中国农业科学 ›› 2018, Vol. 51 ›› Issue (11): 2072-2083.doi: 10.3864/j.issn.0578-1752.2018.11.005

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

不均匀盐胁迫对紫花苜蓿生长特性的影响

熊雪1,2,罗建川3,魏雨其4,周冀琼4,张英俊1,4

 
  

  1. 1南京农业大学草业学院,南京 210095;2河北民族师范学院,河北承德 067000;3中国农业科学院草原研究所,呼和浩特 010010;4中国农业大学动物科技学院,北京 100094
  • 收稿日期:2017-10-30 出版日期:2018-06-01 发布日期:2018-06-01
  • 通讯作者: 张英俊,E-mail:zhangyj@cau.edu.cn
  • 作者简介:熊雪,E-mail:xiongxue1987@126.com
  • 基金资助:
    现代农业产业技术体系建设项目-牧草体系(CARS-34)

Effects of Non-Uniform Salt Stress on Growth Characteristics of Alfalfa

XIONG Xue1,2, LUO JianChuan3, WEI YuQi4, ZHOU JiQiong4, ZHANG YingJun1,4   

  1. 1College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095; 2Hebei Normal University for Nationalities, Chengde 067000, Hebei; 3Institute of Grassland Research of Chinese Academy of Agricultural Sciences, Huhhot 0100104College of Animal Science and Technology, China Agricultural University, Beijing 100094
  • Received:2017-10-30 Online:2018-06-01 Published:2018-06-01

摘要: 目的土壤中的盐分通常存在不均匀分布的现象。已有的研究发现与均一盐胁迫环境相比,不均匀盐胁迫可以缓解盐分对植物的伤害。研究旨在了解植物对不均匀盐分胁迫的响应,作为对均匀盐分下植物生理的一个重要补充,为扩大盐碱地的利用和栽培管理措施提供参考依据。【方法】采用分根装置将紫花苜蓿(Medicago sativa的根系分为两部分,设置无盐胁迫(0/0,各半根系所处环境NaCl浓度均为0)、半边根系环境NaCl浓度为0的不均匀盐胁迫系列(0/S:0/100、0/150、0/200和0/250)、半边根系NaCl浓度为50 mmol·L-1的不均匀盐胁迫系列(50/S:50/100、50/150、50/200和50/250)以及两半根系环境NaCl浓度相同的均一盐胁迫系列(S/S:50/50、100/100、150/150、200/200和250/250)处理(“/”两边数值代表各半根系所处环境的盐胁迫状况,以NaCl浓度mmol·L-1表示)。处理15 d后测定其植株生长速率、生物量、水分吸收、钠、钾离子浓度、丙二醛含量等指标,了解不同盐胁迫环境对紫花苜蓿生长的影响。【结果】盐胁迫抑制紫花苜蓿生长,植株生长速率、生物量、水分吸收下降,叶绿素含量降低,脯氨酸含量升高,膜质过氧化程度加大,叶片Na+浓度升高,K+浓度降低,表现为较低的K+/Na+。而不均匀盐胁迫0/S与50/S处理与均匀高盐处理S/S相比,植株生长速率和地上生物量分别增加了57.05%—369.34%和15.47%—42.57%,Na+浓度降低了15.85%—55.93%,缓解了Na+的毒害作用。且不均匀盐胁迫下70%—92%的水分吸收来自于无盐或低盐胁迫一侧根系,增加了整株植物的水分吸收。【结论】不均匀盐胁迫处理与均匀的高盐胁迫处理相比,增加了紫花苜蓿叶绿素含量,降低了膜质过氧化程度,通过调控Na+与K+的吸收维持叶片中相对较高的K+/Na+,并且无盐和低盐胁迫一侧根系表现出补偿性吸水和补偿性生长,进而促进了植物生长,增加了地上和地下生物量。在一定的浓度范围内,与均匀的高盐胁迫处理相比,不均匀盐胁迫环境下植株根系所处环境的盐分浓度差异越大其对盐害的缓解作用越显著。

关键词: 紫花苜蓿, 不均匀盐胁迫, 分根, 植株生长, 钾钠比

Abstract:

ObjectiveSoil salinity is often non-uniform in salt fields. Previous studies found that non-uniform salt stress could alleviate salt damage to plants compared to uniform salt treatment. The study on the response of alfalfa under non-uniform saltinity was an important supplement to plant physiology under uniform saltinity, so as to provide references for cultivation and management in salt fields.【Method】The root system of alfalfa was divided into two parts, including salt free treatment (0/0, NaCl concentrations were zero in both root systems), non-uniform salt stress with a NaCl concentration of zero in one side of the roots (0/S: 0/100, 0/150, 0/200, 0/250), non-uniform salt stress with a NaCl concentration of 50 in one side of the roots (50/S: 50/100, 50/150, 50/200, 50/250) and uniform salt stess (S/S: 50/50, 100/100, 150/150, 200/200, 250/250 ) treatments ( “/” on both sides represent different salt stress concentrations, indicated by NaCl concentration mmol·L-1). After treatments for 15 days, the plant growth rate, biomass, water uptake, sodium and potassium ion concentration and malondialdehyde content were measured, and the effects of non-uniform salt stress on the growth characteristics of alfalfa were studied.【Result】Salt stress inhibited the growth of alfalfa, and the plant growth rate, biomass, water uptake decreased, chlorophyll contents declined, proline contents increased, membrane lipid peroxidation aggravated, Na+ concentrations increased, K+ concentrations decreased, showed a lower K+/Na+ ratio. Compared with the uniform high salt S/S treatments, the plant growth rate and aboveground biomass of 0/S, 50/S treatments increased by 57.05%-369.34% and 15.47%-42.57%, respectively, and the Na+ concentrations decreased by 15.85%-55.93%, alleviating the toxic effect of Na+. And 70%-92% water uptake from non-uniform salt stress came from the no-saline or low-saline part, increased water uptake of the whole plant.【Conclusion】The non-uniform salt stress treatments with a higher K+/Na+ increased the chlorophyll contents of alfalfa and decreased the degree of membrane lipid peroxidation compared with the uniform salt stress treatments. The no-saline or low-saline part showed compensated water uptake and the compensatory growth of the roots, which promote the growth of plants, increase the shoot and root biomass. The more difference between the two sides of the roots, the effects on relieve salt damage were more obvious.

Key words: alfalfa (Medicago sativa), non-uniform salt stress, split-root, plant growth, K+/Na+