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草业学报 ›› 2024, Vol. 33 ›› Issue (6): 175-186.DOI: 10.11686/cyxb2023281

• 研究论文 • 上一篇    

硝酸铈与脱落酸处理对紫花苜蓿种子萌发和幼苗生理特性的影响

高金柱(), 赵东豪, 高乐, 苏喜浩, 何学青()   

  1. 西北农林科技大学草业与草原学院,陕西 杨凌 712100
  • 收稿日期:2023-08-09 修回日期:2023-09-27 出版日期:2024-06-20 发布日期:2024-03-20
  • 通讯作者: 何学青
  • 作者简介:E-mail: hexueqing@nwsuaf.edu.cn
    高金柱(1997-),男,河南洛阳人,在读硕士。E-mail: 2267173143@qq.com
  • 基金资助:
    国家重点研发计划项目(2022YFD1300803);大学生科技创新项目(S202210712379)

Effects of cerium nitrate and abscisic acid treatment on alfalfa seed germination and seedling physiological characteristics

Jin-zhu GAO(), Dong-hao ZHAO, Le GAO, Xi-hao SU, Xue-qing HE()   

  1. College of Grassland Agriculture,Northwest A&F University,Yangling 712100,China
  • Received:2023-08-09 Revised:2023-09-27 Online:2024-06-20 Published:2024-03-20
  • Contact: Xue-qing HE

摘要:

为研究稀土铈(Ce)与外源脱落酸(ABA)处理对紫花苜蓿种子萌发和幼苗生理特性的影响,采用浓度分别为5、10、20 μmol·L-1的硝酸铈、ABA及硝酸铈和ABA(1∶1)的混合溶液处理苜蓿种子进行发芽试验,探究其对种子的萌发、生长,幼苗的叶绿素含量、抗氧化酶活性和渗透调节物质含量等指标的影响。结果表明:5~10 μmol·L-1硝酸铈处理刺激了紫花苜蓿种子的萌发,并增大了根粗(5~20 μmol·L-1);而ABA(5~20 μmol·L-1)抑制了种子萌发和幼苗生长,且与硝酸铈混合处理解除了硝酸铈对根粗的膨大作用。硝酸铈可以缓解ABA对叶绿素含量的降低,并降低幼苗叶抗氧化酶活性,而Ce与ABA混合处理可显著提高紫花苜蓿幼苗的抗氧化酶活性。因此,硝酸铈处理对紫花苜蓿萌发及生长有一定的积极作用;硝酸铈与 ABA 混合处理时,ABA 在调节紫花苜蓿种子萌发和幼苗生长过程以及生理特性中发挥主导作用,硝酸铈+ABA处理的幼苗高抗氧化活性,表明幼苗受到胁迫。研究结果为稀土铈和ABA对紫花苜蓿萌发期的影响提供了参考。

关键词: 紫花苜蓿, 硝酸铈, 脱落酸, 种子萌发, 抗氧化性

Abstract:

This research studied the effect of rare earth cerium (Ce) and exogenous abscisic acid (ABA) treatment on seed germination and seedling physiological characteristics of alfalfa. Cerium nitrate, ABA, and cerium nitrate and ABA (1∶1) mixed solutions with concentrations of 5, 10, and 20 μmol·L-1 were used to treat alfalfa seeds to conduct germination tests and explore the impact on seed germination, growth, seedling chlorophyll content, antioxidant enzyme activity, and contents of osmoregulation substances in seedlings. It was found that cerium nitrate treatment at 5 and 10 μmol·L-1 significantly stimulated the germination index of alfalfa seeds (but not germination percentage) and all three concentrations of cerium nitrate (5-20 μmol·L-1) increased seedling root diameter. Meanwhile, ABA at all three concentrations (5-20 μmol·L-1) inhibited seed germination index and root and hypocotyl length. The mixed treatment of cerium nitrate+ABA had similar effects to those of ABA alone except that ABA neutralized the effect of cerium nitrate on root diameter and seedling suppression effects of ABA tended to be exacerbated by cerium nitrate at the higher concentration of 20 μmol·L-1. ABA decreased seedling chlorophyll content but the ABA effect was partially neutralized by addition of cerium nitrate. ABA generally did not change the antioxidant enzyme activity of seedling leaves, but the mixed treatment of Ce and ABA at the higher concentration of 20 μmol·L-1 resulted in significantly increased antioxidant enzyme activity of alfalfa seedlings. Therefore, cerium nitrate treatment has a partial positive effect on the germination and growth of alfalfa; When cerium nitrate is mixed with ABA, ABA plays a dominant role in regulating the germination and seedling growth processes as well as physiological characteristics of alfalfa. The high antioxidant activity of seedlings treated with cerium nitrate+ABA seems to indicate that the seedlings are under stress. This study provides a reference for the effect of rare earth cerium and ABA on the germination period of alfalfa.

Key words: alfalfa, cerium nitrate, abscisic acid, seed germination, antioxidant activity