New Zealand Plant Protection 65 (2012): 297
The host-specific fungal pathogen Ciborinia camelliae is a significant pest of ornamental Camellia plants. It is the causal agent of "Camellia flower blight", which has become rampant throughout New Zealand since the pathogen's accidental introduction in the early 1990s. This study aims to profile the infection of C. camelliae in petals of resistant Camellia lutchuensis and susceptible Camellia japonica × Camellia pitardii "Nicky Crisp" plants. Petals were harvested from glasshouse-grown plants and infected with field-collected fungal ascospores. Microscopic analysis of the incompatible interaction at 24 hours post inoculation (hpi) revealed many hallmarks of non-host resistance, including papilla formation and H2O2 accumulation. Localised cell death was also observed in epidermal cells in direct vicinity of ascospores. In comparison, the compatible interaction produced lesions by 30 hpi that completely enveloped the petal tissue by 72 hpi. RNA was isolated from incompatible and compatible interactions at 48 hpi. Deep sequencing of the mRNA resulted in a total of 340 million high quality cDNA reads. Preliminary analysis of the compatible transcriptome identified the expression of 23 putative fungal virulence factors that have previously been characterised in other members of the Sclerotiniaceae.
Copyright © 2012 New Zealand Plant Protection Society (Inc.).