Author(s): GELAIN, J.; ALVES, S. A. M.; MOREIRA, R. R.; MIO, L. L. M. de

Summary: European Canker and Neonectria fruit rot (NFR), caused by Neonectria ditissima, has become a major problem for the production of apples (Malus domestica) in Brazil. This study characterized environmental factors affecting in vitro growth and germination of Neonectria ditissima as well as infection, colonization and reproduction, ex vivo, on ?Gala? and ?Eva? fruit. Temperatures between 17 to 20 °C were optimum for mycelial growth, and minimal growth occurred at 35 °C. Micro/macroconidia sporulation ratio was lower at 10 °C for most of the isolates tested, and no macroconidia were produced at 30 °C. More than 70% of conidia germinated after 12 h of exposure to constant humidity incubation and a temperature of 25 °C. Germination rate as high as 90% occurred after 48 h regardless of the temperature. Incubation of 2 h with high humidity is not sufficient for germination of 10% of conidia at any temperature between 10 to 30 °C. The cultivars Eva and Gala did not differ in relation to incubation period. A minimum of 25 days was necessary for sporulation on fruit incubated at 16.8?21.7 °C. Unwounded fruit did not present symptoms even 40 days after inoculation on intact epidermis, demonstrating the need of wounds for NFR development. Keywords Cylindrocarpon heteronema . Malus domestica . Nectria galligena . Basic biology . Postharvest disease

Publication year: 2020

Types of publication: Journal article

Unit: Embrapa Grape & Wine

Keywords: Basic biology, Cylindrocarpon heteronema, Malus Domestica, Nectria galligena, Postharvest disease