不同氮浓度对高粱幼苗形态及生理特征的影响

摘要

为了给高粱耐低氮分子机制研究提供理论参考依据，以耐瘠程度不同的高粱品种为材料，采用水培法研究了6个氮浓度对高粱幼苗形态及生理特征的影响。结果表明，高粱幼苗地下干质量和POD活性在不同氮浓度间无显著性差异；氮浓度为4 mmol／L时，株高、茎粗、生长速度、干质量、叶绿素含量、可溶性蛋白和SOD活性最大；氮浓度为0．04 mmol／L时，高粱幼苗缺氮表现明显，株高、茎粗、成活叶数、干质量、叶绿素含量和可溶性蛋白含量较氮浓度为4 mmol／L时显著降低，根冠比显著升高；氮浓度大于4 mmol／L时，除成活叶数和根冠比外，其他指标值均下降。以0畅04 mmol／L为低氮处理，4 mmol／L为正常氮处理，对9个高粱品种的形态和生理指标进行测定，聚类分析显示，耐低氮材料为晋杂12号，中等耐低氮材料为狼尾巴、二达芒和八月齐，低氮敏感型材料为小铜锤、关东黄、农858、竹竿青和西藏。%The objective of this study was to discuss the variations of morphologies and physiological indices of sorghum seedlings under the different nitrogen concentration ,and to give some reference evidences for the study on molecular mechanism of sorghum low-nitrogen tolerance .With different sorghum varieties to low fertility tolerant as materials,a solution culture experiment was carried out to study the effects of six nitrogen concentrations on the mor -phologies and physiological indices of sorghum seedlings .The results showed that the difference of dry weight of root and POD activity of sorghum seedlings was no significant difference among six nitrogen concentrations .When the ni-trogen concentration was 4 mmol/L,the plant height ,stem diameter ,rate of growth ,dry weight of root and shoot , chlorophyll and soluble protein contents , and SOD activity were maximum;while the nitrogen concentration was 0.04 mmol/L,the plant height ,stem diameter,alive leaf number ,dry weight of root and shoot ,chlorophyll and solu-ble protein content significantly decreased , root-canopy ratio markedly increased .when the nitrogen concentration was greater than 4 mmol/L,all indicators except alive leaf number and root-canopy ratio decreased;And the mor-phologies and physiological indices of nine sorghum cultivars were investigated in low -N(0.04 mmol/L) and nor-mal-N(4 mmol/L ),the results of cluster analysis showed that Jinza 12 was a low-N tolerance cultivar,Langweiba, Erdamang and Bayueqi were middle low-N resistance varieties ,while Xiaotongchui ,Guandonghuang ,Nong 858 ,Zhu-ganqing and Xizang were low-N sensitive cultivars.So the nitrogen concentration (4,0.04 mmol/L)were right for screening low N-tolerance cultivars at sorghum seedling stage .