【摘要】 生长初期,土壤pH值与膜透性和POD活性基本呈负相关。pH值从4.5到8.5,细胞膜透性随之减小,POD活性下降;而SOD CAT活性和MDA含量则是随着pH值的升高而增加。成熟期,随土壤pH值的升高,CAT、POD活性和细胞膜透性下降,SOD活性 增加;MDA含量表现为,pH4.5～6.5处理的呈增加趋势,pH7.5～8.5处理的呈下降趋势,pH8.5处理的MDA含量最低。从整个 生育期看,随着烟叶进入成熟期,烟叶内保护酶活性表现为:SOD、CAT下降,POD增加,膜质过氧化产物MDA含量增加,细胞膜 透性加大。更多还原

【Abstract】 In early growth period, soil pH had negative correlation with the membrane permeability and the activity of POD declined when the pH value was up from 4.5 to 8.5 while the activity of SOD and CAD as well as the content of MDA increased with the rising of pH value. In mature stage, with the rising of soil pH the activity of CAT and POD as well as the membrane permeability declined while the activity of SOD increased. The content of MDA had an increasing tendency when the pH value was up from 4.5 to 6.5 and declining tendency when the pH value was up from 7.5 to 8.5 and reached its minimum value on soil pH 8.5. In view of the whole growth period, with the tobacco leaves entering the mature stage, the activity of SOD and CAT declined while the activity of POD increased. The content of MDA which is the product of membrane-lipid peroxidation and the membrane permeability increased.更多还原