- 期刊
氮肥型態對苦檻藍(Myoporum bontioides)扦插苗生長、葉綠素濃度及細胞活性之影響
Effects of Nitrogen Form on the Growth, Chlorophyll Concentration and Cell Viability of Myoporum Bontioides Cuttings
摘要
本研究探討銨態氮(NH4(上標 +)-N)及硝酸態氮（NO3(上標 -)-N)不同比例（0/0、0/100、25/75、50/50、75/25及100/0）施肥處理，對苦檻藍(Myoporum bontioides)扡插苗生長、葉綠素濃度、細胞三苯基氯化四唑(Triphenyl tetrazolium chloride, TTC)還原性及生長介質pH之影響。結果顯示：處理60及90天後，扡插苗新萌芽數、萌芽長度、各部位乾物重、相對生長速率(RGR)、葉片數、葉片大小及總葉面積等參數，以NH4(上標 +)-N/NO3(上標 -)-N混合比例為25/75及50/50處理者較施用單一氮源者為佳。而5種施肥處理苗木之葉面積比(LAR)及葉重比(LWR)均較高，比葉面積(SLA)則以完全施用NH4+-N之100/0處理最高(244.6平方公尺g^(-1))，對照組最低(138.0平方公尺g^(-1))。不同氮肥比例處理90天後，以25/75處理之苗木品質指數最高(0.43)，完全NH4(上標 +)-N之100/0處理最低，僅0.14。至於扡插苗之葉綠素a、b及總葉綠素濃度以75/25及100/0二種處理較高，對照組最低。完全施用NH4(上標 +)-N的100/0處理苗木葉部細胞TTC還原性最高，達18.41O.D.g^(-1)，然根部細胞TTC還原性則最低(4.63O.D.g^(-1))。N肥型態明顯影響水質及介質之pH值，係隨NO3(上標 -)-N比例增加而升高，隨NH4(上標 +)-N比例增加而下降。完全施用NO3(上標 -)-N時，水質及介質pH值分別升至7.07及7.58；完全施用NH4(上標 +)-N時，水質及介質pH值分別降至4.68及4.66；而混合二種氮源可使生長介質之pH值維持穩定狀態。
並列摘要
The study examined the effects of varying level of NH4(superscript +)-N/NO3(superscript -)-N ratio (0/0, 0/100, 25/75, 50/50, 75/25 and 100/0) on the growth, chlorophyll concentration, triphenyl tetrazolium chloride (TTC) reduction, and medium pH of Myoporum bontioides cuttings. Results indicated that 60 and 90 days after treatment, the sprout number, length, diameter, dry weights, relative growth rate (RGR), number, size and total area of leaves were high in NH4(superscript +)-N/NO3(superscript -)-N ratio being 25/75 and 50/50 than sole N forms. Cuttings grown at five fertilized treatments had high leaf area ratio (LAR) and leaf weight ration (LWA) than unfertilized treatment; however, the specific leaf area (SLA) was the highest (244.6 cm^2 g^(-1)) of cuttings cultivated in the 100% NH4(superscript +)-N. After 90 days of treatment, the Dickson Quality Index of cuttings was the highest (0.43) in NH4(superscript +)-N/NO3(superscript -)-N ratio being 25/75, and the lowest level of ammonium alone (100/0) was only 0.14. Concentrations of chlorophyll a and b, as well as the total amount of chlorophylls were high for cuttings fertilized with NH4(superscript +)-N/NO3(superscript -)-N ratio being 75/25 and 100/0, and the amount of chlorophylls was lowest in the 0/0 treatment. Cuttings grown at with only NH4 (superscript +)-N (100/0) had the highest TTC reduction of leaf tissue (18.41 O.D. g^(-1)), though the reduction in root tissue was the lowest (4.63 O.D. g^(-1)). The pH value of cultural medium was affected markedly by the nitrogen form, which was increased with increasing NO3 (superscript -)-N and decreased with increasing NH4(superscript +)-N nutrient solution. The water and medium pH values were reached 7.07 and 7.58 in the medium containing NO3(superscript -)-N alone, while they decreased to 4.68 and 4.66 with 100% NH4(superscript +)-N treatment. However, combined ammonium and nitrate nitrogen maintained a stable pH value.