1-Methylcyclopropene Delays Softening in Tomato Slices

I-Methylcyclopropene (1-MCP) has the potential in tomato to reduce ethylene-associated changes in texture. Tomato cv. 'Revolution' was harvested at the 'pink' maturity stage and whole fruit treated with 0, 0.1, 1.0 or 10.0 µL.L-' 1-MCP at 20 "C for 12 h. Slices of 7-mm thickness were cut using a commercial slicer, and the slices stored in vertical stacks in plastic containers at 5°C for 7 days. The application of 1-MCP reduced both ethylene production and respiration rate of slices and resulted in firmer pericarp firmness. Ethylene production was 24%, 40%, and 62% lower following 0.1, 1.0, 10.0 µL L-' 1-MCP, respectively, compared with controls. In addition, respiration rate was reduced 6%, 10% and 20% by those 1-MCP treatments. 1-MCP treatments produced 20%, 34%, and 24% higher pericarp firmness, respectively, than in fruit not treated with 1-MCP.

Impact of 1-methylcyclopropene treatment on the sensory quality of 'Bartlett' pear fruit

The ethylene biosynthesis inhibitor, 1-methylcyclopropene (1-MCP), has been commercially used to extend the storage life of European pear fruit and to allow shipment to distant markets. However, the influence of 1-MCP on the ability of fruit to ripen to an acceptable sensory quality has not been investigated in 'Bartlett' pear, one of the most aromatic of pear fruit. In the current study, early-, mid- and late-season 'Bartlett' pear fruit were treated with 0.6μLL-1 1-MCP at 0°C for 24h, 100μLL-1 ethylene at 20°C for 24h, or untreated before immediate transfer to 20°C for ripening until eating soft (13N firmness). Fruit from each treatment were subjected to objective and sensory quality evaluation once ripe. Sensory quality showed differences related to harvest maturity; the importance of harvest maturity depended on the treatment. Treatment with 1-MCP effectively slowed fruit ripening and therefore extended postharvest life, but also resulted in fully ripened pears with more desirable sensory traits, as compared with ethylene-treated and untreated pears. The enhanced sensory quality was related to higher sweetness, juiciness and pear aroma and reduced fermented aroma, gritty texture and tart taste. In addition, the sensory profiles of 1-MCP-treated pears were more stable among fruit from the three harvest dates than the ethylene-treated pears, which exhibited very different sensory profiles between early- and late-season fruits. © 2015 Elsevier B.V.

Ethylene and 1-methylcyclopropene differentially regulate gene expression during onion sprout suppression

Onion (Allium cepa) is regarded as a nonclimacteric vegetable. In onions, however, ethylene can suppress sprouting while the ethylene-binding inhibitor 1-methylcyclopropene (1-MCP) can also suppress sprout growth; yet, it is unknown how ethylene and 1-MCP elicit the same response. In this study, onions were treated with 10 mu L L(-1) ethylene or 1 mu L L(-1) 1-MCP individually or in combination for 24 h at 20 degrees C before or after curing (6 weeks) at 20 degrees C or 28 degrees C and then stored at 1 degrees C. Following curing, a subset of these same onions was stored separately under continuous air or ethylene (10 mu L L(-1)) at 1 degrees C. Onions treated with ethylene and 1-MCP in combination after curing for 24 h had reduced sprout growth as compared with the control 25 weeks after harvest. Sprout growth following storage beyond 25 weeks was only reduced through continuous ethylene treatment. This observation was supported by a higher proportion of down-regulated genes characterized as being involved in photosynthesis, measured using a newly developed onion microarray. Physiological and biochemical data suggested that ethylene was being perceived in the presence of 1-MCP, since sprout growth was reduced in onions treated with 1-MCP and ethylene applied in combination but not when applied individually. A cluster of probes representing transcripts up-regulated by 1-MCP alone but down-regulated by ethylene alone or in the presence of 1-MCP support this suggestion. Ethylene and 1-MCP both down-regulated a probe tentatively annotated as an ethylene receptor as well as ethylene-insensitive 3, suggesting that both treatments down-regulate the perception and signaling events of ethylene.

Gibberellic acid, ozone and 1-methylcyclopropene on the gray mold control in avant garde rose

Gray mold caused by Botrytis cinerea is considered the major disease of greenhouse grown flowers. The goal of this study was to evaluate the effects of gibberellic acid (GA3), ozone, and 1-MCP, applied on postharvest, on the gray mold control in 'Avant Garde' rose. Rose flowers were artificially inoculated with B. cinerea (104 conidia ml-1) and non-inoculated. After treatments, roses were stored under room conditions (20±2°C/80±5% RH) and checked for gray mold incidence and severity. Spraying of GA3 at 25, 50, and 75 mg L-1 on non-inoculated roses reduced the area under the disease progress curve (AUDPC) of gray mold incidence in 41, 40 and 54%, respectively. Continuous application of ozone at 2.7 ppm reduced 14-folds B. cinerea sporulation. On the other hand, 1-MCP did not control gray mould in rose. These results showed that GA3 sprays and ozone contribute to postharvest control of gray mold in cut rose and can be utilized on integrated disease management.

Lisianthus vase life after 1-methylcyclopropene and salicylic acid postharvest treatment

This study evaluated the effects of application of 0.5 µl L-1 1-methyl-cyclopropene (1-MCP), 1000 mg L-1 salicylic acid (SA) and the interaction between the two products at room temperature and pre-exposure at 9±2°C for 24 h in maintaining postharvest quality of lisianthus flowers. After applying the treatment, the flowers were kept in jars with water, stored at 24±2°C. The SA treatments proved ineffective, presenting symptoms of phytotoxicity, with high rate of bent neck and yellowing of petals, both at room temperature and in cold storage, and propitiate the emergence of pathogens. The association between 1-MCP in pre-exposure to 9±2°C for 24 h increased the durability of the stems in six days compared to the control treatment, with less symptoms of bent neck and swelling of stems.