【摘要】 对不同氮肥用量条件下大田期烤烟硝酸还原酶(NRase)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性变化及烤后烟叶的主要质量指标进行了分析。结果表明,在一定施氮范围内,NRase活性在整个生育期表现为前期升高中期下降后期又略有升高,其活性大小与施氮量成正比;POD活性则持续下降,尤其在移栽后50～60d降幅最大,同期POD活性随施氮量增加而略有升高;大田生长期,CAT活性总体呈下降趋势,其活性随施氮量不同变幅明显,其中施氮量较少的处理B和不施氮肥(CK)的处理A较施氮量较多的处理D和E变化剧烈。NRase、POD和CAT的酶活性表现为正相关,且相关系数均达极显著水平。氮肥施用量与烤后烟叶的烟碱和淀粉含量均呈极显著正相关,相关系数分别为0.8284和0.7099,且对中部叶烟碱含量的影响最大,其次是下部叶和上部叶。烤后烟叶烟碱与淀粉含量呈极显著正相关,相关系数为0.8703;而烟碱与总糖、钾的含量则表现为负相关。更多还原

【Abstract】 This experiment was carried out to study certain enzyme activity and quality of cured leaves during field time under different nitrogen rates. The results showed that the activity of NRase was descended in middle period after rising first, slightly ascended finally under certain nitrogen rates ranges. And its activity had a direct ratio with nitrogen fertilizer amount. Activity of POD kept declining for all the periods. Especially during 50 to 60 days after transplanting dates, the degree of declining was the largest. However the activity POD was slightly rising with increasing of nitrogen rates. The decreasing tendency of CAT activity was visible during growth period. Moreover its activity varied significantly under different nitrogen rates. The influence was more apparent in lower nitrogen rates which included B and A treatment than the higher rates treatment D and E. The correlation analysis showed that the correlations among all enzyme activities were positive and significant. Meanwhile the contents of nicotine and starch were positive to the nitrogen using rates, the correlation coefficient were 0.828 4 and 0.709 9 respectively ,and the most apparent effect of different nitrogen rates in nicotine was produced in middle leaves,the lower and upper leaves successively. The correlation between nicotine and starch contents was positive and significant,the correlation coefficient was 0.870 3;the correlation between nicotine and potassium were negative significantly.更多还原