SUGAR ACCUMULATION IN 'SMOOTH CAYENNE' PINEAPPLE FRUITS IN DIFFERENT HARVEST SEASONS

Fruits of ‘Smooth Cayenne’ pineapple that were harvested in July (summer) matured more quickly and had greater mass than fruits that matured in February (winter). The pattern of sugar accumulation was also different. Fruit harvested in February had a hexose:sucrose ratio of 0.37 and sucrose was mainly accumulated. Fruit harvested in July had a hexose:sucrose ratio of 5.92 and more hexose was accumulated. There was significant difference in sugar accumulation and sucrose metabolism enzymes between fruits harvested in February and July. The activities of sucrose phosphate synthase and sucrose synthase synthetic direction in fruits harvested in February were significantly higher than those in July, whereas the invertase activities in fruits maturated in February was significantly lower than those in July. This profile of sucrose metabolism enzymes was favorable to sucrose accumulation for fruits harvested in February. The result of ascending invertases was that fruits that maturated in July accumulated less sucrose and more hexose than was the case for fruits that mature in February.