Induction of red skin and improvement of fruit quality in ‘Kent’, 'Shelly' and ‘Maya’ mangoes by preharvest spraying of prohydrojasmon at the orchard

Abstract

Red-blushed skin color is important for mango fruit quality and marketability. Preharvest spraying of ‘Kent’, 'Shelly' and’ Maya’ mangoes with 0.1, 0.2 or 0.4 % prohydrojasmon (PDJ) induced red skin color (areal coverage and intensity) and anthocyanins accumulation especially in fruit from the outer side of tree canopy, which were exposed to sunlight. Maximum red blush was achieved with 0.2% (‘Shelly’) and 0.4 % (‘Kent’ and ‘Maya’) PDJ in fruit from outside the canopy, with an increase of three fold in anthocyanins and two fold increase in flavonols. HPLC analysis of non-hydrolyzed samples showed that the major anthocyanin peaks were cyanidin-3-galactoside and 7-O-methylcyanidin-3-O-β-D-galactopyranoside, and the major flavonol peaks were glucoside derivatives of quercetin and kaempferol. Thus, PDJ activated the phenylpropanoid and anthocyanin pathways mainly with exposure to sunlight, allowing potential production of specific antioxidant and antifungal flavonols and anthocyanins. Induced red skin color in most of the experiments reduced postharvest decay, which may enhance commercial value and extend shelf life.