Expression analysis of amylase gene and starch degradation during fruit development and ripening stages of exotic cultivars of banana

Trend in expression of amylase gene along with changes in starch and total sugar contents in different banana cultivars during fruit ripening stages were examined. five exotic cultivars of banana were selected. the ripening stages of fingers were designated by changes in color from green to yellow. rt-pcr analysis revealed that expression of amylase gene was barely detectable during first three stages (6 weeks),but gradually increased at 4th stage and became very strong during 6th to 7th stage (ripening stage). a significant decrease in starch content was observed in all the cultivars at ripening stage while sugar contents increased correspondingly. in all the cultivars,the starch contents ranged from 21.8% to 24.67% at first stage and decreased to almost zero (0.32 to 0.60%) at 11th stage. on the other hand sugar contents were increased from 1% to 1.90% (23.2 to 24.2) from 1st to 11th stage. these findings have future implications in developing functional food products having desired range of sugar and starch contents in the fruit. © pakistan academy of sciences.