Poster Presentation Science Protecting Plant Health 2017

“The difference between ‘Braeburn’ and ‘Golden Delicious’ apple fruit in susceptibility and antioxidant response to postharvest disease caused by the grey mould fungus, Botrytis cinerea.” (#104)

Tuyet T.A. Bui 1 2 , Sandra A.I. Wright 1 , Anders B. Falk 3 , Tanja Vanwalleghem 4 , Wendy Van Hemelrijck 4 , Maarten T. M. Hertog 5 , Bart M. Nicolai 5 , Johan W. Keulemans 2 , Mark W. Davey 2 6
  1. University of Gävle, Gävle, GäVLE, Sweden
  2. Lab. of Fruit Breeding and Biotechnology, Department of Biosystems, Faculty of Bioscience, K.U. Leuven , Leuven, Belgium
  3. Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
  4. Proefcentrum Fruitteelt vzw, Sint-Truiden, Belgium
  5. Division of MeBioS, Department of Biosystems, Faculty of Bioscience Engineering, K.U. Leuven, Leuven, Belgium
  6. Bayer Crop Science, 9052, Zwijnaarde, Zwijnaarde, Belgium

Apples are rich in vitamin C and other antioxidants, which is beneficial to human health. Apples are usually harvested in September - October, and then stored for many months in order to maintain a supply of high quality over a long period of time. During post-harvest storage, there are several losses as a result of disorders and diseases, such as the grey mould (Botrytis cinerea). The present work compares the involvement of antioxidant metabolism of two different apple cultivars ‘Braeburn’ and ‘Golden Delicious’ in their susceptibility to artificial inoculation with grey mould. Apple fruit of ‘Braeburn’ and ‘Golden Delicious’ were inoculated with artificial grey mould on both sides of the fruit and antioxidant metabolism of the two apple cultivars were measured over time in peel and flesh tissues taken both sides of the fruit. Overall, ‘Braeburn’ was more susceptibility than ‘Golden Delicious’, even though ‘Braeburn’ had higher levels of metabolism in several antioxidants than ‘Golden Delicious’, such as total vitamin C content in peel, phenolic compound in flesh and superoxide (SOD) activity and flavonoid peroxidase (POX) activity in flesh tissues. In ‘Braeburn’, it was a clear response of antioxidant metabolism to inoculation with grey mould, involving an increase SOD activity and ascorbate peroxidase (APX) activity, and a decrease POX activity, vitamin C content and phenolic compound. In ‘Braebun’, disease developed more rapidly on the shaded than on the sun-exposed side with the sun-exposed side had higher vitamin C content and metabolism enzyme activity. In ‘Golden Delicious’, vitamin C content and antioxidant enzyme were not significantly induced by inoculation with grey mould, suggested that ‘Golden Delicious’ presents a different line of defence to grey mould. Preharvest exposure to high light/high temperature stress can reduce the susceptibility of apples to postharvest pathogens, but that the response also depends on the apple cultivar.