Abstract: 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 morphologies 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 nitrogen 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 soluble 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 morphologies and physiological indices of nine sorghum cultivars were investigated in low-N(0.04 mmol/L) and normal-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, Zhuganqing 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.

Key words: Sorghum seedling, Nitrogen concentration, Morphology character, Physiological character

CLC Number: 

• S514.01

• Q945.78