Background and Objective:Botrytis is a serious fungal pathogen which infects most ornamental plants and its resistance to effective fungicide is a continuous challenge facing disease management. The current research aimed to identify resistant Botrytis spp. from different ornamental plants against fenhexamid. Materials and Methods: About 64 single-spore isolates were collected from different symptomatic and asymptomatic ornamental plants using the modified Kerssies medium, m1KERS. Phenotypic variability was shown in some features including growth texture, sclerotia pattern and conidial dimensions. Pathogenicity and mycelial growth rate tests were statistically carried out using one way analysis of variance (ANOVA). Molecular characterisation was demonstrated by transposable elements (TEs) analysis and fenhexamid resistance was revealed using mycelial growth assay. Results: All isolates were identified as Botrytis spp. according to their morphological and molecular characteristics. Based on phylogenetic analysis, BCLi1 isolate seemed to be distantly related to B. cinerea and other Botrytis species. Significant variation in aggressiveness among isolates was observed on detached lettuce leaves. Four TE genotypes, transposa, boty, flipper and vacuma, were detected in Botrytis populations with TE distribution reached 50, 29.7, 10.9 and 9.4%, respectively. The low virulence level of some Botrytis spp. isolates seemed to be related to vacuma isolates suggesting a possible correlation between virulence and TE genotype. Moreover, a low to moderate resistance of Botrytis spp. isolates was revealed towards the hydroxyanilide fungicide, fenhexamid, in three transposa isolates, BCT6, BCGL2 and BCGL5, with a mean EC50 value of 0.2, 0.3 and 0.5 μg mL1, respectively. Conclusion: The results demonstrated the first observation of the emergence of resistant isolates of Botrytis from ornamental plants against the highly effective fungicide in Egypt, providing a serious attention towards Botrytis management. PDFFulltextXMLReferencesCitation
How to cite this article
Hala Abdel Wahab, Elsayed E. Wagih, Mohamed R.A. Shehata, Magda M. Fahmy and Mahmoud A. Gaber, 2020. Studies on Botrytis spp. Infected Ornamental Plants and Emergence of Resistant Isolates Against Fenhexamid in Egypt. Asian Journal of Plant Pathology, 14: 1-10.