Journal of Plant Pathology (2005) 87, 296-297

B.T. Linaldeddu, C. Sirca, D. Spano and A. Franceschini (2005)
Physiological responses of cork oak and holm oak to the infections of pathogens involved in oak decline
Journal of Plant Pathology 87 (4), 296-297
XII Meeting, Italian Society for Plant Pathology, Reggio Calabria, 29/9 - 1/10, 2005 (poster)
Abstract: The endophytic fungi Biscogniauxia mediterranea, Diplodia corticola, Discula quercina and Pleurophoma cava are involved in the aetiology of oak decline in the Mediterranean area. Several studies have proved their pathogenicity, but little information is available on the physiological response of the host to their infection. The aim of this study was to investigate the changes in net photosynthesis and stomatal conductance values in 3-year-old cork oak and holm oak seedlings growing in natural conditions and inoculated with these pathogens. Throughout the three-month experimental period, the evolution of symptoms and the physiological variables were recorded every 10 days. In particular, gas exchange measurements were taken on four mature leaves from each plant exposed to sun, using an ADC 2250 infrared gas analyzer. All pathogens induced necrotic lesions around the site of infection; however, the lesions caused by D. corticola were significantly wider in both oak species. Significant and gradual reductions in net photosynthesis and stomatal conductance values were recorded on all cork oak seedlings inoculated. In the plants infected by P. cava, these physiological changes appeared just 20 days after inoculation. On holm oak physiological variables were significantly modified only by D. corticola and D. quercina infections. Seedlings inoculated with D. corticola, showed a significant decrease in photosynthetic rate (-87%) and stomatal conductance (-80%) after two months. These results, confirm on the one hand the aggressiveness of the pathogens tested and, on the other, show the different physiological responses of the two host species to infection.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Benedetto Linaldeddu, Antonio Franceschini

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Apiognomonia errabunda	Oak (Quercus)	Italy
	Biscogniauxia mediterranea	Oak (Quercus)	Italy
	Diplodia corticola	Oak (Quercus)	Italy
	Neocucurbitaria cava	Oak (Quercus)	Italy