Abstract
Botrytis cinerea and Alternaria alternata are two necrotrophic fungal pathogens causing grey and black mould respectively on horticultural crops, including tomatoes and grapes, leading to enormous preharvest and postharvest losses worldwide. Aureobasidium pullulans is a yeast-like saprophytic fungus which naturally inhabits plant and fruit surfaces and is a potential biocontrol agent against a wide range of pathogenic fungi. Production of antifungal volatile organic compounds (VOC) has been postulated as one of the biocontrol mechanisms of A. pullulans. In this study the efficacy of antifungal VOC from four A. pullulans isolates were tested in vitro against two B. cinerea isolates from tomato and wine grapes and one A. alternata isolate from tomato using a double Petri dish assay. Two base Petri dishes containing PDA were stacked open-end to open-end. A. pullulans was inoculated on the upper dish and the pathogen inoculated on the second (lower). Inhibition of radial growth of the pathogen colony was measured. In a second experiment a Petri dish containing a glass slide with a pathogen conidial suspension in PDB was exposed to the A. pullulans inoculated dish to assess the inhibition of conidia germination. Exposure to the headspace of four A. pullulans isolates caused a 37- 85 % reduction of colony diameter of B. cinerea and 35-47 % for A. alternata compared to non-fumigated controls after three days of incubation at 25 °C. A. pullulans VOC also inhibited conidial germination of the three pathogen isolates, by 29-75% and 22-83% for the A. alternata and B. cinerea isolates respectively. Morphological deformations were observed in fumigated conidia and germ tubes of the pathogens when exposed to the headspace of the A. pullulans culture. To elucidate the nature of the A. pullulans VOC, the culture headspace was analysed by SPME-GC-MS. Thirteen VOC were identified that included alcohols, ketones and esters
| Original language | English |
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| Pages | 102 |
| Number of pages | 1 |
| Publication status | Published - 2019 |
| Event | V International Symposium on Postharvest Pathology - University of Liege, Liege, Belgium Duration: 19 May 2019 → 24 May 2019 https://events.uliege.be/postharvest2019/ (Conference website) |
Conference
| Conference | V International Symposium on Postharvest Pathology |
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| Abbreviated title | From consumer to laboratory - Sustainable approaches to managing postharvest pathogens |
| Country/Territory | Belgium |
| City | Liege |
| Period | 19/05/19 → 24/05/19 |
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