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Poster: Diseases of Plants: Disease Detection & Diagnosis


Occurrence of Phytophthora syringae causing Phytophthora fruit rot in apple in Chile
G. DÍAZ (1), M. Lolas (1), R. Méndez (1), J. Contreras (2), M. Caceres (1) (1) Universidad de Talca, Chile; (2) Univerisdad de Talca, Chile

CChilean apple industry is one of the major exporter of fresh apples worldwide with an export volume of 628.247 ton. Maule Region (35°25´) is the most important apple production region in Chile with a 60% of production of fresh apple. The fungal diseases in postharvest, is one of the major problems for Chilean industry of fresh apple. Recently was described speck rot caused by Phacidiopycnis washingtonensis in apple in Chile. During survey for postharvest diseases of apple in 2014-2015, a postharvest rot was observed on stored apple cv. Jonagold and Pink Lady collected in packinghouses. Symptomatic apples (n=40) were characterized by an initial light brown skin discoloration with spongy to firm flesh texture. With the objective to isolate the causal agent, small fragments were collected from diseased tissues and aseptically placed on Corn Meal Agar and PDA. A Phytophthora sp. was consistently isolated. Eight representative Phytophthora isolates were characterized for morphological and molecular identification, pathogenicity tests and sensitivity to fungicide. Based on morphology and phylogenetic analyses, this fungus was identified as Phytophthora syringae. All isolates grew at 0°C. Inoculated apple fruits developed necrotic lesions. The isolates were sensitive to dimethomorph. To our knowledge, this study is the first description of P. syringae causing Phytophthora fruit rot on apple during postharvest in Chile