ALTERNATIVE RESPIRATION AND HEAT-PRODUCTION IN RIPENING BANANA FRUITS (MUSA-PARADISIACA VAR MYSORE-KADALI)

The involvement of alternative respiration in thermogenesis during the ripening of banana (Musa paradisiaca var. Mysore Kadali) fruits, attached to a bunch, has been examined. The temperature of the youngest (unripened) banana fruit increased from 27.0+/-0.2-degrees-C to 30.8+/-0.1-degrees-C and the total respiration (in nmol oxygen min-1 g-1 dry wt.) increased from 139-6+/-5.5 to 167.3+/-7.0 at the fully ripened stage. Although the capacity for alternative respiration showed little change. the actual operation of this pathway increased from 38 to 73% (rho = 0.38 to 0.73) during ripening. Similar results were obtained in fruits along the central axis at different stages of ripening. It is suggested that alternative respiration may contribute to the temperature rise observed in ripening banana fruit.