MARION WARIGIA

Aims: This study was conducted to evaluate partial resistance to Maize Streak Virus (MSV) in F2 segregating population derived from a single cross of two inbred lines VLO73311 (resistant) and CLRCW92 (susceptible). Study Design: The experimental design was an incomplete block design replicated two times. Place and Duration of Study: Department of plant sciences Kenya Agricultural and Livestock Research Institute in Biotechnology center laboratory, in June 2014 to December 2015. Methodology: Resistance was evaluated in replicated field trials under artificial inoculation while selecting using SNP markers. The method of composite interval mapping was employed for QTL detection with a linkage map based on 350 SNP markers. Results: The final linkage map comprised of 100 individuals and 61 SNP markers distributed in ten linkage maps and covering a distance of 437.282cM. One QTL located in linkage group four was detected with a LOD score of above 2.0 with two SNP markers (PZA00413_20 and ...

Aphids are among pests of economic importance throughout the world. Together with transmitting plant viruses, aphids are capable of inflicting severe crop production losses. They also excrete honeydew that favours the growth of sooty mold which reduces the quality of vegetables and fruits and hence their market values. Rapid and accurate identification of aphids to the species level is a critical component in effective pest management and plant quarantine systems. Even though morphological taxonomy has made a tremendous impact on species-level identifications, polymorphism, morphological plasticity and immature stages are among the many challenges to accurate identification. In addition, their small size, presence of cryptic species and damaged specimens dictate the need for a strategy that will ensure timely and accurate identification. In this study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based on mitochondrial cytochrome c oxidase subunit I ...

Background: Rift Valley Fever (RVF) is a mosquito borne viral zoonosis, first reported in the Rift Valley of Kenya in 1931. In the last major outbreak of 2006/2007 in Kenya, Baringo, Garissa, and Kilifi districts were major hotspots with mortality of approximately 300 human and 40,000 livestock. Methodology: Blood fed mosquitoes sampled during the outbreak were cryopreserved. Heads and abdomens of single cryopreserved blood fed mosquitoes (n = 213) (Aedes, Culex, Anopheles and Mansonia genera) were screened for RVF virus by cell culture, and RT-PCR. Putative vertebrate hosts of the virus were determined by amplification and sequencing of blood meal cytochrome c oxidase I (COI). The resultant sequences were annotated through a bioinformatic pipeline suite comprising of 1) BioEdit for initial cleaning and development of consensus sequences 2) Basic Local Alignment Search Tool (BLAST) searches against GenBank nr database to identify putative homologues of the sequences and 3) Barcode of Life Data Systems (BOLD) for COI. Results: The results of the in silico analyses implicated 3 species in 2 genera as putative vectors of the virus. Among 12 blood meal samples positive for RVFV 6 were drawn from Garissa samples and implicated goats, human and donkey while the rest were from Baringo and implicated sheep and goats as putative hosts. Conclusion: The analyses demonstrate the potential application of bioinformatics approaches when integrated to wet lab tools as accurate and effective in identification of the vertebrate hosts of RVF, with potential application in public health initiatives in understanding vector borne pathogen epidemiology, and enabling control