种植密度对雪茄烟膜脂过氧化特性及烟叶质量的影响

为探究不同种植密度对雪茄烟叶生理生化特性和品质的影响,确定四川雪茄烟适宜的种植密度,以德雪一号为供试材料,测定了成熟期田间微气候、烟叶膜脂过氧化程度、抗氧化酶活性和烟叶产质量等指标。结果表明,随着种植密度的增大,烟田温湿度增大,烟叶所受光照强度降低。成熟期温度与烟叶膜脂过氧化程度呈显著正相关关系,相关系数在0.52~0.85之间。同一时期内烟叶丙二醛（MDA）含量随种植密度增大呈先降后升趋势,抗氧化酶活性呈先升后降趋势。种植密度为21 000株/hm²时抗氧化酶活性最高,过氧化物酶和过氧化氢酶活性在打顶后28d达到最高,分别为61.6U/(gFW·min)和123.0U/(mg·min),超氧化物歧化酶活性在打顶后21d达到最高,为755.8U/g,打顶后35d MDA含量为25.3mmol/g,膜脂过氧化程度最低。调制后烟叶总糖含量增至1.86%,烟碱含量为3.02%,钾氯比高达9.21,化学成分较为协调,感官评吸得分最高,烟叶产值与茄衣烟比例较常规种植密度24 000株/hm²分别提升了0.9万元/hm²和7%。综上所述,21 000株/hm²为四川省雪茄烟适宜的种植密度。

Effects of Planting Density on Membrane Lipid Peroxidation Characteristics and Quality of Cigar Tobacco Leaves

In order to explore the effects of different planting densities on the physiological and biochemical characteristics and quality of cigar tobacco leaves, determine the appropriate planting density for cigar tobacco planting in Sichuan, Dexue No. 1 was used as the test material to determine the field microclimate, the degree of peroxidation of membrane lipid of tobacco leaves, the activities of related antioxidant enzymes, and the yield and quality of tobacco leaves during the mature period. The results showed that with the increase of planting density, the temperature and humidity of tobacco fields increased, and the light intensity of tobacco leaves decreased. There was a significant positive correlation between the temperature and the degree of membrane lipid peroxidation of tobacco leaves at the maturity stage, and the correlation coefficient was 0.52-0.85. During the same period, the malondialdehyde (MDA) content of tobacco leaves first decreased and then increased with the increase of planting density, and the antioxidant enzyme activity first increased and then decreased. Among them, the antioxidant enzyme activity was the highest when the planting density was 21 000 plants/ha, and the POD and CAT activities reached the highest on day 28 after topping, which were 61.6U/(gFW·min) and 123.0U/(mg·min), respectively. SOD activity was the highest (755.8U/g) on day 21 after topping, the MDA content was 25.3mmol/g on day 35 after topping, and the degree of membrane lipid peroxidation was the lowest. After modulation, the total sugar content of the tobacco leaves increased to 1.86%, the nicotine content was 3.02%, the potassium-chloride ratio was as high as 9.21, the chemical composition was more coordinated, and the sensory evaluation score was the highest. The ratio of tobacco leaf output and wrapper tobacco was increased by 9000yuan/ha and 7% respectively, compared with the conventional planting density of 24 000 plants/ha. In summary, compared with the conventional planting density of 24 000 plants/ha, 21 000 plants/ha was a suitable planting density of Sichuan cigar tobacco.