| 摘要: |
| 【目的】明确宁夏苦豆子不同器官可培养内生真菌的群落结构及其多样性，筛选能产喹诺里西啶生物碱的资源菌株，为苦豆子内生真菌资源开发利用提供理论依据。【方法】以宁夏回族自治区盐池县花马池镇天然草场的健康苦豆子为材料，采用组织分离法分别从苦豆子根、茎、叶和种子中分离可培养内生真菌，明确苦豆子可培养内生真菌的群落结构及其多样性。基于酸性染料比色法、薄层色谱法和高效液相色谱法，筛选产喹诺里西啶生物碱的内生真菌菌株，并利用多基因联合分析法明确其分类地位。【结果】采用组织分离法从苦豆子不同器官中分离得到可培养内生真菌394株，分离率为109.44%，定殖率为79.44%，隶属于18属，其中镰刀菌属（Fusarium）和链格孢属（Alternaria）为优势类群。苦豆子不同器官内生真菌群落组成与分布存在明显差异。根中优势属为镰刀菌属（Fusarium），相对分离频率为91.09%；茎中优势属为光黑壳属（Preussia），相对分离频率为74.03%；叶中优势属为座坚壳属（Rosellinia），相对分离频率为22.22%；种子中优势属为链格孢属（Alternaria），相对分离频率为59.26%。叶内生真菌群落多样性最高且分布最均匀，茎内生真菌群落丰富度最高，根中内生真菌群落多样性、丰富度和均匀度均最低。采用酸性染料比色法、薄层色谱法和高效液相色谱法从394株内生真菌中筛选出102株产喹诺里西啶生物碱的内生真菌菌株，占内生真菌总数的25.89%，产碱类型为槐定碱，产碱量为0.65~20.32 mg/g。其中镰刀菌属占产碱菌株的24.51%，包括尖孢镰刀菌（F.oxysporum）、变红镰刀菌（F.incarnatum）和茄病镰刀菌（F.solani）；链格孢属占产碱菌株的18.63%，均为互隔链格孢（A.alternata）。【结论】苦豆子中蕴藏着丰富的内生真菌资源，且内生真菌分布具有组织特异性。筛选产槐定碱内生真菌的种属多样，具有良好的开发潜力和应用前景。 |
| 关键词: 苦豆子 内生真菌 喹诺里西啶生物碱 槐定碱 |
| DOI：10.13207/j.jnwafu.2026.01.017 |
| 分类号: |
| 基金项目:宁夏回族自治区重点研发计划项目（2023BCF01026） |
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| Composition of culturable endophytic fungal communities in Sophora alopecuroides and screening of quinolizidine alkaloid-producing strains |
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JU Mingxiu, WANG Ruotong, LIU Guanlan, WANG Wenkai, JIN Jing, GU Peiwen
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School of Agriculture,Ningxia University,Yinchuan,Ningxia 750021,China
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| Abstract: |
| 【Objective】This study aimed to investigate the community structure and diversity of culturable endophytic fungi across distinct organs of Sophora alopecuroides in Ningxia,to screen fungal strains capable of producing quinolizidine alkaloids,and to thereby provide a theoretical basis for the development and utilization of its endophytic fungal resources.【Method】Healthy S.alopecuroides specimens collected from natural grasslands in Huamachi Town,Yanchi County,Ningxia Hui Autonomous Region were subjected to tissue isolation to obtain culturable endophytic fungi from roots,stems,leaves,and seeds,thereby characterizing the fungal community structure and diversity.Quinolizidine alkaloid-producing endophytic fungal strains were screened through approaches of acid dye colorimetry,thin-layer chromatography,and high-performance liquid chromatography.Taxonomic status of the highly active alkaloid-producing strains was subsequently determined via multi-locus phylogenetic analysis.【Result】A total of 394 culturable endophytic fungal strains were isolated from different organs of S.alopecuroide via tissue isolation,with a total isolation rate of 109.44% and a total colonization rate of 79.44%.These isolates belonged to 18 genera,with Fusarium and Alternaria being the dominant taxa.There were significant differences in the composition and distribution of endophytic fungal communities in different organs of S.alopecuroides.The dominant genus in the roots was Fusarium,with a relative isolation frequency of 91.09%.In the stems,Preussia was the dominant genus,with a relative isolation frequency of 74.03%.Rosellinia was the dominant genus in the leaves,accounting for a relative separation frequency of 22.22%. For the seeds,the dominant genus in the seeds was Alternaria,with a relative isolation frequency of 59.26%.Leaves displayed the highest diversity and evenness of distribution,while stems showed the greatest species richness.In contrast,roots showed the lowest values in diversity,richness,and evenness.A total of 102 strains of sophoridine producing endophytic fungi were identified from 394 fungal strains via acid dye colorimetry,thin-layer chromatography (TLC),and high-performance liquid chromatography (HPLC),accounting for 25.89% of the total endophytic fungi,with sophoridine yields ranging from 0.65 to 20.32 mg/g.Among the quinolizidine alkaloids-producing strains,Fusarium accounted for 24.51%,including F.oxysporum,F.incarnatum,and F.solani.While Alternaria accounted for 18.63% of the total,all of which were A.alternata.【Conclusion】There are abundant endophytic fungi resources in S.alopecuroides,and the distribution of endophytic fungi is tissue-specific.The taxonomic diversity of sophoridine-producing endophytic fungal strains screened in this study demonstrates substantial potential for future development and application. |
| Key words: Sophora alopecuroides endophytic fungi quinolizidine alkaloids sophoridine |
