摘要
对日光温室内栽培的五叶一心白菜分别叶面喷施2、5、10和15mmol·L-1亚硫酸氢钠(NaHSO3),以喷施清水为对照,分别在处理后0、4、8、12和16d测定植株生物量、叶片的硝酸盐含量(NO3-)和硝酸还原酶(Nitrate reductase,NR)活性,同时测定叶片的光合参数和叶绿素荧光参数。结果表明,10mmol·L-1NaHSO3处理后12d时的效应最为显著,与对照相比,叶片NO3-含量降低44.85%,NR活性提高51.26%,且株高和地上部干质量均明显增加;同时显著提高其净光合速率(Pn)、羧化效率(CE)、最大羧化速率(Vcmax)、PSⅡ的原初量子效率(Q)和最大电子传递速率(ETRmax)。由此说明,对白菜叶面喷施NaHSO3,一方面能够在一定程度上提高NR活性,拉动氮素的还原同化,降低NO3-的累积;另一方面能够通过提高PSⅡ电子传递能力和羧化反应速率,促进光合碳同化效率,可在碳骨架和能量供应上拉动氮代谢的还原同化。
The effects of sodium bisulfite（NaHSO3）on nitrate reduction and photosynthetic capacity were studied in the leaves of non-heading Chinese cabbage. It had been investigated the impact of 0（control）,2（S2）,5（S5）,10（S10）and 15（S15）mmol · L-1 NaHSO3 concentrations on plant biomass,nitrate content,nitrate reductive（NR）activity and photosynthetic capacity after spraying for 0,4,8,12,16 d in the 5 leaves stage of non-heading Chinese cabbage seedling. With the application of different NaHSO3 concentrations,the significant concentration effect and time effect were observed on plant biomass,NO3- content and NR activity in the leaves. However,the most significant effect was presented for the 12th day of S10 treatment comparing with control,in which not only did the NO3- content decrease by 44.85% and NR activity increase by 51.26%,but also the plant height and shoot dry weight distinctly increase. Moreover,the NaHSO3 dramatically increased net photosynthetic rate（Pn）, carboxylation efficiency（CE）,maximal carboxylation rate（Vcmax）,primary quantum efficiency of PSⅡ （Q）and maximal electron transport rate（ ETRmax）in leaves. Thereby,the NaHSO3 stimulated NR activity firstly,then drove assimilation of nitrate,and reduced nitrate accumulation finally;On the other hand, the positive action of NaHSO3 for anabolic metabolism of nitrogen was triggered by more production of carbon skeleton and energy supply mainly due to promotion of photosynthetic carbon assimilation efficiency,which improved by the increase of PSⅡ electronic transmission ability and carboxylation reaction rate.
出处
《园艺学报》
CAS
CSCD
北大核心
2012年第4期669-676,共8页
Acta Horticulturae Sinica
基金
河北省科技支撑计划项目(11220701D
11220711)
关键词
白菜
NAHSO3
硝酸盐还原
光合能力
氮硫代谢
non-heading Chinese cabbage
NaHSO3
nitrate reduction
photosynthetic capacity
nitrogen-sulfur metabolism
