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林业科学 ›› 2022, Vol. 58 ›› Issue (7): 63-72.doi: 10.11707/j.1001-7488.20220707

• 研究论文 • 上一篇    下一篇

干旱胁迫及外生菌根菌对马尾松幼苗根系形态及分泌物的影响

李敏,赵熙州,王好运,卢中科,丁贵杰*   

  1. 贵州省森林资源与环境研究中心/贵州省高原山地林木培育重点实验室 贵州大学林学院 贵阳 550025
  • 收稿日期:2021-06-27 出版日期:2022-07-25 发布日期:2022-11-03
  • 通讯作者: 丁贵杰
  • 基金资助:
    贵州省科技计划项目后补助计划项目(黔科合平台人才[2018]5261号);国家“十三五”重点研发计划项目(2017YFD0600302);贵州省科技计划项目重点实验室项目(黔科合平台人才[2019]5102号)

Effects of Drought Stress and Ectomycorrhizal Fungi on the Root Morphology and Exudates of Pinus massoniana Seedlings

Min Li,Xizhou Zhao,Haoyun Wang,Zhongke Lu,Guijie Ding*   

  1. Research Centre for Forest Resources & Environment of Guizhou Province/Key Laboratory of Forest Cultivation in Plateau mountain of Guizhou Province College of Forestry, Guizhou University Guiyang 550025
  • Received:2021-06-27 Online:2022-07-25 Published:2022-11-03
  • Contact: Guijie Ding

摘要:

目的: 探究干旱胁迫下接种不同外生菌根真菌对马尾松幼苗根系生长、形态、根系分泌物及根际土壤酶活性的影响,为阐明不同外生菌根菌促生抗逆的策略提供参考。方法: 采用棚内盆栽试验,分析正常浇水和干旱胁迫条件下,接种橙黄硬皮马勃(Sc)、琥珀乳牛肝菌(Sp)和未接菌(CK)马尾松幼苗的地上和地下生长、根系分泌物及根际土壤酶活性差异。结果: 1) 干旱胁迫抑制马尾松生长和根系活力,但接种Sc和Sp均能促进马尾松幼苗生长、生物量积累和根系活力,改善根系形态,以接种Sc效果更佳。2) 在根系分泌物中共检测出酸类、酮类、萜类、酯类、醇类和醛类6大类有机物质,共28种化合物。分泌物组成和相对含量受接菌和干旱胁迫调控,其中,接种Sc和Sp分别使分泌物种类增加和降低;无论是否接菌,分泌物种类均在干旱胁迫下增加;各类分泌物相对含量对干旱和接菌处理响应明显且存在差异,变化幅度和方向与分泌物种类有关;接种菌根菌能改变干旱胁迫下各类分泌物相对含量的变化,主要表现在抑制萜类相对含量、增加醛类相对含量,同时,酸类物质相对含量下降程度更大。菌根菌对同一组分不同化合物相对含量也有显著影响。3) 马尾松幼苗接种Sp后通过提高根际土壤脲酶和蔗糖酶促进植物生长,抵御干旱胁迫;接种Sc后通过维持较高的酸性磷酸酶和脲酶活性抵御干旱胁迫。结论: 马尾松幼苗接种Sp和Sc通过改善根系形态、提高根系活力和维持较高的土壤酶活性等方式促进生长和缓解干旱胁迫,以接种Sc缓解干旱胁迫的效果最佳。不同菌根菌接种处理后根系性状及其在干旱胁迫下的变化复杂且存在差异。

关键词: 马尾松, 外生菌根, 干旱, 根系分泌物, 土壤酶

Abstract:

Objective: To study the effects of different ectomycorrhizal fungi inoculation under drought stress on the root growth, root exudates and rhizosphere soil enzyme activities of Pinus massoniana seedlings, and to understand the strategies of different ectomycorrhizal fungi to promote growth and resist stress. Method: With the pot experiment in the greenhouse and two conditions of normal watering and drought stress, the difference in growth of above and below ground, root exudates and rhizosphere soil enzyme activities of different Pinus massoniana seedlings that respectively inoculated of Suillus placidus (Sp), Scleroderma citrinum (Sc) and uninoculated (CK) were studied. Result: 1) Drought stress inhibited growth and root vitality of P. massoniana seedlings, but Sc and Sp inoculation promoted seedling growth, biomass accumulation and root vitality, and also improved root morphology, with better performances in Sc inoculation seedlings. 2) A total of 6 types of organic substances, including acids, ketones, terpenoids, esters, alcohols and aldehydes, were detected in the root exudates, with a total of 28 compounds. The composition and relative content of secretions were regulated by inoculation and drought stress. Sc inoculation can increased the types of exudates while Sp inoculation decreased that; Drought stress increased the types of exudates and was not affected by inoculation; The relative content of various exudates responds obviously and differently to drought and inoculation treatments, and the change trends were related to the types of exudates. At the same time, the two ectomycorrhizal fungi also changed the relative content of various secretions under drought stress, mainly in inhibiting of the relative content of terpenoids, increasing of the relative content of aldehydes, and decreasing more in the relative content of acids. The effects of the two ectomycorrhizal fungi on the relative content of different compounds of the same component were also significantly different. 3) Sp inoculation treatment promoted plant growth and resists drought stress by increasing rhizosphere soil urease and invertase, while Sc treatment resisted drought stress by maintaining higher acid phosphatase and urease activities. Conclusion: Inoculation of Sp and Sc promoted the growth of P. massoniana and alleviate drought stress by improving root morphology, increasing root vitality and maintaining higher soil enzyme activities. Sc inoculation had the best effect on alleviating drought stress. Root traits and their changes under drought stress were complex and different after different mycorrhizal fungi inoculation. This is of great significance for understanding the mechanism of mycorrhizal fungi regulating root exudates in response to drought stress.

Key words: Pinus massoniana, ectomycorrhiza, drought, root exudates, soil enzyme

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