Acta Agrestia Sinica ›› 2023, Vol. 31 ›› Issue (6): 1762-1771.DOI: 10.11733/j.issn.1007-0435.2023.06.019

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Effects of Drought Stress on Growth and Chlorophyll Fluorescence Characteristics of Medicago sativa L.

YU Si-min, LUO Yong-zhong, KANG Fang-ming, QIU Ying-de, LI Zhuan-tao   

  1. College of Forestry, Gansu Agricultural University, Lanzhou, Gansu Province 730070, China
  • Received:2022-11-09 Revised:2023-02-13 Online:2023-06-15 Published:2023-06-30

干旱胁迫对紫花苜蓿生长和叶绿素荧光特性的影响

于思敏, 罗永忠, 康芳明, 邱应德, 李转桃   

  1. 甘肃农业大学林学院, 甘肃 兰州 730070
  • 通讯作者: 罗永忠,E-mail:493517987@qq.com
  • 作者简介:于思敏(1997-),女,蒙古族,内蒙古赤峰人,硕士研究生,主要从事植物抗旱生理研究,E-mail: 2635147606@qq.com
  • 基金资助:
    国家自然科学基金项目(32160409)资助

Abstract: To investigate the growth,photochemistry characteristics,and the relationship between them of alfalfa (Medicago sativa L.) under different drought stress,M. sativa L. 'Zhongmu No.1’ and M. sativa L. 'Zhongtian No.1’ were used as the materials. The plant height,basal stem diameter and chlorophyll fluorescence parameters of alfalfa under different drought stresses were measured at different times after water stress. The results showed that except for mild drought,the growth rate of alfalfa slowed downward with the increasing drought stress,while initial fluorescence (Fo) and Non-photochemical quenching (NPQ) gradually increased and other fluorescence parameters gradually decreased. The growth rate of plant height and basal stem diameter were negatively correlated with Fo and NPQ. The drought stress inhibited the photochemical activity of Photosystem Ⅱ complex (PSⅡ) and increased thermal dissipation,which affected photosynthesis in alfalfa and eventually led to growth inhibition. Mild drought didn’t inhibit the growth of alfalfa and promoted the plant height of 'Zhongtian No.1’. With increasing drought stress and time,the basal stem diameter,Fo,potential photochemical efficiency (Fv/Fo),maximal photochemical efficiency (Fv/Fm) showed cultivars specificities,'Zhongmu No.1’ were more resistant to drought. The results should provide some theoretical reference for further mastering the drought-resistance mechanism of alfalfa and the selection and breeding of drought-resistant cultivars.

Key words: Alfalfa, Drought stress, Growth rate, Chlorophyll fluorescence characteristics, Cultivars specificity

摘要: 为探明干旱条件下紫花苜蓿(Medicago sativa L.)的生长和光化学特性变化规律及二者的关系,以'中苜1号’(M. sativa L. 'Zhongmu No.1’)和'中天1号’(M. sativa L. 'Zhongtian No.1’)为材料,采用盆栽控水方法,于不同控水时间测定不同干旱条件下紫花苜蓿的株高、基径及叶绿素荧光参数。结果表明:除轻度干旱外,随着干旱胁迫的加剧,苜蓿生长速率减缓且减缓程度逐渐增大。初始荧光(Fo)和非光化学淬灭系数(NPQ)逐渐上升,其他荧光参数均逐渐下降。株高和基径的生长速率与FoNPQ极显著负相关,干旱胁迫使光系统Ⅱ(PSⅡ)光化学活性降低,热耗散增加,影响苜蓿光合作用,最终导致其生长受到抑制。轻度干旱未抑制2种苜蓿的生长且促进了'中天1号’株高的生长。随着干旱加剧和持续时间延长,基径、Fo、潜在光化学效率(Fv/Fo)、最大光化学效率(Fv/Fm)表现出品种特异性,'中苜1号’的抗旱性更强。该结果为探究紫花苜蓿抗旱机制及抗旱品种选育提供理论参考。

关键词: 紫花苜蓿, 干旱胁迫, 生长速率, 叶绿素荧光特性, 品种特异性

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