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草业学报 ›› 2022, Vol. 31 ›› Issue (10): 110-121.DOI: 10.11686/cyxb2021492

• 研究论文 • 上一篇    

内生真菌对盐胁迫下紫花针茅种子萌发和幼苗生长的研究

张鹏(), 任茜, 孟思宇, 魏小星, 鲍根生()   

  1. 青海省青藏高原优质牧草种质资源利用重点实验室,青海大学畜牧兽医科学院,青海 西宁 810016
  • 收稿日期:2021-12-28 修回日期:2022-03-21 出版日期:2022-10-20 发布日期:2022-09-14
  • 通讯作者: 鲍根生
  • 作者简介:E-mail: baogensheng2008@hotmail.com
    张鹏(1996-), 男, 甘肃平凉人, 在读硕士。E-mail: zpkyw1314@163.com
  • 基金资助:
    青海省科技创新平台建设专项“青藏高原草种质资源创新与利用服务平台”(2021-ZJ-T01);国家自然科学基金项目(32060398);青海省“昆仑英才·高端创新创业人才”计划项目资助

Effects of Epichloё endophyte on seed germination and seedling growth of Stipa purpurea under salt stress

Peng ZHANG(), Xi REN, Si-yu MENG, Xiao-xing WEI, Gen-sheng BAO()   

  1. Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau,Qinghai Academy of Animal Science and Veterinary Madicine,Qinghai University,Xining 810016,China
  • Received:2021-12-28 Revised:2022-03-21 Online:2022-10-20 Published:2022-09-14
  • Contact: Gen-sheng BAO

摘要:

紫花针茅是青海湖流域盐渍化危害严重的高寒草地优势禾草之一,天然草地中紫花针茅保持较高的内生真菌侵染率,内生真菌侵染能提高禾草耐盐能力,然而有关盐胁迫下,内生真菌提高紫花针茅种子萌发和幼苗生长的研究鲜有报道。以带菌(E+)和不带菌(E-)的紫花针茅种子为研究对象,研究不同浓度的单盐(NaCl、Na2SO4、Na2CO3、NaHCO3)和复合盐(NaCl+Na2CO3)胁迫对E+和E-种子萌发和幼苗生长的影响。结果表明:随盐浓度增加,紫花针茅种子发芽率、发芽势和发芽指数不断降低,而内生真菌的存在抑制了其下降趋势;幼苗和胚根生长抑制强度随盐浓度增加,且种子萌发相对盐害率也持续增加。Na2CO3和Na2SO4对紫花针茅种子萌发和幼苗生长产生的盐害较强。由此可见,内生真菌侵染是紫花针茅适应青海湖流域盐渍化土壤且成为高寒草原优势禾草的原因之一,这将为利用内生真菌-紫花针茅共生体进行盐碱地改良和耐盐禾草种质创新奠定了理论基础。

关键词: 盐胁迫, 盐类型, 内生真菌, 紫花针茅, 发芽, 幼苗生长, 相对盐害率

Abstract:

Stipa purpurea is one of the dominant grass species in alpine grassland in the Qinghai Lake basin, which is severely affected by salinity. S. purpurea maintains a high rate of Epichloё endophyte infection in native grassland, and Epichloё endophyte infection can improve salt tolerance of grasses. However, little research has been reported on Epichloё endophyte effects on the seed germination and seedling growth of S. purpurea under salt stress. This experiment studied the effects of salt stress on the germination and seedling growth of endophyte-infected (E+) and endophyte-free (E-) S. purpurea seeds. The experiment treatments included different concentrations of single salt (NaCl, Na2SO4, Na2CO3 and NaHCO3) and compound salt (NaCl+Na2CO3) stress. It was found that the germination rate, germination power and germination index of S. purpurea seeds decreased progressively with successive increases in salt concentration, and the presence of Epichloё endophyte suppressed the downward trend for seed germinability. The intensity of seedling and radical growth inhibition increased with salt concentration and, the relative salt damage rate to seed germination also continued to increase. In addition, salt damage originating from Na2CO3 and Na2SO4 on seed germination and seedling growth of S. purpurea was higher than other salt types. Thus, Epichloё endophyte infection is one of the reasons why S. purpurea adapts to saline soil in Qinghai Lake Basin and becomes the dominant grass in alpine grassland. This information is relevant to ecological restoration of areas affected by soil salinization and identification of salt-tolerant grass germplasm and indicates the value of using the Epichloё endophyte symbiont with S. purpurea.

Key words: salt stress, salt type, Epichloё endophyte, Stipa purpurea, seed germination, seedling growth, relative salt damage rate