采用盆栽试验，通过测定烤烟成熟过程中叶片硝酸还原酶 (NR) 和转化酶 (Inv) 活性，研究了无机氮肥的追期和追量对烟叶成熟过程中叶片碳氮代谢强度及转化的影响，结果显示：在上、下部叶片成熟过程中，NR和Inv活性下降；随追氮时期推迟或追氮量增加，下部叶NR和Inv活性提高，Inv/NR降低，Inv／NR曲线峰值延后；在移栽后30d内或追氮量低于总施氮量30％时，随追氮时期推迟或追氮量增加，上部叶NR活性、Inv活性、Inv／NR降低。在本试验条件下，于移栽后30 d追肥，追氮量30％，最有利于上、下部叶成熟过程中碳氮代谢的协调和适时转化。

The biological properties on tobacco with 35S: BnDREB1-5 transformation were analyzed which included the holding water capacity, the size and density of upper and lower epidermis stomata, the content of chlorophyll, and plasma membranes permeability after physical drought stressed 7h. The results indicated that water-holding capacity of 35S: BnDREB1-5 transgenic tobacco leaves was 62% higher than wild-types. The upper epidermis stomata apparatus was bigger in transgenic tobacco than wild-type, but the opening of stoma was smaller in upper epidermis than wild-types. The stomata density was 1. 5 times in wild-type leaves as large as in transgenic leaves. The content of chlorophyll was 29% higher in leaves of wild-type than in transgenic leaves, and the plasma membranes permeability were 1. 4 times in wild-type leaves as large as in transgenic tobacco.

通过大田试验, 研究了不同氮素形态及配比对烤烟叶片中谷酰胺合成酶(GS)、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)活性及烟碱、还原糖含量的影响、结果表明, 在移栽后85 d至采收结束, 1’2(纯施NH4-N)烟叶中的GS和SPS一直保持相对较高的水平；在移栽后91 d, 其烟碱含量是T1(纯施NO3-N)的1.2倍、13(NO3-N：NH4-N的质量比为1: 1)的1.1倍。还原糖含量是T1的0.4倍、13的0.6倍、T1有利于还原糖的积累；13有利于碳氮代谢的协调进行、

Net photosynthetic rate (PN) of tobacco plants grown with NH4-N as the only N source was the lowest all the times, while PN grown only with NO3-N was the greatest until 22nd day, and PN grown with both NO3-N and NH4-N (1: 1) was the greatest. Maximal photochemical efficiency of photosystem 2 (PS2), Fv/Fm, and actual quantum yield of PS2 under actinic irradiation (ΦPS2) in plants grown with only NH4-N were greatest at early stage and then decreased and were smaller than those of other treatments. Photochemical quenching coefficient (qP) and non-photochemical quenching coefficient (qNP) in the NH4-N plants were the greatest at all times. Hence excessive NH4-N can decrease not only photochemical efficiency but also the efficiency of utilization of photon energy absorbed by pigments for photosynthesis. Therefore, excessive NH4-N is a hindrance to photosynthesis of flue-cured tobacco. On the other hand, tobacco cultured with an appropriate mixture of NO3-N with NH4-N can sufficiently utilize photon energy and increase the efficiency of energy transformation.