遮荫下氮肥用量对雪茄外包皮烟叶光合特性的调控效应

通过遮荫条件下的盆栽试验,测定分析了4个氮肥处理的雪茄外包皮烟叶片的叶绿素含量、净光合速率和叶绿素荧光动力学参数,探讨了不同氮肥用量对雪茄外包皮烟叶光合特性的调控效应。结果表明,随着氮肥用量的增加,烟叶的叶绿素含量增加,叶片的PS.II最大光化学效率和潜在活性,PSⅡ的实际光化学效率以及荧光光化学猝灭系数(qP)都有增加的趋势,最终导致叶片净光合速率的提高。试验还表明,适当的增施氮肥有利于改善叶片的光合功能,提高叶片的净光合速率,但过量氮肥则不利于光合能力的改善,更不利于荧光动力学参数的优化。

Response of photosynthetic characteristics in leaves of cigar wrapper tobacco to nitrogen application under shady condition

Chlorophyll contents,net photosynthetic rates and chlorophyll fluorescence parameters of the cigar wrapper tobacco leaves were measured to study the response of photosynthetic characteristics to different N application rate under shady condition.The results showed that the chlorophyll contents of tobacco leaves were increased with the increasing rate of nitrogen,so did the PSII potential activity,the maximal photochemical efficiency of PSII,and photochemical quenching coefficient(qP) in tobacco leaves,consequently the net photosynthetic rates were enhanced.The results of experiments also showed that optimum application of N could improve the photosynthetic capability of tobacco leaves and increase the net photosynthetic rates,but over-application of N had a negative influence on photosynthetic capability and an even worse effect on the photochemical quenching coefficient and ΦPSII.