曾巧英　吴嘉云　冯晓敏　张南南　吴自林　齐永文

摘  要：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則在胁迫的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。

关键词：甘蔗;低钾胁迫;钾含量;抗氧化酶活性

中图分类号：S566.1      文献标识码：A

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

ZENG Qiaoying， WU Jiayun， FENG Xiaoming， ZHANG Nannan， WU Zilin， QI Yongwen*

Guangdong Key Lab of Sugarcane Improvement and Biorefinery / Guangzhou Sugarcane Industry Research Institute， Guangzhou， Guangdong 510316， China

Abstract： 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 utilization and uptake effeciency and activities of antioxidative enzymes might help to increase the low K tolerance in sugarcane.

Keywords： sugarcane; low K stress; K content; activities of antioxidative enzymes

DOI： 10.3969/j.issn.1000-2561.2021.03.019

甘蔗是我国重要的糖能兼用作物，主产于广东、广西、云南和海南4省（区）。这4个省份的土壤为典型的红壤，受土壤的形成和气候条件影响，甘蔗主产区的土壤中有效钾往往缺乏[1]。由于甘蔗的生物量高，在甘蔗生长期内需要吸收大量的钾元素以满足其生长的需要，据估计，每生产1 t甘蔗大约需要吸收1～2.5 kg的K2O[2]。……