Biotechnology
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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 Effect of Cercospora Piaropi Tharp and Myrothecium Roridum Tode Fries Formulated as Corn Oil Emulsion on Water Hyacinth Shoot Growth Under Greenhouse Conditions(SciCell Publishing Company, 2021-03-31) Mutebi, C.M.; Opande, G.T.; Musyimi, D.M.; Kenya Agricultural and Livestock Research Organization ; Maseno UniversityA study was done to find out the comparative effect of Cercospora piaropi Tharp and Myrothecium roridum Tode Fries formulated as corn oil emulsion on water hyacinth shoot growth and biomass under greenhouse conditions. The study site was located in Kibos at latitude 0037’S and longitude 37020’E with average temperature of 25 to 300C and 22 to 270C during the day and night respectively, and 60 to 69% relative humidity. Healthy water hyacinth plants were inoculated with the pathogens formulated in corn oil at 1x109, 1x108, 1x107, 1x106 and 1x105spores/ml. The control plants were not inoculated. The experiment was set up in completely randomized design (CRD) with each treatment replicated three times. At weeks 2, 4, and 6 after inoculation, the average shoot length and biomass for the treated basins were separately compared to the average shoot length and biomass of the control plants. Increase in spore density for both pathogens significantly increased relative shoot length and relative biomass. Relative shoot length was 55.07 and 51.93 for C. piaropi and M. roridum respectively at 1x109 spores/ml while relative biomass was 73.53 for C. piaropi and 37.60 at 1x109 spores/ml. Inoculation suppressed shoot elongation and biomass with 1x109 spores/ml being most effective. Cercospora piaropi formulated in corn oil lowered shoot length and biomass of water hyacinth more than M. roridum did.Item Harnessing Acremonium Zonatum (Sawada) Gams Oil Formulations as Water Hyacinth Control Mycoherbicides(SciCell publishing, 2021-09-30) Mutebi, C.; Opande, G.; Kenya Agricultural and Livestock Research Organization ; Kaimosi Friends University CollegeThe effect of formulating Acremonium zonatum (Saw.) Gams in corn oil, mineral oil and glycerol was determined in a glasshouse at Maseno University Botanic Garden and laboratory. The study was situated at latitude -100’ 00’’ S and longitude 340 36’ 00’’E. A. zonatum was aseptically isolated from symptomatic plants and inoculated upon healthy water hyacinth plants in a CRD experiment. Data was analyzed using SPSS version 20 computer software. Oil and spore density effects were statistically significant at p < 0.05. The main effect of oil yielded an effect size of 0.281 indicating that 28.1 % of the variance in disease severity was explained by the oil formulation (F(2, 28) = 5.459, p = 0.01). Spore density yielded an effect size of 0.326 indicating that 32.6% of the variance in the study was explained by spore density (F(3, 28) = 4.515, p = 0.011). The interaction effect was not significant (F(6, 28) = 0.199, p = 0.974) indicating that there was no combined effect for the kind of oil used in the formulation of the A. zonatum and the spore density. The results suggested that A. zonatum pathogenicity varies with different spore concentrations, 1x 108 spores/ml being the most potent. A. zonatum has favorable characteristics for consideration as a mycoherbicide. Corn oil as formulation material was concluded to be the best formulation material for A. zonatum.Item Kenyan Farmers Appreciate the Higher Yield of 50% Non-Pollen Producing Maize (Zea Mays) Hybrids(Cambridge University Press, 2023-05-23) de Groote, H.; Ndegwa, M.K.; Muriithi, N.; Munyua, B.G.; Collinson, S.; Olsen, M.S.; International Maize and Wheat Improvement Centre (CIMMYT) ; University of Greenwich ; Kenya Agricultural and Livestock Research Organization (KALRO) ; Corteva AgriscienceIncorporating the dominant male sterile gene, Ms44, in new maize varieties results in 50% non-pollen producing (FNP) varieties. This makes the varieties more nitrogen efficient and increases yield directly by an average of 200 kg ha−1 across yield levels. However, as half of the plants do not shed pollen, the presence of Ms44 in an FNP variety is clearly visible. This technology can improve food production and security in the African maize-based agri-food systems, but only if accepted by farmers. Farmers were therefore invited to 11 on-farm, researcher managed trial sites of FNP varieties in Kenya over 2 years. They were asked to identify the traits they find important in evaluating maize varieties and to score the FNP varieties, as well as their conventional counterparts, on these criteria (including yield, resistance to pests, and cob size) and overall, using a five-point hedonic scale. In total, 2,697 farmers participated, of which 62% were women. Farmers mentioned many traits they find important, especially yield and related traits, early maturity, and drought resistance, but also tassel and pollen formation. In 2017, mid-season, participants scored FNP varieties lower than conventional varieties on tassel and pollen formation, indicating that farmers could distinguish the trait. FNP varieties still received higher scores for yield and overall evaluation. In mid-season 2018, participants no longer scored FNP varieties lower for pollen formation as they now understood the technology. In both years, at the end-season evaluation, scores for tassel formation were not different, but participants scored FNP varieties higher for yield and overall. We conclude that farmers recognized the FNP trait but did not mind it as they clearly favored its yield advantage. The FNP technology, therefore, has high potential not only to increase maize yields, food production, and food security in the agricultural systems of Africa but also to increase varietal turnover and the adoption of new, high-yielding, climate-smart maize hybrids.Item Improved SSRs-Based Genetic Diversity Assessment of Coconuts (Cocos Nucifera L.) Along the Coast of Kenya(African Journal of Biotechnology, 2022-11) Masha. J.C.; Muhammed, N.; Njung’e, V.; Oyoo, M.E.; Miheso, M.; Pwani University ; International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) ; Egerton University ; Kenya Agricultural and Livestock Research OrganizationCoconut is the most important cash crop along the Coast of Kenya, yet its genetic diversity has not been fully established. A genetic diversity study of 48 coconut genotypes that were collected along the Coast of Kenya was conducted with 13 polymorphic short sequence repeats (SSRs) markers. SSR analysis was performed using GeneMapper while data analysis was done with PowerMarker and DARwin softwares. The results revealed a total of 68 alleles ranging from 2 to 11 per locus with a mean of 5.23 per marker. Gene diversity and polymorphic information content (PIC) ranged between 0.41 to 0.83 and 0.33 to 0.79, respectively. A neighbour-joining dendrogram grouped the genotypes into three major clusters containing distinct sub clusters. This study underscored that capillary electrophoresis is a more accurate and informative technique for SSRs allele scoring than agarose gels, which was reported in a previous study with the same SSRs markers and coconut genotypes in Kenya. The clusters observed forms the basis to isolate conservation blocks, which are the key to establishing a genebank, since there is no documented coconut genebank for ex-situ conservation in Kenya.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 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 Multiple-Genotypes Transcriptional Analysis Revealed Candidate Genes and Nucleotide Variants for Improvement of Quality Characteristics in Tea (Camellia sinensis (L.) O. Kuntze)(Elsevier Inc, 2021) Maritim, T.K.; Seth, R.; Parmar, R.; Kumar, R.S.; CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) ; CSIR-HRDC Campus ; KALRO-Tea Research InstituteTea quality is a polygenic trait that exhibits tremendous genetic variability due to accumulation of array of secondary metabolites. To elucidate global molecular insights controlling quality attributes, metabolite profiling and transcriptome sequencing of twelve diverse tea cultivars was performed in tea shoots harvested during quality season. RP-HPLC-DAD analysis of quality parameters revealed significant difference in catechins, theanine and caffeine contents. Transcriptome sequencing resulted into 50,107 non-redundant transcripts with functional annotations of 81.6% (40,847) of the transcripts. Interestingly, 2872 differentially expressed transcripts exhibited significant enrichment in 38 pathways (FDR ≤ 0.05) including secondary metabolism, amino acid and carbon metabolism. Thirty-eight key candidates reportedly involved in biosynthesis of fatty acid derived volatiles, volatile terpenes, glycoside hydrolysis and key quality related pathways (flavonoid, caffeine and theanine-biosynthesis) were highly expressed in catechins-rich tea cultivars. Furthermore, enrichment of candidates involved in flavonoid biosynthesis, transcriptional regulation, volatile terpene and biosynthesis of fatty acid derived volatile in Protein-Protein Interactome network revealed well-coordinated regulation of quality characteristics in tea. Additionally, ascertainment of 23,649 non-synonymous SNPs and validation of candidate SNPs present in quality related genes suggests their potential utility in genome-wide mapping and marker development for expediting breeding of elite compound-rich tea cultivars.Item Membrane Localized Thaumatin-Like Protein from Tea (CsTLP) Enhanced Seed Yield and Plant Survival Under Drought Stress in Arabidopsis thaliana(Elsevier, 2021-05-20) Chalo, M.; Asosii, P.; Anish, K.; Sanjay, K.; Biotechnology Division, Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology ; Kenya Agricultural and Livestock Research Organization - Tea Research Institute ; Nagaland UniversityThaumatin-like proteins (TLPs) are pathogenesis-related (PR5) proteins, which are induced in response to various biotic and abiotic stresses. The present work was carried out to clone TLP of Camellia sinensis (CsTLP) and to evaluate the response of transgenic lines of Arabidopsis constitutively expressing CsTLP under drought conditions. Data showed that transgenic lines exhibited lower relative electrolyte leakage and higher water retention capacity as compared to the wild-type (WT) plants under drought stress. In addition, results with confocal microscopy showed CsTLP + GFP fusion protein to be localized in the cell membrane which moved to the intercellular spaces under prolonged drought stress. Expression of CsTLP enhanced seed yield and the plant survival in transgenic lines as compared to the WT plants under drought stress. Results suggested the importance of CsTLP in improving drought tolerance in Arabidopsis.Item Draft Genome Sequences of 2 Strains of Staphylococcus aureus Isolated From Mastitis-Infected Camel in Kajiado County, Kenya(American Society for Microbiology, 2023-07-27) Mwangi, K.; Gachogo, R.; Masila, E.; Ogali, I; Langat, N.; Onywera, R.; Malonza, V.; Wesonga, H.; Maichomo, M.; Murungi, E.; Kenya Agricultural and Livestock Research Organization ; University of Cape Town ; Kisii UniversityWe report the draft genome sequences of two Staphylococcus aureus strains isolated from a mastitis-infected camel in Kajiado County, Kenya. The 2,739,512-bp and 3,025,943-bp draft genomes coding for 2,577 and 2,889 protein sequences, respectively, provide invaluable data for the computational design of a camel mastitis subunit vaccine.Item Multivalent Viral Particles Elicit Safe and Efficient Immunoprotection Against Nipah, Hendra, and Ebola Viruses(Springer Nature, 2022-12-17) Ithinji, D.G.; Buchholz, D.W.; Ezzatpour, S.; Monreal, A.; Cong, Y.; Sahler, J.; Bangar, A.S.; Imbiakha, B.; Upadhye, V.; Liang, J.; Ma, A.; Bradel-Tretheway, B.; Kaza, B.; Yeo, Y.Y.; Choi, E.J.; Johnston, G.P.; Huzella, L.; Kollins, E.; Dixit, S.; Yu, S.; Postnikova, E.; Ortega, V.; August, A.; Holbrook, M.R.; Aguilar, H.C.Experimental vaccines for the deadly zoonotic Nipah (NiV), Hendra (HeV), and Ebola (EBOV) viruses have focused on targeting individual viruses, although their geographical and bat reservoir host overlaps warrant creation of multivalent vaccines. Here we explored whether replication-incompetent pseudotyped vesicular stomatitis virus (VSV) virions or NiV-based virus-like particles (VLPs) were suitable multivalent vaccine platforms by co-incorporating multiple surface glycoproteins from NiV, HeV, and EBOV onto these virions. We then enhanced the vaccines’ thermotolerance using carbohydrates to enhance applicability in global regions that lack cold-chain infrastructure. Excitingly, in a Syrian hamster model of disease, the VSV multivalent vaccine elicited safe, strong, and protective neutralizing antibody responses against challenge with NiV, HeV, or EBOV. Our study provides proof-of-principle evidence that replication-incompetent multivalent viral particle vaccines are sufficient to provide protection against multiple zoonotic deadly viruses with high pandemic potential.Item Draft Genomes, Phylogenomic Reconstruction and Comparative Genome Analysis of Three Xenorhabdus Strains Isolated From Soil-Dwelling Nematodes in Kenya(Microbiology Society, 2023-05-22) Awori, R.M.; Waturu, C.N.; Pidot, S.J.; Amugune, N.O.; Bode, H.B.; Goethe University ; Kenya Agricultural and Livestock Research Organisation ; University of Melbourne ; University of Nairobi ; Max Planck Institute ; Phillips University MarburgAs a proven source of potent and selective antimicrobials, Xenorhabdus bacteria are important to an age plagued with difficult-to-treat microbial infections. Yet, only twenty-seven species have been described to date. In this study, a new Xenorhabdus species was discovered through genomic studies on three isolates from Kenyan soils. Soils in Western Kenya were surveyed for steinernematids and Steinernema isolates VH1 and BG5 were recovered from red volcanic loam soils from cultivated land in Vihiga and clay soils from riverine land in Bungoma respectively. From the two nematode isolates, Xenorhabdus sp. BG5 and Xenorhabdus sp. VH1 were isolated. The genomes of these two, plus that of X. griffiniae XN45 —this was previously isolated from Steinernema sp. scarpo that also originated from Kenyan soils— were sequenced and assembled. Nascent genome assemblies of the three isolates were of good quality with over 70% of their proteome having known functions. These three isolates formed the X. griffiniae clade in a phylogenomic reconstruction of the genus. Their species were delineated using three overall genome relatedness indices: an unnamed species of the genus, Xenorhabdus sp. BG5, X. griffiniae VH1, and X. griffiniae XN45. A pangenome analysis of this clade revealed that over 70% of species-specific genes encoded unknown functions. Transposases were linked to genomic islands in Xenorhabdus sp. BG5. Thus, overall genome-related indices sufficiently delineated species of two new Xenorhabdus isolates from Kenya, both of which were closely related to X. griffiniae. The functions encoded by most species specific genes in the X. griffiniae clade remain unknown.Item Effect of Extraction Ingredients on the Conformation and Stability of Silk Sericin (SS)(MDPI, 2022-10-01) Muindi, M.P.; Lee, J.H.; Kweon, H.; Kasina, M.; Kenya Agricultural and Livestock Research Organization - National Sericulture Research Center ; National Institute of Agricultural SciencesSilk sericin (SS) has different physicochemical properties depending on the extraction technique. In this study, SS was isolated in the presence of ingredients, including 5 to 10% ethanol (EtOH) and 5 to 10% glycine. Furthermore, temperature conditions of 80 °C, 100 °C, and 120 °C were used for 1, 3, and 5 h to evaluate the extraction rates. The extraction, gelation, structural, and cytotoxicity properties of SS extracted under different conditions were investigated. Extraction at 100 °C and 120 °C were found to have the highest SS yield, with 80 °C being the lowest. SS isolated at 100 °C and 120 °C for 1 and 3 h in water, and EtOH gelled at 4 °C in 2 to 3 days and 37 °C in 40 min. Glycine SS extracts were obtained at 100 °C and 120 °C for 1 h, gelled at 4 °C for 20 days and 37 °C for 16 h. SS was observed at 80 °C, with no gelation occurring. Glycine SS extracts obtained for 3, and 5 h at 120 °C showed no gelation. Circular dichroism (CD) results show glycine in SS induces α-helix and random coil structure. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and fast performance liquid chromatography (FPLC) were used to quantify the molecular weight distribution at 63 and 70 kDa, respectively. The MMT assay (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) revealed no cytotoxicity in macrophage RAW 264.7 cells treated with this method SS; these findings present the significance and possibility of using selected extraction ingredients in SS that allow for the application of native SS at an initial extraction viscosity.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 Silk Fibroin Conjugated with Heparin Promotes Epithelialization and Wound Healing(MDPI, 2022-08-30) Hama, R.; Aytemiz, D.; Moseti, K.O.; Kameda, T.; Nakazawa, Y.; Tokyo University of Agriculture and Technology ; National Agriculture and Food Research Organization ; Kenya Agricultural and Livestock Research OrganizationSilk fibroin (SF) has attracted attention as a base biomaterial that could be suitable in many applications because of its shape and structure. Highly functional SF has been developed to promote tissue regeneration with heparin conjugation. However, the hydrophobic three-dimensional struc-ture of SF makes it difficult to bind to high-molecular-weight and hydrophilic compounds such as heparin. In this study, sufficient heparin modification was achieved using tyrosine residues as reac-tion points to improve cellular response. As it was considered that there was a trade-off between the improvement of water wettability and cell responsiveness induced by heparin modification, in-fluences on the structure, and mechanical properties, the structure and physical properties of the SF conjugated with heparin were extensively evaluated. Results showed that increased amounts of heparin modification raised heparin content and water wettability on film surfaces even though SF formation was not inhibited. In addition, the proliferation of endothelial cells and fibroblasts were enhanced when a surface with sufficient heparin assumed its potential in assisting wound healing. This research emphasizes the importance of material design focusing on the crystal structure inher-ent in SF in the development of functionalized SF materials.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 On-Farm Performance Of Sahiwal -Zebu Crossbreds From Birth To 12 Months Of Age In Trans mara(Kenya Agricultural Research Institute, 1998) Kenya Agricultural Research InstituteLow genetic potential for growth has been identified as a constraint to increased productivity of the local Zebu cattle (Gregory and Trail, 1981). Performance of Zebu cattle can be improved in the production environment by systematic introduction of genes from the Sahiwal breed to increase growth potential. Zebu cattle have low growth rates and attain age and weight at first service at an older age (Saeed et al. 1987). This results in low reproductive ratesand prod uctivity. It is important to evaluate the effects of factors affecting calf growth so that appropriate interventions can be devised to improve animal performance. This study was conducted to identify and quantify factors affecting the performance of Sahiwal - Zebu crossbreds from birth to 12 months of age.
