TITLE:
Molecular Diversity of Fusarium oxysporum and Geotrichum candidum Isolated from Two Tomato Varieties Commonly Consumed in Some Southwestern Town in Nigeria
AUTHORS:
Ayodele Adegboyega Sobowale, Olalekan Ajibolade Ogunoye
KEYWORDS:
Fusarium oxysporum, Geotricum candidum, Genetic Distances, Evolutionary Relationship and Genes
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.13 No.5,
May
31,
2022
ABSTRACT: Fusarium oxysporum and Geotrichum candidum, which are
among important pathogens of Solanum lycopersicum L. (Tomato),
are sometimes misidentified during morphological misidentification. The study
was carried out to evaluate molecular diversity of F. oxysporum and G. candidum isolated from two
tomato varieties obtained from Akure, Ilorin and Ibadan, Nigeria. The tomato
samples were collected and brought back to the laboratory for fungal isolation.
Isolation of the pathogens were done following standard procedures. DNA
extraction from pure cultures of the pathogens was done at the Centre
Laboratory of University of Ibadan. Genetic relationships among the organisms
were also estimated by constructing a Dendrogram through UPGMA using the Mega6
Software and genetic distance was computed also using the Mega6 Software. Five
strains of F. oxysporum and seven strains of G. candidum were identified. Percentage
similarity of the pathogens with those in GenBank was 99.17% - 100.00% for F. oxysporum and 98.48% - 100.00% for G. candidum. The T-01 marker showed the
lowest major allele frequency of 0.0833, while T-10 marker has the highest
value for major allele frequency of 0.6667 and an average value of 0.3958.
Evolutionary relationship showed that the two strains of G. candidum (MN650247 and
MN650250) were similar. The three strains of F. oxysporum (MN650246
and MN650248, MN650245 and MN650253) were also similar. Genetic distances among
pairs of the fungal strains ranged from 0.12 to 6.30 in pairwise fashion, with
an average of 1.32. Evolutionary relationship or closeness among strains of a
fungal species can thus be said not to depend on location.