Browsing by Author "Waturu, C.N."
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Item Diversity and Population Structure of Local and Exotic Lablab Purpureus Accessions in Kenya as Revealed by Microsatellite Markers(eSciPub LLC, 2021) Kamau, E.M.; Kinyua, M.G.; Waturu, C.N.; Kiplagat, O.; Wanjala, B.W.; Kariba, R.K.; Karanja, D.R.; Kenya Agriculture and Livestock Research Organization ; University of Eldoret ; World AgroforestryLablab purpureus is an important pulse crop in some parts of sub-Saharan Africa and Asia but has largely remained underuti-lized. Understanding the genetic diversity is prerequisite for ge-netic improvement and utilization of this leguminous crop. The relationships of the local lablab genotypes and those collected from other diverse geographic origins including the wild acces-sions remain unknown in Kenya. The study was undertaken to determine genetic diversity and population structure of germ-plasm accessions collected from Kenya and other global regions. Eight simple sequence repeat primer pairs were used to genotype the 189 lablab accessions. A total of 39 alleles were re-vealed by eight SSR with an average of 4.88 alleles per polymor-phic loci. The average PIC was 0.42. The gene diversity among the accessions ranged from 0.26 to 0.52 with an average of 0.38, indicating moderate genetic diversity. Germplasm collected from Kenya showed a moderate genetic diversity of 0.36. Higher ge-netic diversity (He<0.5) was detected within the Ethiopian and South Africa populations. Analysis of molecular variance (AMO-VA) revealed that 94% of the allele diversity was attributed to in-dividuals within populations while only 6% was distributed among the populations. The Bayesian model-based Structure method and Principal coordinate analysis (PCoA) scatter plot clustered the accessions into three groups with germplasms collected from Kenya showing distribution among all the three groups. The wild accessions clustered mainly with those from Southern and Eastern Africa confirming earlier suggestions that lablab is of Af-rican origin. The results of this study are discussed in light of the crop improvement of this crop.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 Genotypic Variability, Heritability and Path Analysis of Yield Components of Determinate Lablab (Lablab Purpureus (L.) Sweet) Inbred Lines in Kenya(2021-10) Kamau, E.M.; Kinyua, M.G.; Waturu, C.N.; Karanja, D.R.; Kenya Agriculture and Livestock Research Organization ; University of EldoretLablab is a leguminous crop that offers great potential as food and cash crop in Kenya. However, high yielding early maturing determinate varieties suitable for short season environments and for intercropping systems are lacking. This study was conducted to estimate heritability, genetic advance and correlation between grain yields and yield attributing traits of advanced inbred determinate lines. Thirty nine lablab F5 inbred lines and a local determinate accession were evaluated at KALRO Katumani and Thika using randomized complete block design (RCBD) with two replications in 2017. Significant differences (P< 0.05) were observed among the genotypes for all the characters. Phenotypic coefficient of variability (PCV) and genotypic coefficient of variability (GCV) were highest for seed weight per plant and the lowest for maturity traits. Broad heritability for the 11 characters was moderate to high ranging from 0.40 - 0.86. The highest genetic gain (48.53%) was recorded on seed weight per plant and lowest on the maturity related traits. Pods number (r = +0.87) and raceme number (r = +0.81) had the highest positive and significant (P> 0.05) correlation with seed yield per plant. Path analysis revealed that pods per plant (0.68), racemes per plant (0.25) and pods per raceme (0.13) had the largest direct effect on seed yield. The study identified, moderate to high heritability and genetic advance estimates and significant positive correlations of pods per plant, raceme per plant, plant height, pod width, pods per raceme and number of flower nodes. The same traits also had high direct and indirect effects on seed yield and therefore suitable for phenotypic selection of improved determinate lablab genotypes. The results of the study are discussed in light of crop improvement of this leguminous crop.Item Kenya Agricultural Research Institute Manual Guide(Ministry of Agriculture, 2007) Ministry of Agriculture; Wabule, M.N.; Waturu, C.N.; Ayiemba, J.A.Asian vegetables are some of the upcoming/crops grown by small and large scale farmers and constitute high value horticultural export crops. Yields are generally low, due to large number of pests and diseases. Information about these pests and diseases have bee~ gathered by research scientist at KARI Thika and have been described in this manual, together with symptoms and damage they cause. Also presented are the recommended methods of control, with emphasis on Integrated Pest Management (IPM) where possible.
