Skip to main content
ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #155406
Title: THE EFFECTS OF LOW DOSE ULTRAVIOLET LIGHT-C TREATMENT ON POLYGALACTURONASE ACTIVITY ON DELAYED RIPENING AND RHIZOPUS SOFT ROT DEVELOPMENT OF TOMATOES

Author
item STEVENS, C. - TUSKEGEE UNIVERSITY
item LIU, J. - TUSKEGEE UNIVERSITY
item KHAN, V. - TUSKEGEE UNIVERSITY
item LU, J. - TUSKEGEE UNIVERSITY
item KABWE, M - TUSKEGEE UNIVERSITY
item Wilson, Charles
item IGWEGBE, E - TUSKEGEE UNIVERSITY
item CHALUTZ, E - ARO, THE VOLCANI CTR
item DROBY, S - ARO, THE VOLCANI CTR

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2004
Publication Date: 10/5/2004
Citation: Stevens, C., Liu, J., Khan, V.A., Lu, J.Y., Kabwe, M.K., Wilson, C.L., Igwegbe, E., Chalutz, E., Droby, S. 2004. The effects of low dose ultraviolet light-c treatment on polygalacturonase activity on delayed ripening and rhizopus soft rot development of tomatoes. Crop Protection Journal 23 (2004)p. 551-554.

Interpretive Summary: Rhizopus soft rot caused by the fungus Rhizopus stolonifer is one of the most destructive postharvest storage diseases of tomato. A critical need exists for new means of controlling Rhizopus rot that is safe for the consumer and friendly to the environment. Scientists at Tuskegee University, USDA ARS Appalachian Fruit Research Station, ARO, Volcani Center, Israel have discovered that low-dose UV-C light has the capability of "turning on" resistance in harvested commodities and making them more resistant to postharvest decay. When this technology was applied to tomato it was discovered that it made the tomato fruit firmer and more resistant to infection to infection by the rot fungus Rhizopus stolonifer. This research has uncovered a safe and effective means of controlling postharvest decay of tomatoes and reduces the need for the application of synthetic pesticides.

Technical Abstract: Low dose application of hormetic doses of ultraviolet light-C (UV-C) to 'Better Boy' and 'Floradade' tomatoes resulted in fruits that were significantly firmer than non-irradiated control fruits at the same state of maturity. As softness decreased following UV-C treatment, polygalacturonase (PG) activity decreased. The enzyme activity was lower for UV-C treated fruits than the control. The PG activity in crude extract from decayed tomato tissue infected with Rhizopus stolonifer was lower than non-decayed fruits. UV-C treated tomatoes showed a 40% reduction in PG activity in decayed tissue compared to the control at 72 h after UV-C treatment. The lesion diameter, and percent infection of non-treated and UV-C treated tomatoes at 72 h after treatment was 13.4 mm (100% infection) and 5.3 mm (47% infection), respectively.