1-Methylcyclopropene treatment affects strawberry fruit decay

Strawberry cv. Everest fruit were treated with 1-methylcyclopropene (I-MCP) at various concentrations from 0 to 1000 nl/l for 2 h at 20 degreesC. They were then kept individually in closed but vented containers for 3 days in the dark at 20 degreesC and 95 - 100% relative humidity. 1-MCP treatment tended to maintain strawberry fruit firmness and colour. However. disease development was accelerated in fruit treated at high (500 and 1000 nl/l) I-MCP concentrations. I-MCP treatment also lowered ethylene production. Treatment with I-MCP inhibited phenylalanine ammmonia-lyase (PAL) activity, and lowered increases in anthocyanin and phenolic contents. Comparatively low levels of phenolics in fruit treated at the highest I-MCP concentration (1000 nl/l) could account for decreased disease resistance of these fruit. (C) 2001 Elsevier Science BN. All rights reserved