Effect of chitosan on anthracnose disease and physiology of harvested chili 'Jinda'
Chili pepper fruits 'Jinda' were wound-inoculated with the anthracnose pathogen Colletotrichum gloeosporioides, and then coated with chitosan solution at 0 (control), 1.2 or 1.6% (w/v). Chitosan delayed disease development and weight loss, with 1.6% giving better results than 1.2%. However, 1.6% chitosan caused fruit fermentation. Chitosan coating at 1.2% reduced respiration rate and ethylene production, but did not delay firmness loss or color changes (L* and a* values). The effect of 1.2% chitosan coating on the induction of peroxidase (POD), phenylalanine-ammonia lyase (PAL), β-1,3-glucanase (GLU) and chitinase (CHI) activities was determined in chili fruits after wound-inoculation with C. gloeosporioides for 0 to 48 h. The result showed that chitosan coating had not induced these enzymes, but POD, GLU and CHI increased in response to wounding. This result implies that the delayed disease development may not be caused by an indirect effect of chitosan to induce plant defense response, but by its direct effect.
Jitareerat, P., Uthairatanakij, A. and Aiamla-or, S. (2017). Effect of chitosan on anthracnose disease and physiology of harvested chili 'Jinda'. Acta Hortic. 1179, 119-124
beta-1,3-glucanase, Capsicum sp., chitinase, Colletotrichum gloeosporioides, peroxidase, phenylalanine-ammonia lyase