http://41.89.164.27:8080/xmlui/handle/123456789/208 Mon, 13 Apr 2026 14:14:33 GMT 2026-04-13T14:14:33Z http://41.89.164.27:8080/xmlui/handle/123456789/2553 CHARACTERIZATION OF SELECTED KENYAN COWPEA CULTIVARS FOR TOLERANCE TO ACIDITY SANG, JANETH Acid soils are normally deficient in available phosphorus and have high levels of soluble aluminium. Crops vary in sensitivity to acidity and associated stresses. Kenyan varieties of cowpea have not been tested for tolerance to acidity and phosphorus deficiency. This study was conducted to assess the response of selected cowpea cultivars to acidity and aluminium stress under laboratory and field conditions. A total of nine cowpea cultivars namely UOE-COWPEA-1, UOE-COWPEA-2, UOE-COWPEA-3, UOE-COWPEA-4, UOE-COWPEA-5, KENKUNDE-1, K-80, M-66 and KVU-27-1, were screened in culture solution containing 0 µM and 185 µM AlCl 3 at a pH of 4.3 and four which showed a greater ability to modify the culture solution pH and a higher relative net root length were further evaluated in the field. pH values of the culture solution were taken daily for a period of six days without adjustment. Root and shoot lengths were measured and recorded after six days. The field experiment were laid out in RCBD, where the two main plots were either limed (4 t/ha) or not limed. The treatments were phosphorus (TSP) (0.06 t/ha), lime, phosphorus plus lime and control (-P, -L) and four cowpea cultivars; UOE-COWPEA-2, KVU 27-1, K-80 and KENKUNDE-1 were grown for a duration of four months. Soil samples were analyzed prior to and after planting. Plant height, total number of leaves per plant, total number of branches per plant, leaf area per plant, plant biomass, number of pods per plant, pod length, number of seeds per pod, 100 seed weight and seed yield per plant were assessed using standard procedures. The nine cowpea cultivars screened increase the pH of the culture solution as the days progressed. The increase in the culture solution pH could be due to cowpea cultivars secreting chelating agents that reduce H + thereby increasing the culture solution pH and reducing Al toxicity. UOE-COWPEA-4 cultivar grown at 185 µM Al was the most tolerant with higher relative net root length (75.6%) while UOE-COWPEA-1 cultivar was the most Al sensitve (63.7%). Lime increased the soil pH from 5.23 to 6.37 while both P+L increased soil P to the maximum of 28.93 mg/kg with K-80 cultivar. UOE-COWPEA-2 produced the greatest number of leaves (52) and number of pods per plant (59) while K-80 yielded the highest total seed weight per plant (42g) with KENKUNDE-1 recording the greatest number of seeds per pod (12) all under phosphorus plus lime treatment. UOE-COWPEA- 2, UOE-COWPEA-4, UOE-COWPEA-5, K-80 and KEN-KUNDE-1 cultivars that showed greater promise in modifying the pH, superior growth and yield attributes, could be grown in acidic soils. The cultivars can be tested further to establish their stability in alleviating acidity. Wed, 01 Jan 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2553 2025-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2539 Investigation of the morphological variation among taxa to determine species diversity within Cyperus dives complex in East Africa: a review Tallam, Jerop; Otieno, Donald Fredrick; Musili, Paul Mutuku The Cyperus dives complex, a group within the Cyperaceae family, exhibits substantial morphological diversity across East Africa, presenting a valuable opportunity for studying species diversity and ecological adaptation. This investigation explored the morphological variation among taxa within this complex to assess species diversity and inform conservation strategies. Through a detailed examination of leaf shape, inflorescence structure, and reproductive features, the study reveals significant variations that delineate species boundaries and highlight adaptive traits. Findings from existing literature affirms the complex interplay between environmental factors and morphological characteristics, illustrating how different taxa are adapted to a range of ecological niches. The results demonstrates that morphological diversity within the Cyperus dives complex is influenced by habitat variability and evolutionary pressures. The study concludes that a comprehensive understanding of morphological variation is essential for accurate species identification and effective conservation management. This investigation contributes to the broader understanding of biodiversity in East Africa and supports the development of targeted conservation strategies to protect the diverse taxa within the Cyperus dives complex. Tue, 01 Apr 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2539 2025-04-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2536 PHYTOCHEMICAL COMPOSITION, ANTIBACTERIAL AND ALLELOPATHIC ACTIVITIES OF Achyranthes aspera AND Tagetes minuta LEAF EXTRACTS JEPTOO, LOYCE Antibiotic resistance remains a significant global health concern to date, putting at risk treatment options. As a result, treatments can be expensive and ineffective. It is therefore necessary to look for new options like using plant extracts with antimicrobial properties. Achyranthes aspera and Tagetes minuta have been traditionally used to treat various diseases in many communities and may possess antibacterial and allelopathic properties. Weeds cause more crop losses than insects, pests and diseases combined however their antimicrobial and allelopathic properties have not received much attention. This research aimed to determine the phytochemical composition, antibacterial and allelopathic activities of Achyranthes aspera and Tagetes minuta. Leaves were identified from the farm fields of University of Eldoret, collected, placed in sample collection bags, then transported to the laboratory. The leaves were washed, shade dried then ground to semi-powdery form. Extraction was conducted using sterile distilled water and ethanol. Extracts were tested against Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 51299, Klebsiella pneumoniae ATCC 700603, Pseudomonas aeruginosa ATCC 27853 and Staphylococcus aureus ATCC 29213 by disc diffusion method in a Completely Randomized design with three replications. Ciprofloxacin was used as a positive control. Clear zones around the discs were recorded as inhibition zones in millimetres. Maize, millet, rice and sorghum seeds were dressed with extracts to establish their allelopathic activities by placing five surface sterilized seeds in each petri dish. Fifteen millilitres of extracts were used with distilled water set as a positive control. The design of the experiments was Completely Randomized with three replications. ANOVA was used to determine statistical significance at P ≤ 0.05. A. aspera and T. minuta extracts showed significant inhibitory effects with inhibition zones of ≥13 mm compared to ≥17 mm from ciprofloxacin. Bio-activity of extracts was highest on S. aureus followed by E. faecalis then P. aeruginosa then E. coli with least effect on K. pneumoniae. Plumule and radicle lengths of the test plants were also significantly affected with percentage reductions of ≥63%. Extracts were more detrimental on Rice followed by Maize then Sorghum with minimal effect on Millet. Millet recorded the highest germination percentage of 89.44% while rice had the lowest percentage at 67.78%, with Maize (87.50%) and sorghum (85.83%). Alkaloids, coumarins, flavonoids, phenols, quinones, saponins, tannins and terpenoids were present in extracts of both plants while Anthraquinones, glycosides and steroids existed only in A. aspera. This study concludes that A. aspera and T. minuta have remarkable antibacterial and allelopathic activities. There is therefore need to balance between controlling these plants which grow as weeds and maintaining them aimed at utilization for the development of newer antimicrobials and/or bio-control agents. Wed, 01 Jan 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2536 2025-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2534 IMPACT OF PARASITOLOGICAL, CLINICAL AND RENAL-HEPATIC BIOMARKER RESPONSES IN CHILDREN BELOW FIVE-YEAR OLD COINFECTED WITH MALARIA AND HIV IN WESTERN KENYA ARAMBE, MAMBO FIDELIS Malaria and HIV remain major causes of morbidity and mortality among children under five years in sub-Saharan Africa. Their co-infection presents a compounded health challenge, particularly in Western Kenya where Plasmodium falciparum transmission and HIV prevalence are both high. This study aimed to determine the burden of parasitemia and host biomarker responses in children aged below five years co-infected with P. falciparum and HIV. A cross-sectional case-control study involving 138 children aged 6–59 months was conducted at Kakamega County General Teaching and Referral Hospital. Parasitological diagnosis was done by microscopy and rapid diagnostic tests, while biochemical assays evaluated renal and hepatic function. Children co-infected with malaria and HIV were generally younger than those with HIV mono-infection, suggesting that mother-to-child acquired HIV predisposes to increased malaria susceptibility and severity in early life. The co-infected group had significantly higher median parasitemia (1,870 parasites/µL; range: 1,806–80,025), indicating intense transmission. Female children were more affected than males, suggesting possible gender-based differences in exposure, careseeking behavior, or immune response. Renal markers serum creatinine, urea, and blood urea nitrogen were significantly elevated in the co-infected group, reflecting early renal impairment likely linked to immune complex deposition and microvascular obstruction. Hepatic markers ALT, AST, GGT, total and direct bilirubin were also markedly raised, indicating hepatocellular injury and cholestasis. Total protein, albumin, and globulins were significantly higher in co-infected children, suggesting polyclonal B-cell activation and hypergammaglobulinemia driven by chronic immune stimulation. Among the biochemical markers, LDH, creatinine, and ALP exhibited high sensitivity and specificity in predicting organ dysfunction, while GGT, bilirubin, and total protein demonstrated high sensitivity but lower specificity. Receiver Operating Characteristic (ROC) analyses showed modest predictive value (AUC 0.43–0.69) for these markers in identifying renal and hepatic dysfunction. The findings suggest that combining hepatic and renal markers could enhance diagnostic accuracy in co-infected children. P. falciparum and HIV co-infection in children under five years significantly disrupts renal and hepatic function, reflecting compounded immune and metabolic stress. Elevated creatinine, bilirubin, and transaminases indicate potential for these markers to serve as adjunct diagnostic and prognostic tools in endemic areas. The study underscores the need to integrate biochemical assessment into pediatric malaria management, especially in HIV-prevalent regions. Routine monitoring of renal and hepatic function is recommended for timely identification of co-infected children at risk of severe outcomes. Further longitudinal and multi-center studies should investigate the mechanistic pathways underlying biomarker alterations and validate context-specific diagnostic thresholds for clinical use. Wed, 01 Jan 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2534 2025-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2523 CHARACTERIZATION OF CASSAVA (Manihot esculenta Crantz) GERMPLASM IN KENYA NYAMWAMU, CHARLES NYARANG’O Cassava (Manihot esculenta Crantz) is a crucial income crop and staple food crop, providing substantial carbohydrates for millions globally and supporting small-scale farmers in Kenya. Due to incorrect characterization of the phenotypic and genetic materials available, the gene pool for cassava in Kenya are frequently overestimated or underestimated. Therefore, this study sought to characterize cassava germplasm in Kenya. Specific objectives were to; characterize and delimit cassava germplasm based on their phenotypic traits, investigate the genetic diversity among the cassava germplasm using molecular markers and also to determine the cyanide concentration levels in leaves, peels and pulp among cassava germplasm in Kenya. A total of 131 cassava accessions were collected from 7 major purposefully selected cassava growing Counties in Kenya. Each cassava accession was represented by a single plant. This plant was divided into 3- 10 pieces and planted in single rows. Plants from this main plot were collected and planted in three sites. In each plot, three rows of five plants were planted. Data collection on phenotypic traits was done at 3, 6, 9 and 12 months. Twenty-one qualitative and four quantitative phenotypic data were collected and subjected to multivariate analysis. At a statistical significance of p≤0.05, the data was subjected to cluster analysis and dendogram construction. From the main plot, apical leaf samples from 40 proportionately sampled accessions were taken for evaluation of genetic diversity and population structure using start-codon-targeted (SCoT) molecular markers. Cluster analysis and dendogram development was done to establish the accessions' genetic variability. A total of 32 samples were processed for cyanide content analysis using picrate paper and spectrophotometric methods. In a field survey, 32 cassava sample accessions were randomly collected from various farms in Migori County for cyanide determination. Phenotypically, a dendrogram generated categorized these accessions into four clusters with Cluster 1, 2, 3 and 4 containing 72.5%, 16.0%, 3.1%, and 8.4% of the genotypes, respectively. Out of the 25 phenotypic traits assessed, 11 principal components accounted for 71.58% of the genetic variation. A total of 119 fragments were amplified, with 89.9% being polymorphic, indicating moderate genetic diversity. The dendrogram grouped the accessions into two clusters at a 0.35 genetic similarity coefficient. Moderate genetic variation among the accessions was revealed by SCoT markers. The study also revealed significant variations in cyanide levels across different cassava parts and accessions. The spectrophotometric method recorded average cyanide levels of 5.89 mg/L, 7.42 mg/L and 8.20 mg/L in leaves, peels and pulps respectively while the picrate paper method showed 3.13 mg/L, 5.44 mg/L, and 7.97 mg/L. The highest cyanide concentration was found in Nyarkadera leaves (26.93 mg/L), Kazanzwara peels (17.82 mg/L) and Nyatanga pulps (26.93 mg/L). The lowest levels were in Nyatanga-002, Nyakanyamkago, and Kasukali leaves (0.40 mg/L), Kasukali peels (1.19 mg/L) and Mzungu pulps (0.40 mg/L). Moderate positive correlations (r=0.547 and r=0.570) between cyanide concentrations in leaves and peels, and a strong positive correlation (r=0.936) in pulps was established. Thus, cassava germplasm in Kenya exhibits moderate diversity, with molecular data revealing clearer differentiation among this germplasm. In addition, the germplasm shows significant cyanide variation necessitating integrated genetic and biochemical breeding approaches. Thus, these results may assist breeders and farmers in optimizing cassava germplasm utilization, ultimately contributing to food security. Wed, 01 Jan 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2523 2025-01-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2514 ANTIDIABETIC ACTIVITY OF LEAVES AND ROOT EXTRACTS OF KENYAN POPULATIONS OF DODONAEA VISCOSA ON STREPTOZOTOCIN (STZ) INDUCED DIABETIC RATS Langa, Philemon Kibet; Njenga, Elizabeth Wanjiku; Jeruto, Pascaline; Lukhoba, Catherine Diabetes is a metabolic disorder affecting more than 400 million people worldwide. There are three types of diabetes which includes type I diabetes mellitus (T1D), type II diabetes mellitus (T2D) and gestational diabetes. The disease is associated with polyuria, polydipsia, and glycosuria, and many other underlying conditions. It leads to disability, high financial constraints and ultimately death of the patients. This study therefore intends to seek alternative ways of managing diabetes using herbal remedies. Dodonaea viscosa leaves and roots were collected from Baringo, Elgeyo Marakwet, Uasin Gishu and Kwale counties. They were soaked in ethanol and their antidiabetic activity done on male swiss albino rats. Antidiabetic activity was calculated by a glucometer. T-test was used to compare the activity of the roots and leaves. ANOVA was calculated using F-test to find out the activity of various populations. A comparison of activity of Insulin, 200 mg and 400 mg/kg bw extracts was determined using their means. From the results, D. viscosa has a strong antidiabetic activity. T-test revealed that there was no significant difference between their activities of roots and leaves as evidenced from p >0.05. Fstatistic (F = 0.545) indicates that the variances between the populations are not statistically different. The p-value (Sig. = 0.742) further confirms this. Insulin led to the highest decrease in blood sugar, followed by plant extract at 400 mg/kg bw and finally 200 mg/kg bw extracts. More research to isolate pure compounds from this rich plant need to be done. Sun, 01 Sep 2024 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2514 2024-09-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2513 Molecular phylogeny and genetic diversity of Dodonaea viscosa populations from North Rift and Coastal Kenya using ITS1 and rbcL markers Langat, P.K.; Njenga, E.W.; Jeruto, P.; Lukhoba, C. W.; Musila, F.M. The genus Dodonaea (Sapindaceae) comprises slightly over 70 species. Dodonaea viscosa is a plant of Australian origin with seven subspecies. In Kenya, there are two subspecies. D. viscosa has been used medicinally to manage several ailments. It is considered a difficult taxonomic group due to its polymorphic nature. Owing to its uses in ethnomedicine and the taxonomic challenge of Kenyan subspecies, a molecular phylogenetic study was done using ITS1 and rbcL genes from Kenyan populations. DNA was extracted, sequenced, exported to MEGA 11, PhyloSuite, and R for analysis. Aligned sequences were subjected to evolutionary analyses and PCA while phylogeny was constructed using maximum likelihood (ML) method. Nucleotide frequency and substitution rates, nucleotide disparity index, and evolutionary divergence of the genes were very low implying a short genetic distance among the Kenyan populations. ML trees showed that the highland and coastal Dodonaea populations were closely related as they are monophyletic and have high bootstrap values. PCA showed that rbcL genes contributed to most variations in Dodonaea populations where two clusters based on rbcL genes were observed. In contrast, ITS1 genes contributed to fewer variations and grouped all Dodonaea populations into one cluster. This study provides more data to solve the taxonomic challenge of D. viscosa. There is a need for further studies targeting other gene regions to understand well the phylogenetic relationships of Kenyan populations of Dodonaea. Tue, 01 Apr 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2513 2025-04-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2512 olecular Analyses of Genetic Variation and Phylogenetic Relationship in the Family Sapindaceae. A Review Paper Langat, P.K.; Njenga, E.W.; Jeruto, P.; Nyamwamu, C.N.; Lukhoba, C.W.; Musila, F.M. The Sapindaceae, commonly known as the soapberry family, is a cosmopolitan group of approximately 1900 species across 144 genera, forming part of the economically and ecologically significant angiosperm order Sapindales. Despite prior taxonomic efforts, relationships within Sapindaceae and across Sapindales have remained poorly resolved due to complex morphological variation and incomplete infra-familial classification systems. Recent advances in molecular systematics, particularly the use of nuclear ribosomal DNA internal transcribed spacer (ITS) sequences and Angiosperms353 target enrichment datasets, have enabled substantial progress in reconstructing evolutionary relationships within this group. ITS-based phylogenetic analyses have confirmed species-level resolution within Indian Sapindus, clearly distinguishing S. emarginatus from S. trifoliatus, and revealing the divergent position of S. oligophyllus, which clusters with Allophylus of tribe Thouinieae. Estimates of evolutionary divergence revealed significant variability among tribes, with the greatest divergence observed between Paullinieae and Harpullieae (0.20) and the least between Sapindeae and Lepisantheae (0.06), supporting past taxonomic hypotheses. Complementary phylogenomic analyses using Angiosperms353 markers across 123 Sapindaceae genera (86% coverage) recovered 21 clades, providing the basis for a revised classification into four subfamilies and 20 tribes, including six newly proposed tribes within Sapindoideae. Broader Sapindales-wide analyses comprising 448 samples and 85% of genera confirmed family monophyly and resolved core clades while also revealing persistent challenges in subfamily-level relationships due to paralogy, likely linked to ancient hybridisation and polyploidy events. The presence of paralogous loci, particularly in Meliaceae and Rutaceae, affirms the need for careful data curation and highlights the impact of ancient genome duplications on phylogenetic inference. This integrated molecular framework provides the most comprehensive phylogenetic resolution of Sapindaceae and Sapindales to date. It offers a robust foundation for future evolutionary, biogeographic, taxonomic, and conservation-orientated studies while emphasising the need for continued sampling and the incorporation of genomic complexity in phylogenetic reconstruction. Fri, 01 Aug 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2512 2025-08-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2495 Screening advanced potato mutant genotypes against bacterial wilt disease under different agro-ecological zones of Kenya Apondi, Maurine; Kinyua, Miriam G.; Were, Javan O.; Gohole, Linnet S. Host plant resistance is a key tool in the management of plant diseases. Mutant lines (IP1, IP2, IP3 and IP4) were tested against other potato varieties (Shangi, Sherehekea, K. Mpya and Unica) in different agro-ecological zones to ascertain their performance under potato bacterial wilt disease pressures. An experiment was set in an RCBD design with three replications in four different sites, namely, Nyandarua, Elgeiyo Marakwet, Burnt Forest and Moiben. Assessment was done on potato bacterial wilt disease prevalence and severities, as well as host plant status, which were rated on a scale of 1-5. Data obtained were subjected to analysis using statistical software GenStat 16th Edition VSN International Ltd. Different response levels and uniqueness were express across all AEZs, where variety, sites and time intervals (DAS) as well as their interactions had significant effects on disease severity, with different tolerance levels to the pathogen experienced in all the lines. The severity mean of four mutant lines was below 2.0 as per the days after sowing (DAS). Moreover, IP1 (2.0) and IP2 (2.1) had an overall mean across all sites; therefore, they proved a high level of tolerance to the bacterial wilt pathogen, while IP3 (2.4) and IP4 (2.5) wer the resistant check (2.8) across all the sites and the susceptible check Kenya Mpya (3.2). Hence, there is a need for regular screening of the available genotypes for R. solanacearum production. The existence of the most tolerant varieties could form a baseline in integrated disease management for sustainable potato production. Sun, 01 Jun 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2495 2025-06-01T00:00:00Z http://41.89.164.27:8080/xmlui/handle/123456789/2493 Investigation of the morphological variation among taxa to determine species diversity within Cyperus dives complex in East Africa Tallam, Tallam; Otieno, Donald Fredrick; Musil, Paul Mutuku The Cyperus dives complex, a group within the Cyperaceae family, exhibits substantial morphological diversity across East Africa, presenting a valuable opportunity for studying species diversity and ecological adaptation. This investigation explored the morphological variation among taxa within this complex to assess species diversity and inform conservation strategies. Through a detailed examination of leaf shape, inflorescence structure, and reproductive features, the study reveals significant variations that delineate species boundaries and highlight adaptive traits. Findings from existing literature affirms the complex interplay between environmental factors and morphological characteristics, illustrating how different taxa are adapted to a range of ecological niches. The results demonstrates that morphological diversity within the Cyperus dives complex is influenced by habitat variability and evolutionary pressures. The study concludes that a comprehensive understanding of morphological variation is essential for accurate species identification and effective conservation management. This investigation contributes to the broader understanding of biodiversity in East Africa and supports the development of targeted conservation strategies to protect the diverse taxa within the Cyperus dives complex. Tue, 01 Apr 2025 00:00:00 GMT http://41.89.164.27:8080/xmlui/handle/123456789/2493 2025-04-01T00:00:00Z