Browsing by Author "Opiyo, S.O."

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    Genetic Diversity among Tropical Provitamin A Maize Inbred Lines and Implications for a Biofortification Program
    (Cereal research communications, 2019) Sserumaga, J.P.; Makumbi, D.; Warburton, M.L.; Opiyo, S.O.; Asea, G.; Muwonge, A.; Kasozi, C.L.
    Insights into the diversity and relationships among elite breeding materials are an important component in maize improvement programs. We genotyped 63 inbred lines bred for high levels of provitamin A using 137 single nucleotide polymorphism markers. A total of 272 alleles were detected with gene diversity of 0.36. Average genetic distance was 0.36 with 56% of the pairs of lines having between 0.30 and 0.40. Eighty-six percent of the pairs of lines showed relative kinship values <0.50, which indicated that the majority of these provitamin A inbred lines were unique. Relationship pattern and population structure analysis revealed presence of seven major groups with good agreement with Neighbour Joining clustering and somewhat correlated with pedigree and breeding origin. Utilization of this set of provitamin A lines in a new biofortification program will be aided by information from both molecular-based grouping and pedigree analysis. The results should guide breeders in selecting parents for hybrid formation and testing as a short-term objective, and parents with diverse alleles for new breeding starts as a long-term objective in a provitamin A breeding program.
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    Using Translation Elongation Factor Gene to Specifically Detect and Diagnose Fusarium xylaroides, a Causative Agent of Coffee Wilt Disease in Ethiopia, East and Central Africa
    (J Plant Pathol Microbiol, 2018) Olal, S.; Olango, N.; Kiggundu, A.; Ochwo, S.; Adriko, J.; Nanteza, A.; Matovu, E.; Lubega, G.W.; Kagezi, G.; Hakiza, G.J.; Wagoire, W.W.; Opiyo, S.O.
    The present study presents the first report on the application of DNA-based polymerase chain reaction (PCR) for the specific detection and diagnosis of F usarium xylarioides (anamorph: G ibberrela xylarioides). Fusarium xylarioides is the causative agent of Coffee wilt disease (Tracheomycosis), and the disease is the most important economic constraint in Robusta coffee production in Uganda. The pathogen has two races, one pathogenic to Robusta coffee and the other to Arabica coffee, and not vice versa. Its laboratory diagnosis has been mainly based on microscopy, which is slow, has poor discriminative power, requires high expertise, only applicable on host plants with symptoms, and has since failed to detect the pathogen from the soil. Translation Elongation factor-1α (TEF-1α) gene from a F. xylarioides isolated from infected Robusta coffee plant was amplified by Fusarium genus specific primer then the PCR product sequenced. The sequence data was then used to design the specific primer. The primer-BLAST product was found to match only F. xylarioides sequences comprising 75% of the race pathogenic to Robusta and 25% to Arabica coffee. In vitro test by PCR showed the primer to be specific to only F. xylarioides amplifying a 284bp product and was able to differentiate F. xylarioides from all closely related species of Fusarium and other plant pathogens tested. More so it was able to amplify DNA from all the F. xylarioides isolates from different regions of Uganda, and amplified DNA concentrations as minute as 0.78 ng/µL.