不同烤烟品种成熟期碳氮代谢关键酶活性的变化

为了明确南雄烟区主栽烤烟品种碳氮代谢规律,以烤烟品种粤烟97、粤烟98和K326为材料,研究了不同烤烟品种成熟期碳氮代谢关键酶活性的变化。结果表明:随着烟叶的成熟,各烤烟品种烟叶总叶绿素含量、硝酸还原酶活性、转化酶活性均表现为下降的趋势,淀粉酶活性呈先升高后下降的趋势;成熟前期粤烟98总叶绿素含量较高,粤烟97总叶绿素含量较低,但粤烟98叶绿素降解速率较快,粤烟97叶绿素降解速率较慢;成熟前期K326和粤烟98的硝酸还原酶活性极显著高于粤烟97,整个成熟期各烤烟品种间转化酶活性和淀粉酶活性差异不显著。总的来看,粤烟98碳氮代谢协调性相对较好。

Changes in Activity of Key Enzymes in Carbon-Nitrogen Metabolism of Different Flue-cured Tobacco Varieties at Mature Stage

In order to understand the rule of carbon-nitrogen metabolism of main flue-cured tobacco varieties in Nanxiong ar-ea,the author studied the changes in the activity of key enzymes in carbon-nitrogen metabolism of three flue-cured tobacco varie-ties（Yueyan 97,Yueyan 98 and K326）at mature stage. Along with the maturity of tobacco leaves,the total chlorophyll content, nitrate reductase activity,and invertase activity in the tobacco leaves of three varieties all showed a downward trend,while the amyl-ase activity increased first and then decreased. The total chlorophyll content was the highest in Yueyan 98 and the lowest in Yueyan 97 in earlier mature period,but the degradation rate of chlorophyll was higher in Yueyan 98 and lower in Yueyan 97. At earlier ma-ture stage,the nitrate reductase activity of K326 and Yueyan 98 was very significantly higher than that of Yueyan 97. There were no significant differences in invertase activity and amylase activity among various flue-cured tobacco varieties in whole mature period. On the whole,the coordination of carbon-nitrogen metabolism of Yueyan 98 was relatively good.