title: Chitosan controls postharvest anthracnose in bell pepper by activating defense-related enzymes.
abstract: Anthracnose, a postharvest disease caused by the fungus Colletotrichum capsici is the most devastating disease of bell pepper that causes great economic losses especially in tropical climates. Therefore, the objective of this study was to evaluate the antifungal properties of chitosan (low molecular weight from crab shell, Mw: 50 kDa and 75-85 % deacetylated) against anthracnose by inducing defense-related enzymes. The concentrations of 0, 0.5, 1.0, 1.5 and 2.0 % chitosan were used to control the fungus in vitro and postharvest. There was a reduction in C. capsici mycelial growth and the highest chitosan concentration (2.0 %) reduced the growth by 70 % after 7 days incubation. In germination test, the concentration of 1.5 and 2.0 % chitosan reduced spore germination in C. capsici between 80 % and 84 %, respectively. In postharvest trial the concentration of 1.5 % decreased the anthracnose severity in pepper fruit by approximately 76 % after 28 days of storage (10 ± 1 °C; 80 % RH). For enzymatic activities, the concentration of 1.5 and 2.0 % chitosan increased the polyphenol oxidase (PPO), peroxidase (POD) and total phenolics in inoculated bell pepper during storage. Based on these results, the chitosan presents antifungal properties against C. capsici, as well as potential to induce resistance on bell pepper.
authors.affiliation: Centre of Excellence for Postharvest Biotechnology (CEPB), School of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Semenyih, 43500 Selangor Darul Ehsan Malaysia.
authors.forename: Madushani
authors.initials: M
authors.lastname: Edirisinghe
authors.affiliation: Centre of Excellence for Postharvest Biotechnology (CEPB), School of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Semenyih, 43500 Selangor Darul Ehsan Malaysia.
authors.forename: Asgar
authors.initials: A
authors.lastname: Ali
authors.affiliation: Centre of Excellence for Postharvest Biotechnology (CEPB), School of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Semenyih, 43500 Selangor Darul Ehsan Malaysia.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Maqbool
authors.affiliation: School of Biosciences, The University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD UK.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Alderson
keywords: Capsicum annuum; Chitosan; Colletotrichum capsici; Peroxidase; Polyphenol oxidase; Total phenolics