氮钼肥配施对烤烟生长发育及氮组分积累的影响

为探明氮钼肥配施对烤烟光合碳同化及氮组分积累的影响机制，以烤烟品种K326为供试材料，分析了盆栽试验条件下不同氮钼肥配比对烤烟气体交换参数、各器官氮素分配、含氮化合物以及干物质积累等的影响。结果表明:①不同氮素水平下，增施钼肥能够显著提高叶片的光合速率，施钼肥处理分别较未施钼肥处理增加9.98%~58.00%（N₀）、0.86%~38.39%（N_0.15）、0.19%~30.17%（N_0.3）。②中、低氮素水平下，烟株氮素累积量随着施钼肥量的升高而增加，分别较对照增加24.68%~30.77%（N₀）、3.69%~43.47%（N_0.15），高氮素条件下，施钼肥处理的氮素积累量降低。③烤烟的干物质积累量以N_0.15Mo_0.3处理最高，氮、钼肥以及二者的互作效应对烟株干物质积累量增长的贡献率分别为50.60%、37.65%和11.75%。④干物质积累量、硝酸还原酶活性和游离氨基酸含量（质量分数）对烤后烟叶中总氮、烟碱含量变化的影响较为显著，通过合理的氮钼肥配施能够提高烟株光合碳同化能力，促进烟株氮素吸收与物质积累，进而调控烤后烟叶氮组分含量。 

Effects of combined application of nitrogen and molybdenum fertilizers on growth and nitrogen component accumulation of flue-cured tobacco

In order to explore the influence mechanism of combined application of nitrogen and molybdenum fertilizers on photosynthetic carbon assimilation and nitrogen component accumulation by flue-cured tobacco, using flue-cured tobacco cultivar K326 as the test material, the effects of nitrogen fertilizer to molybdenum fertilizer at different ratios on photosynthetic gas exchange parameters, nitrogen distribution in various organs, nitrogen compounds and dry matter accumulation by flue-cured tobacco were analyzed through pot experiments. The results showed that: 1) The photosynthetic rate of tobacco leaves was significantly improved by increasing the application of molybdenum fertilizer under different nitrogen levels. The net photosynthetic rate of molybdenum fertilizer treatment increased by 9.98% to 58.00% (N₀), 0.86% to 38.39% (N_0.15)and 0.19% to 30.17% (N_0.3), comparing with the treatments without molybdenum fertilizer. 2) The nitrogen accumulation of tobacco plants increased with molybdenum application amount under the moderate and low nitrogen levels, increased by 24.68% to 30.77% (N₀) and 3.69% to 43.47% (N_0.15)respectively as comparing with the treatments without molybdenum fertilizers. However, the nitrogen accumulation under the molybdenum treatment was decreased at high nitrogen level. 3)The dry matter accumulation in the treatment of N_0.15Mo_0.3 was the highest, and the contribution rates of nitrogen, molybdenum and their interaction were 50.60%, 37.65% and 11.75%, respectively. 4)The effects of dry matter accumulation, nitrate reductase activity and free amino acid contents on the changes of total nitrogen and nicotine contents in flue-cured tobacco leaves were significant. The ability of photosynthetic carbon assimilation, the nitrogen absorption and material accumulation could be improved by rational application of nitrogen and molybdenum fertilizers, the nitrogen component content(mass fraction)in cured tobacco leaves could be optimized.