小白菜硝态氮、氨基酸态氮的吸收动力学差异  

The Difference of Uptake Kinetics of Nitrate,Amino acids by Pakchoi(Brassica chinensis)

作　　者：王小丽[1] 杨丹妮[1] 叶俊[1] 黄丹枫[1] 

机构地区：[1]上海交通大学农业与生物学院,上海200240

出　　处：《土壤通报》2012年第6期1361-1365,共5页Chinese Journal of Soil Science

基　　金：上海市科委安全项目(09391910400);上海市农委项目(沪农推字20090102);农业部行业项目(200903056);上海市蔬菜学重点学科(B209)资助

摘　　要：采用无菌溶液培养试验,研究了两个小白菜品种(‘金申’与‘五月慢’)对硝态氮(NO3--N)、甘氨酸态氮(Gly-N)吸收的动力学规律,以及NO3--N对Gly-N吸收动力学参数的影响。结果表明,两个小白菜品种对不同氮源的吸收都符合米氏方程,具有主动吸收的特征,Vmax及1/Km值均为NO3-N>Gly-N,Gly-N吸收的Vmax及1/Km值‘金申’大于‘五月慢’。NO3--N的存在抑制了小白菜Gly-N的吸收速率、Vmax及1/Km值,其中品种‘五月慢’Gly-N吸收的Vmax下降显著,品种‘金申’下降不显著。常规水培10 d后,小白菜干重、氮积累量对NO3--N与Gly-N处理表现显著差异,均为NO3--N>Gly-N。品种间差异显著,Gly-N处理下‘金申’干重及氮积累量显著大于‘五月慢’。综上,小白菜对于有机、无机态氮的吸收能力存在基因型差异,‘金申’品种较‘五月慢’品种更能适应有机氮源的培养环境。Uptake kinetics of NO3--N and Gly-N by pakchoi（Brassica chinensis）,also the effect of NO3--N to Gly-N uptake,were studied under hydroponics conditions.The results indicated that uptake kinetics of different nitrogen forms by two pakchoi cultivars（＇Jinshen＇ and ＇Wuyueman＇）accorded with Michaelis-Menten equation.The kinetics parameters,maximum uptake rate（Vmax） and the affinity（1/Km） of NO3--N uptake were greater than those of Gly-N uptake,and the kinetics parameters of Gly-N uptake were greater in Jinshen than in Wuyueman.The uptake rate,maximum uptake rate（Vmax） and the affinity（1/Km） of Gly-N uptake were inhibited by the existence of NO3--N,and there were significant decrease of Vmax in Wuyueman,but no significant decrease of Vmax in Jinshen.Significant differences in dry biomass and N accumulation were found in treatments 10 d,the order was NO3--NGly-N.Significant differences were also observed between the two pakchoi cultivars.Dry biomass and N accumulation of ＇Jinshen＇were higher than that of ＇Wuyueman＇in treatment Gly-N.The results showed the difference of N uptake between pakchoi cultivars,and Jinshen may prefer to organic nitrogen source than Wuyueman.

关 键 词：小白菜 硝态氮 氨基酸 吸收动力学 

分 类 号：S636.9[农业科学—蔬菜学] S311[农业科学—园艺学]