Delayed ripening of 'Bartlett' pears treated with nitric oxide

• Published in: The journal of horticultural science & biotechnology Vol. 78; no. 6; pp. 899 - 903
• Main Authors: Sozzi, Gabriel O., Trinchero, Gustavo D., Fraschina, Adela A.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 2003
• ISSN: 1462-0316; 2380-4084
• DOI: 10.1080/14620316.2003.11511716

Preclimacteric European pears (Pyrus communis L. 'Bartlett') were either untreated or treated with 10 μl l -1 nitric oxide (NO) at 20°C for 2 h and then kept at 20°C. Other lots were treated with 0, 10 or 50 μl l -1 NO for 12 h. In pears treated with 10 μl l -1 NO for 2 h the ethylene climacteric was delayed 4 d, maximum ethylene production decreased by 28% and firmness and colour changes had a 2 d delay. An additional treatment with 10 μl l -1 NO after 4 d decreased ethylene production even further (48%). In contrast, pears treated with 50 μl l -1 NO for 12 h displayed a 719-fold increase in ethylene biosynthesis 1 d following treatment. This sharp increase in ethylene emission, characteristic of a stress response, did not accelerate the normal progress of ripening-related events. In fruit treated with 10 and 50 μl l -1 NO for 12 h, yellowing was delayed 2 d in comparison with control fruit while the softening rate was almost unaffected. Thus, different ripening processes are not influenced in the same fashion by NO treatments. Results suggest a time × concentration effect when NO is applied.