บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Pre- and postharvest induction of temperature tolerance in fruit: whole fruit, cells and genes

I B Ferguson

Proceedings of the APEC symposium on postharvest handling systems Bangkok, Thailand September 1-3, 2003. p. 115

2003

บทคัดย่อ

Pre- and postharvest induction of temperature tolerance in fruit: whole fruit, cells and genes One of the biggest problems with fruit storage, particularly postharvest storage of tropical and sub-tropical fruit, is damage due to low and high temperatures. It is therefore a prime objective of postharvest study to find ways of inducing temperature tolerance, and of understanding what contributes to tolerance, both o­n the tree and in postharvest storage and handling.

Both pre- and postharvest temperature history of fruit, have a strong influence o­n the way in which a fruit responds to postharvest storage and handling conditions. Studies o­n disinfestation methods have shown that many fruit will withstand temperatures above 50 °C necessary to kill insects if exposed to high, but non-damaging temperatures first (acquired thermotolerance). We have shown that fruit exposed to direct sunlight o­n the tree can reach temperatures greater than 45 °C. Experience of these temperatures may provide protection against subsequent low temperature damage in postharvest storage. Fruit susceptible to low temperature damage can also be protected by exposure to low non-damaging temperatures prior to transfer to damaging temperatures such as 0 °C (conditioning).

These results suggest that there is a commonality in such responses of fruit. There are obviously protective mechanisms which are turned o­n when fruit undergo shifts in temperature. Some may be common to high and low temperatures, perhaps related to temperature shift rather than critical temperatures themselves. Others will be specific to high or low temperatures. Our research has shown that it is likely that the basis of this tolerance lies with specific proteins which afford protection in the cell, and with acquired tolerance to potential oxidative damage. We have been able to model these responses in cultured fruit cells, and are exploring gene changes associated with possible protective mechanisms.

Acquired tolerance, either to high or low temperatures, and both pre and postharvest, may provide strategies for prolonging storage life of commodities, and for reducing temperature induced damage in fruit which store poorly.