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草业学报 ›› 2025, Vol. 34 ›› Issue (1): 135-150.DOI: 10.11686/cyxb2024122

• 研究论文 • 上一篇    

内生真菌对根寄生逆境下紫花针茅根系形态的影响

李媛1,2,3(), 孟思宇1(), 冯晓云1,2,3, 鲍根生1,2,3()   

  1. 1.青海大学畜牧兽医科学院,青海 西宁 810003
    2.青海省畜牧兽医科学院,青海 西宁 810016
    3.青海省青藏高原优质牧草种质资源利用重点实验室,青海 西宁 810016
  • 收稿日期:2024-04-10 修回日期:2024-06-05 出版日期:2025-01-20 发布日期:2024-11-04
  • 通讯作者: 鲍根生
  • 作者简介:E-mail: baogensheng2008@hotmail.com
    李媛(1999-),女,甘肃平凉人,在读硕士。E-mail: liy19991226@163.com
    孟思宇(1997-),女,辽宁铁岭人,在读博士。E-mail: 2012370280@qq.com第一联系人:共同第一作者
  • 基金资助:
    国家自然科学基金项目(32060398)

Effect of the Epichloë endophyte on the root morphology of Stipa purpurea infected by the hemiparasite Pedicularis kansuensis

Yuan LI1,2,3(), Si-yu MENG1(), Xiao-yun FENG1,2,3, Gen-sheng BAO1,2,3()   

  1. 1.Academy of Animal Science and Veterinary Medicine,Qinghai University,Xining 810003,China
    2.Qinghai Academy of Animal Science and Veterinary Medicine,Xining 810016,China
    3.Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau,Xining 810016,China
  • Received:2024-04-10 Revised:2024-06-05 Online:2025-01-20 Published:2024-11-04
  • Contact: Gen-sheng BAO
  • About author:First author contact:These authors contributed equally to this work.

摘要:

甘肃马先蒿是一种根寄生杂草,利用吸器在紫花针茅根部建立营养摄取通道,并掠夺性获取紫花针茅体内营养物质,从而抑制紫花针茅生长。研究表明,Epichlo?内生真菌与紫花针茅共生能缓解甘肃马先蒿寄生对紫花针茅的生长抑制作用,这可能与内生真菌调控紫花针茅根系形态特征有关。本研究以带菌(E+)、不带菌(E-)紫花针茅为研究对象开展盆栽试验,探究甘肃马先蒿寄生密度对紫花针茅根系形态的影响。结果表明:1)甘肃马先蒿寄生显著降低了紫花针茅地上和根系生物量,抑制了紫花针茅根系的生长发育,且随寄生密度增加,紫花针茅生物量和根系形态指数持续降低,但E+植株的生物量和根系形态优于E-植株。2)通过结构方程模型分析发现,甘肃马先蒿寄生能抑制紫花针茅根长、根表面积和根系拓扑指数,导致紫花针茅生物量降低,且随寄生密度的增大,甘肃马先蒿对紫花针茅生长的抑制作用不断增强。内生真菌通过改变紫花针茅根长、根表面积和外部连接数等根系形态特征对甘肃马先蒿寄生作出正向的积极响应,进而增加紫花针茅生物量。由此可见,内生真菌能通过调控根系形态特征来增强紫花针茅根系和地上生物量,进而缓解甘肃马先蒿对紫花针茅的根寄生危害,这将为利用禾草内生真菌共生体这一特殊资源对根寄生杂草防控提供新思路。

关键词: 香柱菌属内生真菌, 紫花针茅, 甘肃马先蒿, 根寄生植物, 根系形态

Abstract:

The root hemiparasite Pedicularis kansuensis derives nutrients from its host, Stipa purpurea, through structures known as haustoria, and this suppresses the growth of S. purpurea. Previous studies have shown that Epichlo? endophytes, microorganisms that form a symbiotic relationship with their host, are able to ameliorate the damage to S. purpurea caused by the hemiparasite P. kansuensis. The potential mechanism of this effect may be that Epichlo? positively regulates the root morphology of its host infected with the hemiparasite. In this study, we conducted a pot experiment to compare the root morphology between endophyte-infected (E+) and endophyte-free (E-) S. purpurea parasitized by P. kansuensis at different densities. Our results indicate that parasitism by P. kansuensis decreased both the shoot and root biomass of S. purpurea, and resulted in substantially decreased values of all the measured root morphological traits. The values of biomass and root morphological traits of S. purpurea sharply decreased with increasing density of P. kansuensis. The values of biomass and root morphological parameters of S. purpurea parasitized by P. kansuensis were higher in the E+ group than in the E- group. A structural equation model indicated that as the total length, surface area, and topological index of S. purpurea roots decreased, the biomass of S. purpurea decreased. The inhibitory effect of P. kansuensis on the growth of S. purpurea was positively related to the density of P. kansuensis. By contrast, the presence of the Epichlo? endophyte facilitated the accumulation of biomass of S. purpurea parasitized by P. kansuensis through altered root morphological traits including root total length and surface area, and the number of externally connected grass roots. In conclusion, Epichlo? endophytes are able to alleviate stress imposed by a hemiparasite upon P. kansuensis by facilitating change in its root morphological traits. Our findings reveal new information about the mutualistic relationship between Epichlo? endophytes and their hosts, and demonstrate that the introduction of the Epichlo? symbiont isan effective biological method to control hemiparasitic weeds.

Key words: Epichlo? endophyte, Stipa purpurea, Pedicularis kansuensis, root hemiparasite plant, root morphology