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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
The effects of mycological media and temperature on mycelial growth and spore production of three fungal pathogens recently reported on Ricinodendron heudelotii were investigated. The pathogens were identified on the basis of the ITS sequences of their ribosomal DNA as Pestalotiopsis microspora (isolate PMHP_109L), Lasiodiplodia theobromae (isolate LTHP_110L) and Fusarium oxysporum (isolates FOBR_164S, FOBR_049L and FOHP_121L). The radial growth (mm/day) of the fungi and conidia concentrations (number of conidia/ml of suspension) were assessed on three culture media: potato dextrose agar (PDA), malt extract agar (MEA) and V8 juice agar (V8). All media were suitable for the growth of L. theobromae while V8 juice agar supported the fastest mycelial growth rate in P. microspora (13.4 mm/day). PDA and MEA media were appropriate for F. oxysporum. The growth rate and conidia concentration increased with temperature and attained their optimum at 23oC for P. microspora and L. theobromae and 28oC for Fusarium oxysporum strains. There was no growth of P. microspora and L. theobromae at 33oC while at this temperature, Fusarium oxysporum strains continued to grow and produce spores. The best temperature for spore production was 23oC for P. microspora, 28oC for F. oxyporum and 21, 23 and 28oC for L. theobromae. F. oxysporum isolates produced the highest concentration of conidia in all the culture media. These data contribute to the knowledge of the biology of these newly recognized parasitic fungi on R. heudelotii and show that species like F. oxysporum possesses a high level of phenotypic plasticity that allows it to survive and proliferate over a wide range of environmental conditions.