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作 者 ：王丽梅，胡琳莉，朱永超，董爱玲，廖伟彪，张国斌，郁继华*

期 刊 ：西北植物学报 2016年 8期 页码：1615~1622

关键词：小型大白菜；弱光；一氧化氮；光合作用参数；叶绿素荧光参数；

Keywords:Brassica pekinensis, low light intensity, nitric oxide, photosynthetic characteristics, chlorophyll fluorescence,

摘 要 ：以水培的小型大白菜幼苗为材料，在前期筛选的总氮浓度（5 mmol/L）、铵硝配比（10∶90）和中度弱光（95~105 μmol·m^-2·s^-1）条件下，测定一氧化氮供体（硝普钠，SNP）、抑制剂(L NAME、NaN₃)和清除剂(Hb)处理8 d后小型大白菜幼苗形态指标及光合荧光参数，探讨外源NO参与铵硝营养缓解小型大白菜幼苗遭受弱光胁迫的效应。结果显示：（1）在弱光胁迫条件下，单独SNP、铵硝比液加SNP处理后小型大白菜幼苗地上地下部鲜重、叶面积均与对照CK差异不显著，说明SNP、铵硝比液加SNP 处理均可以促进弱光下小型大白菜幼苗的生长，缓解弱光胁迫伤害。（2）铵硝比液中添加NO抑制剂(L NAME、NaN₃)和NO清除剂(Hb)后，小型大白菜幼苗叶面积、地上地下部鲜重、净光合速率(P_n)、气孔导度（G_s）、PSⅡ最大光量子产量(F_v/F_m)以及光合电子传递速率(ETR)均不同程度地降低，如L NAME、NaN₃和Hb处理的叶面积较CK分别显著减小15%、24%和40%，其P_n则分别显著减小31.2%、35.8%和56.7%。研究表明，添加NO抑制剂和清除剂处理降低了铵硝营养在弱光下对小型大白菜幼苗生长的缓解效果，从而证明NO参与了铵硝营养缓解弱光胁迫对小型大白菜幼苗光合作用的影响。

Abstract:Under the early filtered total nitrogen 5 mmol/L, ammonium: nitrate (10∶90) and moderate low light level, hydroponic mini Chinese cabbage seedlings was employed to study NO donor, inhibitor(L NAME，NaN₃) and scavenger(Hb) conducted for 8 days. The morphological parameters and photosynthesis fluorescent parameters of mini Chinese cabbage seedlings were measured. To probe exogenous NO involved in the ammonium and nitrate regulation of mini Chinese cabbage seedlings growth under low light intensity stress. The results indicated that: (1) plants supplied with SNP compared with CK increased chlorophyll content，but had no significant difference in fresh weight of shoot and root，total leaf area, the photosynthetic characteristics and chlorophyll fluorescence parameters. (2) When the NO scavenger (Hb) and inhibitor(L NAME, NaN₃) were added into the ammonium nitrate solution, the shoot and root of fresh weight, total leaf areas, net photosynthetic rate(P_n), stomatal conductance(G_s), maximum quantum yield of PSⅡ(F_v/F_m), electron transport rate(ETR) of plants decreased in different levels. Compared with CK, total leaf area decreased 15%, 24% and 40%, Pn declined 31.2%, 35.8% and 56.7%. Taken all together, NO scavenger and inhibit can obviously eliminate the promotion effect of moderate ammonium: nitrate in mini Chinese cabbages seedling growth under low light intensity. Moreover, exogenous NO has the same function with moderate ammonium: nitrate, which can promote the growth of mini Chinese cabbage seedling under low light intensity stress. Therefore, NO involved in the moderate ammonium: nitrate(10: 90) promotion of photosynthetic characteristics of mini Chinese cabbages seedlings under low light intensity stress.

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