二氧化碳濃度和氮肥對樟樹苗木硝酸還原酵素活性之影響

Effect of Carbon Dioxide and Nitrogen Fertilizers on the Activity of Nitrate Reductase in Cinnamomum camphor Seedling

本研究係探討樟樹苗木在不同二氧化碳激度與氮肥處理下對硝酸還原酵素活性之影響。樟樹苗木生長於半開放式坡璃生長箱中，分別施以350 ± 20 μLL-1和700 ± 30 μLL-1 二氧化碳濃度以及氮肥（112、224、448與896 ppm）等計8種處理，栽植期間計12週。葉部及根部之硝酸還原酵素的活性皆隨著氮肥濃度的增加而增加。同一氮肥濃度處理者，提高二氧化碳濃度會使葉都之硝酸還原酵素活性減低，而根部的活性增加。由硝酸態氮濃度與硝酸還原酵素活性互為消長的關係，可得知硝酸態氯在樟樹苗木之濃度多寡受到硝酸還原酵素活性之影響。 The objective of this study was to investigate the effect of elevated carbon dioxide concentration and different nitrogen fertilizer treatments on the activities of nitrate reductase in seedlings of Cinnamomum camphora. Seedlings grown in semi open-top chambers, were treated with two different carbon dioxide concentrations (350 ± 20 p LL-1 and 700 ± 30 p LL-1) and four concentrations of nitrogen fertilizers (112, 224, 448 and 896 ppm) for 12 weeks. The activity of nitrate reductase in leaf or root of seedlings was increased by increasing nitrogen fertilizer. Compared with in 350µ LL-1 carbon dioxide, nitrate reductase activity in leave was declined in 700 µ LL-1 carbon dioxide under the same nitrogen treatment. Nitrate reductase activity of roots was higher in elevated carbon dioxide than in lower condition. The relationship between N03--N concentration and nitrate reductase activity showed that NO3-N concentration in seedlings of Cinnamomum camphora were influenced by nitrate reductase activity.

The objective of this study was to investigate the effect of elevated carbon dioxide concentration and different nitrogen fertilizer treatments on the activities of nitrate reductase in seedlings of Cinnamomum camphora. Seedlings grown in semi open-top chambers, were treated with two different carbon dioxide concentrations (350 ± 20 p LL-1 and 700 ± 30 p LL-1) and four concentrations of nitrogen fertilizers (112, 224, 448 and 896 ppm) for 12 weeks. The activity of nitrate reductase in leaf or root of seedlings was increased by increasing nitrogen fertilizer. Compared with in 350µ LL-1 carbon dioxide, nitrate reductase activity in leave was declined in 700 µ LL-1 carbon dioxide under the same nitrogen treatment. Nitrate reductase activity of roots was higher in elevated carbon dioxide than in lower condition. The relationship between N03--N concentration and nitrate reductase activity showed that NO3-N concentration in seedlings of Cinnamomum camphora were influenced by nitrate reductase activity.