关键词: 雪茄, 采收时间, 碳氮代谢, 化学成分

Abstract: In order to explore the production conditions of good quality cigars, and understand the physiological and biochemical changing rules of cigars harvested at different time, and determine the appropriate harvesting time and maturity degree of cigars, this paper studied the changing rules of key enzymes activity in carbon and nitrogen metabolism, and chemical composition of cigar leaves harvested at different times by field experiments. The results showed that the activity of nitrate reductase in the middle leaves decreased gradually along with the postpone of harvesting time, while the upper leaves increased first then decreased. The activity of amylase in the middle and upper leaves decreased first then increased with the postpone of harvesting time. The contents of total nitrogen, total sugar, reducing sugar and starch in the middle and upper leaves increased first then decreased with the postpone of harvesting time. The decrease in contents of total sugar, reducing sugar and starch in the upper leaves at 45～50 d after topping was not remarkable. The chemical contents in the middle leaves at 35～40 d after topping were significantly decreased. Therefore, it was suggested that the middle leaves of cigar should be harvested at 35 d after topping, and upper leaves should be harvested at 45～50 d after topping. These research findings provided theoretical basis for harvesting cigar timely in Wuzhishan, Hainan province.

Key words: cigar, harvesting time, carbon and nitrogen metabolism, chemical composition