2018 ASHS Annual Conference

Nanotechnology has the potential to revolutionize the food industry by enhancing productivity, resource efficiency, nutritional quality, and consumer-preferred functional (health-promoting) properties in a cost-effective manner. In this study, we investigated the impact of nano-based seed priming on productivity and accumulation of health-promoting compounds (ascorbic acid, lycopene, and L-citrulline) in watermelon. Silver nanoparticles (AgNPs) were synthesized using onion bulb extracts which have been shown to activate seed phytohormones as well as to stimulate physiological processes and growth. The AgNP-delivery system was used to prime seeds of two watermelon varieties namely: Riverside (diploid) and Maxima (triploid). AgNP priming was compared with a turmeric oil nanoemulsion while dry unprimed seeds were used as controls. Following seed priming, seedlings were raised in a greenhouse and later field-transplanted at four locations within Texas; Edinburg, Pecos, Grapeland and Snook. An increase in lycopene, total ascorbic acid and L-citrulline contents was observed in fruits of Riverside nano-primed with AgNPs. Total ascorbic acid was increased by 54.6 % (Snook), 25% (Grapeland), 10% (Edinburg) and 7% (Pecos) in compared to controls. L-citrulline levels increased up to 62% in fruits of AgNPs treated plants grown in Pecos. Similarly, lycopene contents in fruits of AgNPs treated Riverside seeds were relatively higher in all the locations compared to the control. No consistent changes in nutritional levels were observed in fruits of Maxima. Similarly, seed treatment with turmeric oil nanoemulsion did not have any significant effects on fruit quality of both varieties. These observations suggest that seed priming with AgNPs as a delivery system has a potential to enhance post-harvest fruit functional quality and that outcomes could depend on cultivar, ploidy level, as well as production location. Further investigations are needed to characterize these interactions.