Influence of chitosan coating combined with spermidine on anthracnose disease and qualities of 'Nam Dok Mai' mango after harvest

Chitosan (CTS) combined with spermidine (SPD) was applied as fruit coating for 'Nam Dok Mai' mango (Mangifera indica L.) compared with CTS and SPD treatments after harvest and stored at 25 +/- 2 degrees C for 9 days. Influence of all treatments on anthracnose disease and qualities of mango fruit was investigated after inoculation fruit with Colletoirichum gloeosporioides. Inoculated fruit coated with 1% CTS combined with 0.1 ppm SPD exhibited the smallest area of lesion development (0-1 cm); while non-coating inoculated fruit presented the most severe fungal decay (4-5 cm). Furthermore, inoculated fruit coated with 1% CTS combined with 0.1 ppm SPD showed higher plant defense mechanisms than control and other treated fruits. These phenomena were represented by the production of high levels of 11202 and phenolic compounds during storage and the induction of defense enzyme activities including chitinase, beta-1,3-glucanase and peroxidase whereas fruit treated with only CMS or SPD expressed lower effect on induction of plant defense mechanisms. Therefore, synergistic effect of chitosan and spermidine combination can increase the ability to inhibit anthracnose disease development on 'Nam Dok Mai' mango fruit. Delayed mango fruit softening by 1% CTS combined with 0.1 ppm SPD was in correlation with reduced soluble pectin content during ripening stage. The results obtained suggested that 1% CTS combined with 0.1 ppm SPD had potential to improve firmness and delay deterioration processes of 'Nam Dok Mai' mango fruit after harvest.