低pH条件下钾对液培甘蔗幼苗生长及根系形态的影响

摘要

A hydroponic experiment was conducted to investigate the effect of different potassium levels (0.1, 3 and 6 mmol/L) on the growth and the root morphology of sugarcane seedling under low pH. The results showed that, under 0.1 mmol/L potassium level in the low pH (4.0) of nutrient solution, the dry matter and the plant height decreased; the total length, average diameter, total average superficial area and total volume of the roots significantly decreased; the root activity and potassium content in plant also decreased, and the root-shoot ratio increased. The seedling returned to normal growth when the potassium level increased to 3 mmol/L, while both the total length and the total volume decreased at 6 mmol/L potassium level, which were harmful to the root normal growth.%本研究采用液培方法模拟在低pH条件下，不同钾水平(0.1、3、6 mmol/L)对甘蔗幼苗生长及根系形态的影响。研究结果表明，在低pH液培条件下供钾不足时(0.1 mmol/L)，甘蔗幼苗干物质量下降，株高降低，根冠比增大，根系形态参数包括根总长、根平均直径、根总表面积与根总体积均显著减小，根系活力下降，植株钾含量降低。当钾水平提高到3 mmol/L时则可以恢复正常生长，但当钾水平继续升高到6 mmol/L时则会减少根总长与根总体积，对根系生长不利。