Morphological, molecular and pathogenic diagnostic of fungi in lawn’s root and neck in Mexico

Abstract

The illnesses that cause root and neck rot in golf courses constitute a limiting factor for grass development worldwide. This is mainly true when management guidelines are not conducted. Our research was conducted in the Golf Club “Mexico”, located in Mexico, D.F. Isolates were taken from plants that presented yellowing symptoms and root and neck rot. The identified pathogenic fungi, isolated from axenic media, were Giberella avenacea, Fusarium oxysporum, F. oxysporum f. sp. cubense and Pythium ultimum. The molecular characterization showed a comparison of the DNA-obtained sequences which was morphologically determined as F. avenaceum and was molecularly corroborated as G. avenacea with a similarity of 96%. Comparison between the obtained DNA sequences which were morphologically determined as F. oxysporum, were molecularly corroborated as F. oxysporum with a similarity of 97%. Finally, the DNA fungi sequence comparisons that were morphologically determined as F. oxysporum, were molecularly corroborated as F. oxysporum f. sp. cubense with a similarity of 97%. It was proved that the study fungi were the causal agents of the symptoms at the field because their inoculation in grass growing in plots (at the greenhouse) determined the same symptoms. The re-isolates were identified as the inoculated species, and in this way the Koch’s postulates were fulfilled.