一株枸杞内生真菌的生防及促生作用的初步研究

Preliminary Studies on the Bioprophylactic and Growth-Promoting Effects of an Endophytic Fungus of Lycium barbarum

摘要: [目的]为筛选出对枸杞根腐病有生防作用的枸杞內生真菌，为枸杞根腐病防治提供理论依据。[方法]本研究通过组织分离法对3年生健康枸杞植株中的内生真菌进行分离；以枸杞根腐病主要致病菌——腐皮镰刀菌(Fusarium solani)和尖孢镰刀菌(Fusarium oxysporum)为供试菌，采用平板对峙法筛选致病菌的拮抗菌株，并通过形态学和分子生物学方法对拮抗菌株进行了种类鉴定。[结果]从枸杞植株中分离获得的64株内生真菌中，筛选得到对枸杞根腐病菌具有抑制效果的菌株L1-2，其中对腐皮镰刀菌的抑菌率为46.38%，对尖孢镰刀菌的抑菌率为45.13%。经鉴定菌株L1-2为苜蓿茎点霉(Phoma medicaginins)。苜蓿茎点霉发酵液处理后，枸杞组培苗叶片数、根长、茎长、最长叶长、干重和鲜重均有不同程度的增加，[结论]苜蓿茎点霉对腐皮镰刀菌，对尖孢镰刀菌有较好的拮抗作用，其发酵液也可以促进枸杞植株的生长。该研究结果可为有效利用微生物资源防治枸杞根腐病提供理论依据。

Abstract: Objective: To screen out the endophytic fungi of Lycium barbarum that have a bioprophylactic effect on root rot of Lycium barbarum, and to provide a theoretical basis for the control of root rot of Lycium barbarum. Methods: In this study, endophytic fungi were isolated from 3-year-old healthy Lycium barbarum plants by tissue isolation method; Fusarium solani and Fusarium oxysporum, the main causal organisms of Lycium barbarum root rot, were used as test organisms, and the antagonistic strains of the causal organisms were screened by the plate standoff method, and antagonistic strains were detected by morphological and molecular biological methods. The antagonist strains were identified by morphological and molecular biological methods. Results: Among the 64 endophytic fungi isolated from Lycium plants, strain L1-2 was found to have an inhibitory effect on Fusarium root rot of Lycium, with an inhibition rate of 46.38% against Fusarium verticillioides, and that of Fusarium acuminatum was 45.13%. The strain L1-2 was identified as Phoma medicaginins. The number of leaves, root length, stem length, longest leaf length, dry weight and fresh weight of Lycium barbarum seedlings increased to different degrees after treatment with the fermentation broth of Phoma medicaginins. Conclusion: Phoma medicaginins have a good antagonistic effect on Fusarium rotundum and Fusarium spinosum, and its fermentation broth can also promote the growth of Lycium barbarum plants. The results of this study can provide a theoretical basis for the effective use of microbial resources to prevent and control root rot of Lycium barbarum.