低氮条件下NaCl浓度对大麦氮素吸收利用的影响

Effects of NaCl concentrations on nitrogen uptake and utilization of barley under low nitrogen conditions

为了探讨低氮条件下耐盐大麦种质资源对氮素吸收利用的规律,本文以大麦品种‘花30’诱变结合小孢子培养获得的耐盐纯合新品系DH20和‘花30’(亲本对照)为材料,通过幼苗水培对相关性状进行测定分析。结果表明:在无盐条件下,低氮较正常氮处理水平均降低了DH20和‘花30’的苗高、地上部干重、氮素积累量、气孔导度、叶绿素荧光参数,但无显著差异;在中盐(150 mmol·L^(-1)NaCl)条件下,低氮处理对新品系DH20的苗高、地上部干重、氮素积累量、氮素吸收利用率、氮素利用率、净光合速率、气孔导度、Fv’/Fm’值的影响均显著低于对‘花30’各相应性状的影响;在高盐(450 mmol·L^(-1)NaCl)条件下,DH20和‘花30’的苗高、干重、氮素积累量和氮素吸收利用率均很低,但无显著差异。经对大麦氮代谢关键基因表达分析发现,在低氮+中盐处理的条件下,DH20的HvNR1、HvNRT3.1和HvNRT3.3等氮利用基因表达量显著增加,促进幼苗对氮的吸收利用。说明耐盐大麦新品系DH20在中盐胁迫条件下具有对氮素高效吸收和利用的潜在能力,可以作为大麦育种中氮素高效利用的重要基因资源。

To investigate the nitrogen absorption and utilization by salt-tolerant barley germplasm under the salt-stress conditions,the relevant traits under the hydroponic conditions were analyzed using a newly derived line DH20 seedlings from the barley parental variety‘Hua30’by the combination of mutagenesis and microspore culture and the variety‘Hua30’(parental control)as the experimental materials.Results showed that the seedling length,above-ground dry matter weight,nitrogen accumulation,stomatal conductance,and chlorophyll content of the new line DH20 and the control‘Hua30’were reduced under the low nitrogen+zero salt treatment,but no significant differences were detected.Under medium salt(150 mmol·L^(-1)NaCl)conditions,the effects of low nitrogen treatment on the seedling length,above-ground dry matter weight,nitrogen accumulation,nitrogen uptake efficiency,nitrogen utilization rate,net photosynthetic rate,stomatal conductance,and Fv’/Fm’values of DH20 were significantly lower than those of‘Hua30’.Under low nitrogen+high salt treatment,the seedling length,dry matter weight,nitrogen accumulation,nitrogen uptake efficiency of DH20 and‘Hua30’were very low,but had no significant differences.Further analyses of the key nitrogen metabolism-associated genes(HvNR1,HvNRT3.1 and HvNRT3.3)in barley showed their significantly increased expression in DH20 under the low nitrogen+medium salt treatment,suggesting efficient absorption and utilization of nitrogen.These results indicated that the new salt-tolerant barley line DH20 had a potential for efficient absorption and using nitrogen under the condition of medium salt stresses,and could be used as an important genetic resource(or future variety)in barley breeding for efficient nitrogen utilization.