RIPENING OF CLIMACTERIC FRUITS AND THEIR CONTROL

Ripening is the final stage of development of a fruit, which involves series of physiological and biochemical events that make them both attractive and tasty to eat. Phytohormones play an important role in fruit ripening. Treatment with ethylene is required for normal fruit ripening of climacteric fruits. The fruit ripening can be controlled or delayed by physical methods such as modified atmosphere by packaging, treatment with gamma irridiation, surface coating with sucrose ester, etc. The treatments with phytohormones, reducing agents and 1-methylenecyclopropene have also been successful in delaying fruit ripening. Molecular biology tools such as transgenic plants with suppression of genes involved in ethylene synthesis or overexpression of genes for ethylene degradation, virus-induced gene silencing and manipulation of transcription factors have been successfully utilized for controlling or regulating fruits ripening. PRACTICAL APPLICATIONS Fruits play a vital role in human nutrition. One of the limited factors that influence their economic value is the relatively short ripening period and reduced postharvest life. Overripening of fruits leads to excessive softening which results in spoilage and damage during shipping and handling. Slowing the process of ripening and senescence extends the storage and shelf life of fresh fruits. Increment in shelf life of fruits not only helps the grower to save on postharvest losses but consumers are also benefited in terms of retained freshness of fruit for longer period and thus results in value addition to the fruit.