, octenol, p-cresol, and acetone (POCA), collected their blood meals and characterized the meals using High Resolution Melting (HRM) vertebrate 16S rRNA- PCR (for host identification), and compared host profiles using GLM and Fisher’s exact tests. We collected 168 and 62 sympatric G. pallidipes and G. austeni with bloodmeal, respectively in 2021 and, 230 and 142 respectively in 2022. In 2021, we identified putative hosts of 65.48 and 69.35% of the G. pallidipes and G. austeni respectively and 82.61 and 80.28%, respectively in 2022. In 2021, we detected harnessed bushbuck, buffalo, common warthog and cattle putative host bloodmeals, and additionally bushpig and suni antelope bloodmeals in 2022. Putative vertebrate bloodmeal sources were significantly different by tsetse fly species (χ²(1, N=457) = 43.215, p < 0.001) and sampling year (χ²(1, N=457) = 8.044, p = 0.005). Frequency of common warthog bloodmeals was higher in G. pallidipes (65.79%) than in G. austeni (38.60%), and that of suni antelope and harnessed bushbuck putative bloodmeals higher in G. austeni (21.05-28.07%) than in G. pallidipes (6.84 - 17.37%) in 2022. There was an apparent change in putative feeding preference/host choices in both fly species between 2021 and 2022. Host bloodmeals in G. pallidipes or G. austeni predominantly from putative harnessed bushbuck, suni antelope or common warthog reveal that these vertebrates have potential odors that can be harnessed and formulated into appropriate attractants for respective species and integrated into routine control regiment for G. pallidipes and/or G. austeni.Item The Breeding Behavior of Molasses Grass in Kenya(1960/1961) Bogdan, A.V.; Grassland Research Station, Department of Agriculture, Kitale, KenyaIn 1954 the comparison and selection of varieties of Molasses grass (Melin is minutiflora Beauv.) suitable for leys was undertaken at the Grassland Research Station, Kitale. This type of work necessitates a certain knowledge of the breeding behavior of the species concerned and as no information could be found in the literature a study of progeny lines was Undertaken to find out whether Molasses grasses are cross-pollinated or self-fertile. Four distinct varieties were chosen for this study. They differed in general habit, and in such characters as the nature of the hairs on the leaf sheaths close to the nodes, the colour of the leaves, the hairiness of the spikelets, the length of the awns, and other features. For the purpose of strain building, the fact that Molasses grass is not a cross-pollinatzd species indicates that strains can be developed from single selected plants, and it also indicates that varieties can be grown for seed without the need for isolation, as far as cross pollination is concerned. A revision of the M. minutiflora complex and its affinities, including observations on progeny lines, is required before the taxonomy of this group can be clearly resolved.Item C3, C4 Photosynthetic Types and C4 Kranz Sub-Types: Occurrence, Distribution, and Photosynthesis(1968) Imbamba S.K; Macharia J.N.MStudies on the occurrence, distribution, and photosynthesis of C3 , C4 photosynthetic systems and C4 Kranz sub-types were carried out from four natural grassland ecosystems located in Masai Mara, Aberdare, Nairobi, and Amboseli National Parks. The four sites differed in several environmental factors including temperature, occurrence and distribution of C, and C4 photosynthetic systems and C4 Kranz sub-types in grasses was examined on the basis of leaf anatomy. Out of 92 grass species studied 87%, 13% were Kranz (C4) and non-Kranz (C3) respectively while 36, 22 and 42% of the C4 species were PEP-ck, NAD-me and NADP-me sub-types respectively. Grasses collected from Masai Mara, Nairobi, and Amboseli were all C" while 65 and 35% of the Aberdare species were C4 and C3 respectively. Thus, the Aberdare site (all >3,000 m) lies in a transitional zone inhabited by both C, and C4 species; the latter being dominated by species in Andropogoneae and Paniceae tribes. C4 species were generally found at lower altitudes while C3 species occupied higher altitudes. An analysis of the distribution of the Kranz sub-types in the grass tribes revealed that species in the Aristideae, Andopogoneae and Arun- dinelleae tribes were NADP-me sub-types while species in Pappophoreae tribe were PEP-ck sub-types. All other tribes were promiscuous; Eragrostideae and Paniceae tribes, for example, contained species with all three Kranz sub-types. Malate formers (NADP-me) were more dominant in areas with high soil moisture while PEP-ck occurred in areas of medium soil moisture; NAD-me were dominant in areas with low soil moisture. CO2 gas exchange studies showed that the C4 species exhibited higher rates than their C3 counterparts. However, C4 species from high altitudes exhibited low CO4 exchange rates than those collected from low altitudes. Measurements in high altitude C" grasses left to adapt at low altitude for one year clearly showed that although the temperature optimum for photosynthesis remained the same (20-2SoC) the maximum rate increased substantially from the original 45-55 mg CO2 dm-2 per hr to 65-75 mg CO2 dm-2 per hr.Item The Camel and Food Security in Northern Districts of Kenya(Animal Production Society of Kenya, 2001) Kuria, S.; Mbui, M.; Animal Production Society of KenyaA study was carried out in Marsabit, Turkana, Laikipia, Samburu and Wajir Districts to document the production and phenotypic characteristics of Rendille, Gabra, Turkana, Somali and Pakistan camels. This was to form the basis for selection and breeding to improve productivity of Kenyan camels. Production data was collected from KARl and FARM-Africa camel herds in Marsabit and Samburu and Laikipia Districts. Phenotypic data was collected by taking measurements on various body parts of camels using a tape measure. The results showed that Pakistan (P) is the highest (P < 0.05) milk yielder followed by Somali (S) while Rendille (R) and Turkana (T) had similar yields. Crosses of S with T and S with R yielded similar amounts (P < 0.05) as purebred R and Turkana. However, crosses of P with S were higher yielders than pure Somali. Birth weights of S, Rand T breeds were statistically similar while P x S calves were heavier than pure Somali (P < 0.05). Pakistan and S camels were the biggest in followed by Gabra (G) whereas either R or T were the fourth biggest depending on the sex. In conclusion, the types were Phenotypically different (P < 0.05). Pakistan camel is likely to be of different genetic background from Somali, Rendille and Turkana.Item Chemical and Microbiological Studies on Congolese Palm Wines. (Elaeis guineensis)(1971) Swings, J.G.; Van Pee, W.; Laboratoire de Microbiologie, Université Lovanium, Democratic Republic of the Congo (Kinshasa)The presence of seven organic acids and 25 amino-acids was followed by paper-chromatography during the palm Juice fermentation.The vitamin BI2 content of palm juice and young palm wine was determined by a microbiological assay wIth Lactobacillus leichmannii ATCC 7830. Some micro-organisms not previously known from palm wine were isolated and identified VIZ.: Saccharomyceses chevalieri S. pasforianus, S. ellipsoides and a very interesting ethanol-producing bacterium:Zymomonas congolensis sp.n.Item Chemical Control of Insect Pests of Kenaf (Hebiscus Cannabinus) With Pirimiphosmethyl Ulv Formulation(1979) W. K. Kaya; W. W. LuhanpA field trial to control insect pests of Kenaf (Hibiscus cannabinus) with Pirimiphos-methyl ULV formulation was conducted in 1976. Results were assessed by insect population counts taken at 24 hours intervals. Pirimiphosmethyl applied at 1.0 kg ai/ha and 0.5 kg ai/ha effectively controlled Oxycarens Canabinus, Dysdercus spp and Podagrica weisei.Item Comparative Compositional Analysis of Cassava Brown Streak Disease-Resistant Cassava 4046 and Its Non-Transgenic Parental Cultivar(Taylor & Francis Online, 2021-11-04) Wagaba, H.; Kuria, P.; Wangari, P.; Obiero, A.H.; Beyene, G.; Alicai, T.; Bua, A.; Esuma, W.; Nuwamanya, E.; Gichuki, S.; Miano, D.; Raymond, P.; Kiggundu, A.; Taylor, N.; Zawedde, B.M.; Taracha, C.; MacKenzie, D.J.; National Crops Resources Research Institute ; Kenya Agricultural and Livestock Research Organization ; Institute for International Crop Improvement ; Donald Danforth Plant Science Center ; University of Nairobi AG SCI Consulting.Compositional analysis is an important component of an integrated comparative approach to assessing the food and feed safety of new crops developed using biotechnology. As part of the safety assessment of cassava brown streak disease resistant 4046 cassava, a comprehensive assessment of proximates, minerals, amino acids, fatty acids, vitamins, anti-nutrients, and secondary metabolites was performed on leaf and storage root samples of 4046 cassava and its non-transgenic parental control, TME 204, collected from confined field trials in Kenya and Uganda over two successive cropping cycles. Among the 100 compositional components that were assessed in samples of 4046 and control TME 204 cassava roots (47 components) and leaves (53 components), there were no nutritionally relevant differences noted. Although there were statistically significant differences between the transgenic and control samples for some parameters, in most cases the magnitudes of these differences were small (20%), and in every case where comparative literature data were available, the mean values for 4046 and control cassava samples were within the range of normal variation reported for the compositional component in question. Overall, no consistent patterns emerged to suggest that biologically meaningful adverse changes in the composition or nutritive value of the leaves or storage roots occurred as an unintended or unexpected consequence of the genetic modification resulting in 4046 cassava. The data presented here provide convincing evidence of the safety of 4046 cassava with respect to its biochemical composition for food and feed, and it could be considered as safe as its non-transgenic control.Item Comparative Trials of D.D.T. and Dieldrin for The Control of the Riverside Tsetse Glossina Palpalis Fuscipes (Newst.)(1957) Burnett G. F; Robinson J.Residual deposits of DDT have been used with considerable success against the tsetsefly, Glossina pa'pu/is jllscipes (NewsL), in the Nyanza Province of Kenya (Wilson, 1953). It has become standard practice to use "Arkotine",a product of Shell Chemicals Ltd. The tests here described were originally intended to give more accurate information than that hitherto available on the persistence of the formulation as used, and if possible :0 suggest economies.Item Comparison of X-rays, Spectrochemical and Chemical Analyses for Micronutrients in Plant Tissues(1979) Pinkerton A.; Theisen A. A.New instrumental methods of analysis have the advantage of speed and simplicity but may sacrifice accuracy. One such method, Spectro chemical analysis, has been used with considerable and widespread success. Recently, interest has been focused on the vacuum X-ray spectrograph as a tool for elemental analysis. This has the great advantage of being non-destructive and of being able to handle a large number of samples with a minimum of preparation.Item The Contribution of Desmodium Uncinatum to the Yield of Setaria Sphacelata(1972) Thairu D. M.A trial evaluating the productivity of Desmodium uncinatum when grown in association with Nandi Setaria is described. Yields of dry matter and nitrogen are given. The total dry matter and nitrogen yield of Nandi Setaria/ Desmodium uncinatum treatment were consistently higher than those of the grass alone receiving no fertilizer nitrogen. The yield of nitrogen from the grass component was slightly improved by presence of the legume during the last three years of the trial. The response of the grass to fertilizer nitrogen was good during the trial period.
