Abstract: In order to determine the influence of bacco plant density on the phenomenon of “high temperature induced maturity”, this paper designed five different planting densities: 13 500 plants/hm2, 15 000 plants/hm2, 16 500 plants/hm2, 17 250 plants/hm2, and 18 000 plants/hm2; and studied the field microclimate, the incidence rate of “high temperature induced maturity”, the activity of antioxidant enzymes, the chemical component and the economic characteristics with different planting densities. The results showed that the incidence rate of “high temperature induced maturity” under the treatment of 15 000 plants/hm2 was the lowest; there was no significant correlation between field microclimate and incidence rate of “high temperature induced maturity” under this treatment, which suggested the planting density did not affect the incidence of “high temperature induced maturity” with planting density of 15 000 plants/hm2. The activities of peroxidase (POD), polyphenol oxidase (PPO), superoxide dismutase (SOD), and catalase (CAT) in tobacco leaf were more active under the treatment of 15 000 plants/hm2 than those under other treatments. Under the planting density of 15 000 plants/hm2, the chemical composition of tobacco leaf was suitable and its economic characteristics were the best. Therefore, compared with other treatments, the planting density of 15 000 plants/hm2 was conducive to improve the peroxidases activity response to stress, reduce the incidence of “high temperature induced maturity”, and improve the yield and quality of flue-cured tobacco leaves.

Key words: planting density, high temperature induced maturity, enzyme activity, field microclimate, chemical component, economic characteristic

摘要： 为了解不同植烟密度对烤烟“高温逼熟”现象的影响，设计五种不同植烟密度：13 500株/hm2、15 000株/hm2、16 500株/hm2、17 250株/hm2和18 000株/hm2，研究不同植烟密度对烟株田间微气候、“高温逼熟”发生率、抗氧化酶活性、烤后烟叶化学成分和经济性状的影响。结果表明，15 000株/hm2种植密度下“高温逼熟”发生率最低，该处理下田间微气候因子与“高温逼熟”发生率没有显著相关性， 说明该处理下的“高温逼熟”发生率与种植密度无关。烟叶中的过氧化物酶(peroxidase, POD)、多酚氧化酶(polyphenol oxidase, PPO)、超氧化物歧化酶(superoxide dismutase, SOD)、过氧化氢酶(catalase, CAT)均为15 000株/hm2处理下活性较大，说明15 000株/hm2处理诱导POD、PPO、SOD和CAT活性提高，增强烟株抗逆性。15 000株/hm2种植密度下，烟叶化学成分协调性较为适宜，经济性状较好。因此，相对于其他处理，15 000株/hm2植烟密度有利于提高与抗性有关的酶活性，降低“高温逼熟”发生率，提高烟叶的产量和质量。

关键词: 植烟密度, 高温逼熟, 酶活性, 田间微气候, 化学成分, 经济性状