北柴胡内生真菌分离鉴定及其生防促生活性分析

Isolation and Identification of Endophytic Fungi from Bupleurum chinensis DC.and Analysis of Their Biocontrol and Growth-Promoting Activity

为揭示北柴胡植株内生真菌组织分布特点,探索具有拮抗活性和促生活性内生真菌资源,本试验采用组织块分离法对北柴胡植株根、茎、叶内生真菌进行分离并鉴定,通过活性测试,包括体外抑菌活性、产真菌细胞壁降解酶能力、分泌IAA能力、固氮活性、解钾活性、溶磷活性、产铁载体能力,筛选具有生防与促生作用的北柴胡内生真菌。结果表明,北柴胡内生真菌在茎中的分离率(84.14%)、多样性指数(1.31)最高,青霉菌属(Penicillium)与生赤壳属(Bionectria)为根、叶内生真菌优势属,链格孢属(Alternaria)和曲霉属(Aspergillus)为茎内生真菌优势属。在54株测试菌株中,BCS-428[深绿木霉(Trichoderma atroviride)]及其发酵液抑菌活性最高,BCS-591[尖孢镰刀菌(Fusarium oxysporum)]及BCS-500[草酸青霉(Penicillium oxalicum)]具有较高的IAA分泌能力,分泌量分别为59.55 mg/L和76.16 mg/L。BCR-513[嗜松篮状菌(Talaromyces pinophilus)]具有较强的解钾活性,相比空白营养液,菌液可溶性钾增加26.76 mg/L;BCL-449(Coprinellus silvaticus)具有较强的固氮活性,菌液可溶性氮含量增加111.51 mg/L;BCR-427(Aphanocladium aranearum)和BCS-420[细疣篮状菌(Talaromyces verruculosus)]表现出较强的溶解有机磷与无机磷活性。综上,北柴胡内生真菌资源丰富,从北柴胡内生真菌中寻找开发生防与促生功能菌株具有巨大潜力。

In order to reveal the tissue distribution characteristics of endophytic fungi from Bupleurum chinense DC.and explore the resources of endophytic fungi with antagonistic and growth-promoting activities.In this study,the endophytic fungi from the roots,stems and leaves of B.chinense DC.were isolated and identi-fied by tissue block isolation method.The in vitro antibacterial activity,fungal cell wall degrading enzyme pro-duction ability,IAA secretion ability,nitrogen fixation activity,phosphorus-dissolving activity,phosphorus solubilization activity,and iron carrier production ability were tested to screen endophytic fungi from B.chinense DC.with biocontrol and growth-promoting effects.The results showed that the separation rate(84.14%)and diversity index(1.31)of endophytic fungi from the stems of B.chinense DC.were the highest.Penicillium and Bionectria were the dominant endophytic fungi genus in roots and leaves,while Alternaria and Aspergillus were the dominant ones in stem.Among the 54 tested strains,BCS-428(Trichoderma atroviride)and its fermentation broth had the highest antibacterial activity,BCS-591(Fusarium oxysporum)and BCS-500(Penicillium oxalicum)had higher IAA secretion ability with the secretion amounts of 59.55 mg/L and 76.16 mg/L,respectively.BCR-513(Talaromyces pinophilus)had stronger potassium-solubilizing activity,and com-pared to the blank nutrient solution,the soluble potassium in the bacterial solution increased by 26.76 mg/L.BCL-449(Coprinellus silvaticus)had stronger nitrogen fixation activity,and the soluble nitrogen content in bacterial liquid increased by 111.51 mg/L.BCR-427(Aphanocladium aranearum)and BCS-420(Talaromy-ces verruculosus)showed stronger activity in dissolving organic and inorganic phosphorus.In summary,the re-sources of endophytic fungi in B.chinense DC.were abundant,and there was great potential to search and de-velop biocontrol and growth-promoting strains from the endophytic fungi of B.chinense DC.