甘蔗姊妹系对低钾胁迫响应的差异分析

以来源于同一甘蔗杂交组合的姊妹系‘粤糖55号’和‘粤糖00-236’为材料,通过对长期低钾胁迫下甘蔗生长、钾含量、钾利用效率和钾吸收效率以及短期低钾胁迫下钾含量、抗氧化酶活性变化的研究,探讨甘蔗姊妹系耐低钾能力的差异。研究结果显示：在长期低钾胁迫下,2个品种的株高、茎径和生物量存在显著差异,‘粤糖55号’表现出显著的下降,而‘粤糖00-236’仅根系生物量显著下降。2个品种的钾含量显著下降,‘粤糖00-236’下降幅度高于‘粤糖55号’,但是低钾胁迫下‘粤糖00-236’的钾利用效率和钾吸收效率均高于‘粤糖55号’。短时间低钾胁迫下,‘粤糖55号’根系钾含量在胁迫48 h后开始下降,而‘粤糖00-236’根系的钾含量在胁迫的24 h已经显著低于对照。‘粤糖55号’根系的MDA含量在胁迫48 h后显著上升,而‘粤糖00-235’则在胁迫的72 h显著上升。‘粤糖55号’的SOD和POD活性在低钾胁迫下表现为下降,而‘粤糖00-236’则在48 h后出现上升。由此可见,同一组合的甘蔗姊妹系在耐低钾胁迫能力上存在显著差异,提高钾的吸收、利用效率和根系抗氧化酶活性有助于提高甘蔗的耐低钾胁迫能力。

Different Responses to Low Potassium Stress Between Two Sugarcane Varieties from the Same Hybrid Combination

Two sugarcane varieties(YT55 and YT00-236)from the same hybrid combination were used to analyze the different responses to low potassium(K)stress.The growth parameters,K contents,K utilization and uptake effeciency under longterm low K stress,and the K contents,activites of antioxidative enzymes under shortterm low K stress were investigated.The results revealed that significant differences were found for height,diameter,biomass between the two varieties under longterm low K stress.The height,diameter,shoot and root biomass decreased significantly in YT55 under longterm low K stress,while only root biomass showed noticeable reduction in YT00-236.The K contents in shoots and roots of the two varieties decreased under longterm low K stress.The rate decrease of K content in YT55 was higher than that in YT00-236 under longterm low K stress,but the utilization effeciency and uptake effeciency in YT00-235 were higher than those in YT55.The K content in the roots of YT55 began to decrease after 48 h under low K stress,whereas significant reduction was found for K content in the roots of YT00-236 after 24 h under low K stress.The MDA content in the roots of YT55 showed significant increase after 48 h under low K stress,but after 72 h under low K stress in the roots of YT00-236.The activities of SOD and POD decreased under low K stress in roots of YT55,but notably increased after 48 h under low K stress in the roots of YT00-236.These results indicated that significant difference for low K tolerance existed between the varieties from the same hybrid combination.Improvement in K uti740 utilization and uptake effeciency and activities of antioxidative enzymes might help to increase the low K tolerance in sugarcane.