植物生态学报 ›› 2010, Vol. 34 ›› Issue (12): 1433-1438.DOI: 10.3773/j.issn.1005-264x.2010.12.009

• 研究论文 • 上一篇    下一篇

实验室条件下五唇兰菌根真菌专一性研究

侯天文1, 金辉2, 刘红霞1,*(), 罗毅波2   

  1. 1北京林业大学, 森林培育与保护教育部重点实验室, 北京 100083
    2中国科学院植物研究所, 系统与进化植物学国家重点实验室, 北京 100093
  • 收稿日期:2010-05-20 接受日期:2010-08-31 出版日期:2010-05-20 发布日期:2010-12-28
  • 通讯作者: 刘红霞
  • 作者简介:(E-mail: hongxia@bjfu.edu.cn)

Mycorrhizal specificity of Doritis pulcherrima in in-vitro research

HOU Tian-Wen1, JIN Hui2, LIU Hong-Xia1,*(), LUO Yi-Bo2   

  1. 1The Key Laboratory for Silviculture and Conservation of Conservation of Ministry of Education, Beijing Forestry University, Beijing 100083, China
    2State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2010-05-20 Accepted:2010-08-31 Online:2010-05-20 Published:2010-12-28
  • Contact: LIU Hong-Xia

摘要:

利用从高原温带兰科植物菌根中获得的22个菌根真菌菌株, 对五唇兰(Doritis pulcherrima)进行了室内种子萌发、原球茎分化和组培苗回接试验, 从交叉回接的角度对附生兰科植物与菌根真菌的生理专一性进行了探讨。经过20周的共生培养, 只有编号为Cf1和Mm1的两个菌株使种子表现出种胚明显膨大的萌发迹象; 9个菌株能够促使原球茎较好地分化发育出根叶; 11个菌株处理苗的平均鲜重增长率高于对照组(156.25%), 其中Mm1的效果达到极显著水平(p = 0.01)。通过根切片显微观察, 在原球茎分化根和回接效果良好的处理苗的根皮层组织发现典型的菌丝团结构, 表明菌根体系已成功建立。温带地生兰菌根真菌对五唇兰种子萌发、原球茎发育和幼苗生长等3个重要生长阶段影响的试验显示, 五唇兰的种子和菌根真菌的共生萌发效果不佳, 而原球茎及幼株更容易与之建立良好的共生关系。同时, 也没有发现同一个真菌菌株能够对五唇兰的种子、原球茎和幼苗均产生促进作用。研究结果表明, 五唇兰的菌根真菌专一性因生理生长阶段的不同而存在差异。

关键词: 附生兰, 菌根真菌, 专一性, 室内种子萌发, 共生培养, 生存策略

Abstract:

Aims The degree of specificity of mycorrhizal association in tropical orchids has been controversial for many years. Our objective is to address this issue.
Methods Twenty-two endophyte fungal strains isolated from the roots of wild temperate terrestrial orchids were inoculated with the seeds, protocorms and seedlings of tropical epiphytic orchid species Doritis pulcherrima in flasks. Transverse sections of roots were observed by microscope.
Important findings After 20-weeks cultivation, only the fungal strains Cf1 and Mm1 caused swelling of the embryo, and nine caused differentiation of the protocorms into leaves or roots. The other fungal strains were pathogenic or had no function in seed germination and protocorm differentiation. In the seedling-fungi symbiotic treatment, the survival rate of the seedlings reached 100% and 11 of 22 fungal strains significantly enhanced the seedling growth. The fungal strain Mm1 had the most significant effect on increasing fresh mass of seedling. The existence of pelotons in the cortex of the roots of the protocorms and seedlings indicated successful infection. The effects of 22 endophyte fungal strains on seed germination, protocorm development and seedling growth of D. pulcherrima showed that the endophyte fungi did not enhance seed germination but were associated with the protocorms and seedlings; However, no one fungus was associated with all three key stages simultaneously. Our study suggested that the degree of specificity of tropical epiphyte orchids is influenced by the development stages of the plant.

Key words: epiphytic orchid, mycorrhizal, specificity, symbiotic germination in vitro, symbiotic cultivation, survival strategy