RP-Department of Plant and Microbial Sciences

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Geographical and Linguistic Structure in the People of Kenya Demonstrated Using 21 Autosomal STRS
(Elsevier B.V, 2021-05) Muinde, Jane Mbithe; Bhanu, Devi R. Chandra; Neumann, Rita; Oduor, Richard Okoth; Kanja, Wangu; Kimani, Joseph Kagunda; Mutugi, Marion W.; Smith, Lisa; Jobling, Mark A.; Wetton, Jon H.
Kenya is a diverse and populous nation that employs DNA evidence in its criminal justice system, and therefore requires reliable information on autosomal STR allele frequency variation across the country and in its many ethnic groups. In order to provide reference data and to assess population structure, we analysed the 21 autosomal STRs in the GlobalFiler multiplex in a sample of 510 indigenous Kenyans representing the country’s eight former provinces, 43 of its 47 counties, three main linguistic families and all 29 ethnic groups that each comprise >0.5% of the 2019 census population. The indigenous population originated from successive migrations of Cushitic, Nilotic and Bantu speaking groups who settled in regions that suited their distinctive sustenance lifestyles. Consequently, they now largely reside in a patchwork of communities with strong associations with particular counties and provinces and limited degrees of inter-group marriage, as shown by DNA donors’ ancestry details. We found significant genetic differentiation between the three Nilotic language sub-families, with Western Nilotes (the Luo ethnic group) showing greater similarity to the Bantu than the Southern and Eastern Nilotes which themselves showed closer affinity to the Cushitic speakers. This concurs with previous genetic, linguistic and social studies. Comparisons with other African populations also showed that linguistic affiliation is a stronger factor than geography. This study revealed several rare off-ladder alleles whose structure was determined by Sanger sequencing. Among the unusual features that could affect profile interpretation were a deletion of Amelogenin Y but no other forensic marker (autosomal or Y-chromosomal), a triallelic pattern at TPOX and an extremely short SE33 allele falling within the expected size range of D7S820. Compared with the currently implemented Identifiler multiplex, Random Match Probabilities decreased from 6.4 × 10–19 to 3.9 × 10–27. The appreciation of local population structure provided by the geographically and ethnically representative sample in this study highlights the structured genetic landscape of Kenya
Somatic Embryogenesis and Plant Regeneration of Farmer-Preferred Passion Fruit Varieties Grown in Kenya
(mdip, 2023-12) Asande, Lydia K.; Omwoyo, Richard O.; Oduor, Richard O.; Nyaboga, Evans N.
In vitro regeneration of passion fruit has great prospects for mass production of diseasefree planting materials. The objective of this study was to develop an in vitro regeneration system through somatic embryogenesis for farmer-preferred genotypes grown in Kenya. Callus induction and somatic embryogenesis were carried out using leaf and immature seed explants. The explants were cultured on Murashige and Skoog medium augmented with different concentrations of 2,4- dichlorophenoxyacetic acid (2,4-D) alone and 2,4-D combined with 1.0 mg L−1 thidiazuron (TDZ). Data were recorded and subjected to analysis of variance. The highest number of somatic embryos was obtained from KPF4 genotype using MS medium supplemented with 8 mg L−1 2,4-D and 1 mg L−1 TDZ. The embryos were converted to plants on germination medium comprising of MS augmented with 0.5 mg L−1 6-benzyl amino purine (BAP). The plantlets were hardened for 4 weeks in plastic pots. The survival rate during hardening of in vitro regenerated plants was 77.8%. The present study reports a regeneration system through somatic embryogenesis for KPF4 passion fruit grown in Kenya. The in vitro regeneration system can be utilized for mass propagation and genetic improvement of KPF4 variety grown in Kenya.
Cassava (Manihot Esculenta) Dual Use for Food and Bioenergy: A Review
(WILEY, 2021) Fathima, Anwar Aliya; Sanitha, Mary; Tripathi, Leena; Muiruri, Samwel
Cassava (Manihot esculenta. Crantz) is a starch-rich, woody tuberous, root crop important for food, with little being done to investigate its potential as a bioenergy crop despite its enormous potential. The major bottleneck in the crop being able to serve this dual role is the competition of its storage roots for both purposes. The major cassava production regions primarily use the tuberous roots for food, and this has resulted in its neglect as a bioenergy crop. The use of non-food cassava parts as a feedstock in cellulosic biofuel production is a promising strategy that can overcome this challenge. However, in non-tuber parts, most of the sugars are highly sequestered in lignin complexes making them inaccessible to bacterial bioconversion. Additionally, cassava production in these major growing areas is not optimal owing to several production constraints. The challenges affecting cassava production as a food and bioenergy crop are interconnected and therefore need to be addressed together. Cassava improvement against biotic and abiotic stresses can enhance productivity and cater for the high demand of the roots for food and bioenergy production. Furthermore, increased production will enhance the usability of non-food parts for bioenergy as the bigger goal. This review addresses efforts in cassava improvement against stresses that reduce its productivity as well as strategies that enhance biomass production, both important for food and bioenergy. Additionally, prospective strategies that could ease bioconversion of cassava for enhanced bioenergy production are explored.
Salinity and Sodicity Induced Responses on Total Phenols, Flavonoids and Tannins Accumulation on Cowpea (Vigna unguiculata (L) Walp)
(AJHS, 2023-09) Mutuku, T; Mamati, E; Mutune, A.
Food shortage remains a developmental hindrance in globally with about 25% of world’s population suffering from continued food and nutritional insecurity especially in ASALs. Reduced arable tracts of land for cultivation, increased population and variation in nonliving factors such as water and salinity are challenges facing the world. Cowpea is commonly grown on ASALs which are greatly affected by salinity. The study involved 4 cowpea varieties; K80, M66, Kunde 1 and KVU 27-1 that were subjected to both CaCl2(aq) and NaCl(aq) at levels of 0 (control), four, eight and twelve dS/m. A complete randomizeddesign in replicates of three in a greenhouse was usedat Jomo Kenyatta University of Science and Technology, JujaSubcounty, Kiambu County on October 2021- January 2022.The salts concentrations (NaCl and CaCl2) were applied to the soil from time of sowing and constant levels were monitored throughout by use of an EC probe Determination of total phenols, tannins, and flavonoids content was done using a UV-VIS spectrophotometer. The obtained data wereevaluated using 2-way ANOVAat 5% significance level using SPSS (software version 21). As salinity and sodicitylevels increased, the phenols, tannins and flavonoids content also increased. Variety M66 recorded the highest total phenols, tannins and flavonoids above 8 dS/m hence it developed a defense mechanism against salt stress. Therefore, variety M66 was better adapted to high salt levels because it performed better at high saline and sodic levels. Therefore, farmers especially in marginal areas affected by salinity should adopt growing of M66 cowpea variety.
Profiles of Bacterial Communities and Environmental Factors Associated with Proliferation of Malaria Vector Mosquitoes within the Kenyan Coast
(Microbiology Society, 2023) Mutinda, Josphat; Mwamburi, Samuel Mwakisha; Oduor, Kennedy Omondi; Omolo, Maurice Vincent; Ntabo, Regina Mongina; Gathiru, James Muhunyu; Mwangangi, Joseph; Nonoh, James O. M.
Background. Since Anopheles mosquitoes which transmit and maintain the malaria parasite breed in the outdoor environment, there is an urgent need to manage these mosquito breeding sites. In order to elaborate more on the ecological landscape of mosquito breeding sites, the bacterial community structure and their interactions with physicochemical factors in mosquito larval habitats was characterised in Kwale County (Kenya), where malaria is endemic. Methods. The physical characteristics and water physicochemical parameters of the habitats were determined and recorded. Water samples were also collected from the identified sites for total metagenomic DNA extraction in order to characterise the bacterial communities within the breeding sites. Results and Discussion. Sites where mosquito larvae were found were described as positive and those without mosquito larvae as negative. Electrical conductivity, total dissolved solids, salinity and ammonia were lower in the rainy season than in the dry season, which also coincided with a high proportion of positive sites. Pseudomonadota was the most common phyla recovered in all samples followed by Bacteroidota and then Actinomycetota. The presence or absence of mosquito larvae in a potential proliferation site was not related to the bacterial community structure in the sampled sites, but was positively correlated with bacterial richness and evenness. Conclusion. Generally, the presence of Anopheles mosquito larvae was found to be positively correlated with rainy season, bacterial richness and evenness, and negatively correlated with electrical conductivity, total dissolved solids, salinity and ammonia. The findings of this study have implications for predicting the potential of environmental water samples to become mosquito proliferation sites.
Effects of Anthracnose Disease on Avocado Production in Kenya
(Tylor and Francis, 2020) Kimaru, K. S; Muchemi, K. P; Mwangi, J. W
Avocado production has increased exponentially over the years worldwide. This has been necessitated by the various uses of avocado fruits other than as a source of nutrients which includes pharmaceutical, cosmetic and oil industries. These various uses of avocado have resulted to improved livelihood in terms of income generation. Increased avocado production worldwide has been at the expense of other tree and food crops. In Kenya, it is attributed to decreased acreage of key cash crops such as coffee and tea as well as staple food crops such as maize and beans. Avocado production, however, has been faced by several constraints such as poor rootstalks, diseases, pests, abiotic factors, poor harvesting technology, poor handling of harvested fruits and post-harvest diseases. All these challenges lead to poor fruit quality at the market both local and export market leading to losses economically. Of major concern is anthracnose disease caused by Colletotrichum gloeosporioides, Colletotrichum boninense, Pestalotiopsis microspora both in the field and after harvest. The disease is associated with 60% losses as a result of abortion of fruits in the field and post-harvest rots. Limited studies on the the interaction of the causal agents, the disease cycle and its epidemiology in Kenya, has rendered disease management impractical. Control of this disease has been through pruning and sorting of the diseased fruits. However, majority of the farmers do not apply any control measures. Furthermore, the use of chemical control has been limited due to a lack of available fungicides registered for use in Kenya. Fruit rots and quality issues due to black spots has affected the marketability of avocado fruits in the export market mainly EU market. Due to this, the avocado farmer in Kenya has been receiving low returns from their avocado export. Further understanding of the anthracnose disease epidemiology, virulence and genetic variation of the causal agent and the sensitivity of the causal agent to available fungicides will enhance the effectiveness of the anthracnose disease management, resulting in improved avocado productivity
Factors Influencing Tomato Post-harvest Losses in Mwea, Kenya
(IJMRGE, 2023) Mugao, Lydia G.
Tomato is an important vegetable crop in Kenya which is widely grown for home consumption and commercial purposes. However, the crop is faced with a number of challenges including post-harvest losses which is a major threat to harvested produce. Presence of losses in a crop indicates wastage of resources that were put in place during production. Periodic surveys are necessary to help understand the severity and causes of losses in a specific place at a specific time. The aim of this study was to survey on the severity and causes of tomato postharvest losses in Mwea, Kenya. During the survey, sixty-eight farmers were randomly selected and interviewed using structured questionnaire and factors influencing tomato postharvest losses documented. Descriptive statistics was used to analyze the information collected from the respondents. Results showed that the most common varieties grown by farmers at the time of survey were Kilele F1and Roma V.F (80.0% and 10.0% respectively). Factors influencing tomato postharvest losses were; poor means of transport (10.63%), and time lag in the market. The common pests that were found attacking tomato fruits were; American bollworms (68.5%), birds (1.2%), spider mites (19.8%), and thrips (8.1%). The most common diseases were; Fusarium rot (45.3%), Bacterial soft rot (50%), and Phoma rot (4.7%). The average losses estimated from the study was 72.0%. The study recommended that the farmers should avail themselves to seminars on fruit handling during harvesting and transport and the new tomato varieties that are resistant to pests and diseases and with good keeping quality.
Mapping Potential Anopheles Gambiae S.L. Larval Distribution Using Remotely Sensed Climatic and Environmental Variables in Baringo, Kenya
(Wiley Online Library, 2018) Olagoo, D.O; Oriaso, S.O; Nyamongo, I.K; Estambale, B.BA
. Anopheles gambiae s.l. (Diptera: Culicidae) is responsible for the transmission of the devastating Plasmodium falciparum (Haemosporida: Plasmodiidae) strain of malaria in Africa. This study investigated the relationship between climate and environmental conditions and An. gambiae s.l. larvae abundance and modelled the larval distribution of this species in Baringo County, Kenya. Mosquito larvae were collected using a 350-mL dipper and a pipette once per month from December 2015 to December 2016. A random forest algorithm was used to generate vegetation cover classes. A negative binomial regression was used to model the association between remotely sensed climate (rainfall and temperature) and environmental (vegetation cover, vegetation health, topographic wetness and slope) factors and An. gambiae s.l. for December 2015. Anopheles gambiae s.l. was significantly more frequent in the riverine zone (P<0.05, r =0.59) compared with the lowland zone. Rainfall (b=6.22, P<0.001), slope (b= −4.81, P=0.012) and vegetation health (b= −5.60, P=0.038) significantly influenced the distribution of An. gambiae s.l. larvae. High An. gambiae s.l. abundance was associated with cropland and wetland environments. Effective malaria control will require zone-specific interventions such as a focused dry season vector control strategy in the riverine zone
Sensitivity of Vegetation to Climate Variability and Its Implications for Malaria Risk in Baringo, Kenya
(Public Library of Science San Francisco, CA USA, 2018) Amadi, Jacinter A; Olago, Daniel O; Ong’amo, George O; Oriaso, Silas O; Nanyingi, Mark; Nyamongo, Isaac K; Estambale, Benson B. A
The global increase in vector borne diseases has been linked to climate change. Seasonal vegetation changes are known to influence disease vector population. However, the relationship is more theoretical than quantitatively defined. There is a growing demand for understanding and prediction of climate sensitive vector borne disease risks especially in regions where meteorological data are lacking. This study aimed at analyzing and quantitatively assessing the seasonal and year-to-year association between climatic factors (rainfall and temperature) and vegetation cover, and its implications for malaria risks in Baringo County, Kenya. Remotely sensed temperature, rainfall, and vegetation data for the period 2004–2015 were used. Poisson regression was used to model the association between malaria cases and climatic and environmental factors for the period 2009–2012, this being the period for which all datasets overlapped. A strong positive relationship was observed between the Normalized Difference Vegetation Index (NDVI) and monthly total precipitation. There was a strong negative relationship between NDVI and minimum temperature. The total monthly rainfall (between 94 -181mm), average monthly minimum temperatures (between 16–21˚C) and mean monthly NDVI values lower than 0.35 were significantly associated with malaria incidence rates. Results suggests that a combination of climatic and vegetation greenness thresholds need to be met for malaria incidence to be significantly increased in the county. Planning for malaria control can therefore be enhanced by incorporating these factors in malaria risk mapping.
“We Don’t Want Our Clothes to Smell Smoke”: Changing Malaria Control Practices and Opportunities for Integrated Community-Based Management in Baringo, Kenya
(Springer, 2018) Amadi, Jacinter A; Olago, Daniel O; Ong’amo, George O; Oriaso, Silas O; Nyamongo, Isaac K; Estambale, Benson B. A
Background: The decline in global malaria cases is attributed to intensified utilization of primary vector control interventions and artemisinin-based combination therapies (ACTs). These strategies are inadequate in many rural areas, thus adopting locally appropriate integrated malaria control strategies is imperative in these heterogeneous settings. This study aimed at investigating trends and local knowledge on malaria and to develop a framework for malaria control for communities in Baringo, Kenya. Methods: Clinical malaria cases obtained from four health facilities in the riverine and lowland zones were used to analyse malaria trends for the 2005–2014 period. A mixed method approach integrating eight focus group discussions, 12 key informant interviews, 300 survey questionnaires and two stakeholders’ consultative forums were used to assess local knowledge on malaria risk and develop a framework for malaria reduction. Results: Malaria cases increased significantly during the 2005–2014 period (tau = 0.352; p < 0.001) in the riverine zone. March, April, May, June and October showed significant increases compared to other months. Misconceptions about the cause and mode of malaria transmission existed. Gender-segregated outdoor occupation such as social drinking, farm activities, herding, and circumcision events increased the risk of mosquito bites. A positive relationship occurred between education level and opinion on exposure to malaria risk after dusk (χ 2 = 2.70, p < 0.05). There was over-reliance on bed nets, yet only 68% (204/300) of respondents owned at least one net. Complementary malaria control measures were under-utilized, with 90% of respondents denying having used either sprays, repellents or burnt cow dung or plant leaves over the last one year before the study was conducted. Baraza, radios, and mobile phone messages were identified as effective media for malaria information exchange. Supplementary strategies identified included unblocking canals, clearing Prosopis bushes, and use of community volunteers and school clubs to promote social behaviour change. Conclusions: The knowledge gap on malaria transmission should be addressed to minimize the impacts and enhance uptake of appropriate malaria management mechanisms. Implementing community-based framework can support significant reductions in malaria prevalence by minimizing both indoor and outdoor malaria transmissions
Trends in Forest Condition, Threats and Conservation Action as Derived from Participatory Monitoring in Coastal Kenya
(Wiley Online Library, 2016) Ndang’ang’a, Paul K; Barasa, Fred M; Kariuki, Mercy N; Muoria, Paul
The coastal forests of Kenya are conservation priorities hosting high levels of biodiversity. Monitoring of biodiversity in these forests is therefore necessary to understand and reverse negative trends in good time. Using the Important Bird Area (IBA) monitoring framework, a participatory approach, state (habitat condition), pressure (threats) and response (conservation action) indicators of twelve coastal Kenya forest IBAs were assessed from 2004 to 2011. Trends for these indicators were assessed at six sites for which sufficient data existed: Arabuko-Sokoke, Dakatcha Woodlands, Gede Ruins, Lower Tana River, Shimba Hills and Taita Hills, and baselines were described for remaining six. Changes were always small, but state deteriorated in Gede, Lower Tana and Shimba Hills, remained the same (unfavourable)inArabuko-Sokoke andDakatcha, andimproved in Taita Hills. Pressure reduced in Arabuko-Sokoke, Dakatcha and Taita Hills, deteriorated in Lower Tana and Shimba Hills and remained the same (medium) in Gede. Response improved in Dakatcha, remained the same (medium) in Shimba Hills, and deteriorated in the rest. As there was an apparent overall deterioration in the forests assessed, improved management of the protected sites and increased conservation action through community engagement around protected areas and within the nonprotected IBAs are recommended. Key words: biodiversity, forest, Kenya, monitoring, participatory R esum e Les for^ets coti ^ eres du Kenya jouissent d’une biodiversit e consid erable qui en fait des priorit es en matiere de conservation. Il est des lors n ecessaire d’assurer le suivi de la biodiversit e dans ces for^ets pour comprendre, voire inverser en temps utile les tendances n egatives. En utilisant le cadre de suivi des Zones importantes pour la conservation des oiseaux (ZICO) qui est une approche participative, les indicateurs d’ etat (conditions de l’habitat), de pression (menaces) et de r eponse (mesure de conservation) ont et e evalu es de 2004 a 2011 pour 12 ZICO de for ^ets coti ^ eres du Kenya. Les tendances de ces indicateurs ont et e evalu ees sur six sites pour lesquels il y avait suffisamment de donn ees: Arabuko-Sokoke, Dakatcha Woodlands, Ruines de Gedi, Lower Tana River, Shimba Hills et Taita Hills, et des bases de r ef erence ont et e d ecrites pour les six autres. Les changements etaient toujours l egers mais l’ etat s’est d et erior e a Gedi, Lower Tana et Shimba Hills, il est rest e le m^eme (d efavorable) a Arabuko-Sokoke et a Dakatcha et il s’est am elior e a Taita Hills. La pression s’est r eduite a Arabuko- Sokoke, Dakatcha et Taita Hills, s’est accentu ee a Lower Tana et Shimba Hills et est rest ee stable (moyenne) a Gedi. La r eponse s’est am elior ee a Dakatcha, est rest ee la m^eme (moyenne) dans les Shimba Hills et s’est d et erior ee ailleurs. Etant donn e qu’il semble qu’il y ait une d egradation g en erale dans les for^ets evalu ees, une meilleure gestion des sites prot eg es et de plus fortes mesures de conservation sont recommand ees, gr^ace a l’engagement communautaire autour des aires prot eg ees et au sein des ZICO non prot eg ees.
Behavioral Patterns and Responses to Human Disturbances of Wild Somali Ostriches (Struthiomolybdophanes) In Samburu, Kenya.
(International Journal of Advanced Research, 2016) Mutiga, Maricianoiguna; Muoria, Paul Kimata; Kotut, Kiplagat; Karuri, Hannah Wangari
Somali ostrich has suffered a drastic decline in its population and range mainly due to hunting over the years for meat, skin and feathers. Urgent conservation measures should therefore be taken to reverse this trend particularly in their current population stronghold, the Samburu landscape. In this range, the magnitude and consequences of human disturbance on the ostrich has not been established. The aim of this study was therefore to investigate the behavioural patterns and assess the impacts of human disturbance to the bird. Focal animal sampling was used to establish ostrich‟s behavioural activity budget while the magnitude of human disturbance was assessed by determining and comparing flight initiation distances in the protected and partially protected areas. Somali ostrich spent most of their diurnal time in feeding and moving, and are more sensitive to human disturbance in the protected areas than they are in the partially protected areas. The results of this study imply that the ratite does not differ in behavioural patterns from other extant ostrich species and human disturbance is not posing a significant threat to its survival within Samburu landscape. Further studies are recommended for better understanding of the conservation status of the newly published species.
Valuation of Harvested Goods in Mida Creek with Application of the TESSA Approach
(Western Indian Ocean Marine Science Association (WIOMSA), 2020) Olima, Cecilia O; Muoria, Paul K; Owuor, Margaret A
Mangroves are considered a highly productive blue forests resource providing services that are important to the community both locally and globally. In recent times there has been an increase in studies on valuation of ecosystem services provided by mangroves. However, there is need to provide a simplified approach to identify, assess and quantify ecosystem services. In this study the Toolkit for Ecosystem Services Site-based Assessment (TESSA) was used to assess the value of harvested goods provided by the mangroves of Mida Creek in the current state and under plausible alternative scenarios. Spatial methods (GIS) were used to collect data for the period 1985-2019, and household interviews were used to collect data on harvested goods. Descriptive statistics were used to summarize quantitative data. Results show that the estimated current annual value of harvested goods in Mida Creek is US$ 11.2 million. This value increased to US$ 14.3 million under the conservation scenario and reduced to US$ 10.9 million under the business as usual scenario (BAU). These findings add to the growing literature on ecosystem service valuation and the need to use site-specific non-modelling tools like TESSA.
Genotyping for Blast (Pyricularia Oryzae) Resistance Genes in F2 Population of Supa Aromatic Rice (Oryza Sativa L.)
(Hindawi, 2019) Kanyange, L; Kamau, J; Ombori, O; Ndayiragije, A; Muthini, M
The ascomycete fungus, Pyricularia oryzae or Magnaporthe oryzae, is known to cause blast disease in more than 80 host plants of the Gramineae family—cereals including rice and grasses. The improvement of the Supa234 rice line (IR97012-27-3-1-1-B, containing badh2 gene for aroma) developed at IRRI-ESA Burundi consisted of introgression of R genes (Pita and Pi9) for blast resistance. The F2 population obtained via the cross had been screened for blast resistance using inoculation with Pyricularia oryzae spore’s suspension. The objectives of this study were to assess the presence of Pita and Pi9 genes for blast resistance and to assess the presence of the badh2 gene for aroma in the screened F2 plants using molecular markers. Genotyping was carried out in 103 F2 plants which grew to maturity using the KASP genotyping method with SNP markers (snpOS0007, snpOS0006, and snpOS0022) targeting the Pita and Pi9 genes for blast resistance and the badh2 gene for aromatic fragrance. The genotyping results showed that 38 F2 plants had the Pita gene present in both alleles, 31 F2 plants with the Pita gene in one allele, and only one plant (3B1) was found with the Pi9 gene in one allele. The badh2 gene for aroma was detected in 27 F2 plants on both alleles and in 57 F2 plants on one allele. There were thirteen plants which had both the Pita gene and the badh2 gene for aroma, and only one plant (3B1) had a combination of the three genes (Pita, Pi9, and badh2). Seven plants resistant to blast disease (2H2, 2H4, 1G2, 1C12, 1E13, 1B12, and 1C5) with the Pita and badh2 genes were found, and only one resistant plant (3B1) had a combination of the three genes Pi9, Pita, and badh2 which is recommended to be bulked for the development of the Supa aromatic rice variety resistant to blast disease. The plants generated by the best line 3B1 should further be evaluated for grain quality (Supa type) after F5 generation in the field.
Analysis of Combining Ability for Early Maturity and Yield in Rice (Genus: Oryza) At the Kenyan Coast
(Hindawi Limited, 2020) Dianga, Al-Imran; Joseph, Kamau W; Musila, Ruth N
(e main challenges facing rain-fed rice farming in Kilifi County at the Kenyan coast are inadequate and erratic rainfall, inadequate skills, and poorly developed infrastructure. Of great importance is erratic rainfall that tends to depress towards the end of long rain season, leading to crop failure. Combining ability analysis is one of the most valuable tools used to ascertain gene action effects and help in selecting desirable parents for making crosses and coming up with high yielding and early maturing lines. Combining ability for early maturity and yield has not been studied at the Kenyan coast. (is study aimed at determining and identifying good, general, and specific combiners for selecting better parents and better cross combinations in rice crops for developing high yield and short duration lines in rain-fed rice farming. Seven lines were subjected to half-diallel mating design at the Kenya Agricultural and Livestock Research Organization (KALRO), Mtwapa, and at Bahari in Kilifi town. Evaluation for general combining ability (GCA) and specific combining ability (SCA) analysis was done. Combining ability variance and GCA and SCA effects were determined. Based on GCA effects, best parent for early maturity was Dourado Precoce, while for yield, Supaa, Komboka, and NERICA 10. SCA estimates indicated that best crosses for yield were D/S, D/N1, and K/N10, while the best performing cross for early maturity was D/N1.
Arbuscular Mycorrhizal Fungi Colonization in the Rhizosphere of Aspilia pruliseta Schweif. ext Schweif in the Semiarid Eastern Kenya
(sage publishers, 2020) Muchoka, James Peter; Mugendi, Daniel Njiru; Njiruh, Paul Nthakanio; Onyari, Charles; Mbugua, Paul Kamau; Njeru, Ezekiel Mugendi
The use of arbuscular mycorrhizal fungi (AMF) to enhance soil phosphate uptake is a biological technique considered to cure phosphate deficiency in soils. This study investigated association of Aspilia pruliseta Schweif shrub with AMF in Kenya. The study aims at profiling a tropical shrub with multiple ecological benefits that could reduce addition of chemical phosphatic fertilizer into the soil and reverse negative consequences of eutrophication. Sampling was purposive to have areas with or without Aspilia pruliseta vegetation growing. A small amount (10 g) of the soil from 27 composite samples was used for spore count determination and a similar amount for next generation sequencing. Spore counts varied significantly among soil textural types, sample locations, and soil depth. Sandy loam had the highest spore counts with a mean average of 404 spores. The spore count decreased significantly (P < .05) with the depth of soil from a mean of 514 spores to 185 along the rhizosphere. The intensity of spore morphotypes was significantly higher at P < .05 for soils whose vegetation was covered with Aspilia pruliseta than those without. Aspilia pruliseta vegetation used together with sandy loam soil could culture commercial mycorrhiza fungi production for use in agrisystems.
Indigenous Use and Commercialization of Urtica dioica l. from Local Communities of Kieni West Sub County, Nyeri County, Kenya
(Fortune Journals, 2023) Kamicha, Joseph Wairimu; Karanja, Rebecca N.; Ngaruiya, Grace W.
Though the stinging nettle (Urtica dioica L.) is categorized globally as an invasive species and nuisance weed due to its stinging trichomes, the plant is a source of vital nutrition and an ingredient in many indigenous medicine practices. Urtica dioica has a dense rhizome that ensures its survival, enduring adverse climatic conditions throughout the year. Hence, this study sought to determine indigenous knowledge on the uses of U. dioica by the local communities in three parts of semi-arid Kieni Sub County namely Endarasha, Charity, and Watuka. Questionnaires were administered to 196 local informants on the diverse indigenous uses of U. dioica. Independent sample t-test showed no significant difference (P>0.05) in the use of U. dioica as a medicinal plant across gender. 100% of the respondents rated U. dioica as among the most consumed vegetable. Thirdly, the study established the use of U. dioica in the food, medicine, and veterinary sector. Lastly, despite prolonged adverse climatic conditions in the Kieni region, there has been a general increasing trend of U. dioica invasiveness over the last 10 years. Such consumption, coupled with the resistance of U. dioica to harsh climatic changes could indicate the future economic potential of the plant species in the local cottage industries to support the government's food production and manufacturing agenda. This study recommends increasing public awareness of the benefits of U. dioica to boost its consumption.
Genetic Variability of Agronomic Traits as Potential Indicators of Drought Tolerance in Common Beans (Phaseolus vulgaris L.)
(hindawi, 2019) Langat, Charles; Ombori, Omwoyo; Leley, Philip; Karanja, David; Cheruiyot, Richard; Gathaara, Moses; Masila, Benard
Sixteen progeny lines of common beans obtained from single crosses made between two parents, GLP2 and KAT B1, were grown in randomized complete block design in a rainout shelter at the Agricultural and Mechanization Research Institute, Machakos, Kenya. 'e experiment was conducted to study inheritance of traits associated with drought stress adaptation and to establish if significant variation for those traits was existing in order to carry out selection for drought tolerance. 'e calculated mean values were used to estimate heritability, genetic advance, and correlation study for each trait. Water stress had a significant (p ≤ 0.01) effect on the number of pods per plant, grains per plant, 100-seed weight, and yield per plant. 'e highest values for genotypic coefficient of variation (36.11%) and phenotypic coefficient of variation (36.70%) were recorded for pods plant-1 under stress condition. Highest broad-sense heritability estimates (96.54%, 94.97%, and 93.16%) coupled with high genetic advance as percent of the mean (22.32%, 34.97%, and 26.32%) were obtained for the number of pods plant− 1, days to maturity, and yield plant− 1, respectively, showing that selection of these traits together could lead to yield improvement under stressed conditions. Harvest index showed a significant and positive relationship with biomass aboveground (r � 0.86) and the number of pods plant− 1 (r � 0.86) indicating the possibility of identifying high performing lines of common beans for drought stress environment for further studies on these traits.
Effects of Conservation Tillage on Maize (Zea Mays L.) and Beans (Phaseolus Vulgaris L.) Chlorophyll, Sugars and Yields in Humic Nitisols Soils of Embu County, Kenya
(African Journal of Agricultural Research, 2019) Munyao, Joseph Kyalo; Gathaara, Moses Hungu; Micheni, Alfred Ngera
An experiment was conducted to determine the effects of conservation tillage (CT) practices on leaf chlorophyll content, sugars and yields of Zea mays L. and Phaseolus vulgaris L. for two consecutive cropping seasons at the Kenya Agricultural and Livestock Research Organization farm in Embu County, Kenya. The experimental design was a Randomized Complete Block Design with 9 treatments replicated 3 times. The treatments were, conventional tillage sole maize, zero tillage sole maize, Furrows/Ridges sole maize, conventional tillage sole bean, zero tillage sole bean, furrows and ridges sole bean, conventional tillage maize-bean intercrop, zero tillage maize-bean intercrop, furrows/ridges maize-bean intercrop. Zea mays L. and Phaseolus vulgaris L. plants grown under the CT plots had significantly more chlorophyll content, more sugar content and more grain weight than those under conventional tillage practices (CVT). The results provided a physiological basis for the observed increase in yields. They led to a conclusion that the CT method is suitable for improving crop productivity through enhancing physiological functions in the leaf.
Ecological Ethics and Community Engagement Approach to Ecosystems Conservation: A Case Study of Volcanoes National Park in Rwanda
(science publishing group, 2022) Wanyera, Francis; Mutugi, Chira Robert; Najma, Dharani; Gichuki, Nathaniel
Ecosystems can only be preserved if there is an inter-link of ethics in conservation. An assortment of literature exists that encompasses ecological ethics which at times is also referred to as ecological integrity that involves the ethics of research as well as environmental ethics. The study set out to investigate how ecological ethics interlinks with conservation of the ecosystems or environment. The challenge was that ecological ethics implementation together with local community engagement were not strong which negatively affected the ecosystem conservation. The study was guided by three specific objectives that included; i) to investigate the trends in key policies linked to ecological ethics and ecosystem conservation in VNP; ii) to ascertain the impact of ecological ethics on ecosystem conservation in VNP; iii) to determine the benefits of engaging the local community in ecological ethics approach to ecosystem conservation. The literature focused on environmental ethics, policies linked to ethics and local community engagement. Under the methodology section the study used the descriptive research design and purposive sampling technique. The population of study was 52 households while the sample was 42 households living within 200 meters from the park boundary. The findings showed that ecological ethics were crucial in influencing how humans conserved the ecosystems. Further, the study findings found out that there were challenges encountered especially when lack of awareness of ecological ethics among the local community and less engagement affected ecosystem conservation. However, the findings also indicated that as much as there were challenges, on the hand ecological ethics if well embraced, can generate a number of benefits both for the park and local community. In conclusion, conservation cannot be successful without incorporating the ecological ethics. It was recommended that VNP should engage all the stakeholders in ecological ethics particularly in line with conservation to achieve sustainable ecosystem conservation.

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