辣椒叶际固氮菌分离筛选及抑菌活性

Isolation and Screening of Nitrogen-Fixing Bacteria from Leaves of Pepper and Antifungal Activity

为后续研制叶面微生物菌肥提供优良固氮菌种,以辣椒为研究对象,利用选择性培养基分离、筛选辣椒叶际固氮细菌,测定其固氮能力和植物病原菌的拮抗能力并对性能优良的菌株进行16S rDNA分子生物学鉴定。研究表明,从辣椒叶际共分离得到2株具有高效固氮性能的自生固氮菌LJ-1和LJ-2,分别鉴定为不动杆菌(Acinetobacter sp.)和根瘤菌(Rhizobium sp.),固氮酶活性分别达93.26和102.23 U·L^(-1)。两株菌具有广谱抗真菌活性和耐酸碱能力,对油菜菌核病菌、番茄灰霉病菌和棉花立枯病菌抑制效果可达50%以上。因此,辣椒叶际固氮菌LJ-1和LJ-2是具有固氮和生防作用的多功能细菌,可为进一步研发优良的叶际固氮菌肥提供微生物资源。

In order to provide excellent nitrogen-fixing bacteria strains for the subsequent development of biofertilizer,the leaves of pepper were taken as the research object and the selective incubation culture medium was used to separate and screen phyllosphere nitrogen-fixing bacteria,and determine their ability to N fixation,antagonistic ability against plant pathogenic.The species of strains were identified based on morphological characteristics and the phylogenetic analysis of partial 16S rDNA sequence.The results showed that two nitrogen-fixing strains of LJ-1(Acinetobacter sp.)and LJ-2(Rhizobium sp.)were isolated from the leaves of pepper and the nitrogenase activity was 93.26 and 102.23 U·L^(-1),respectively.The two strains had broad-spectrum antifungal activity and acid-alkali resistance,and the inhibitory effects against Sclerotinia sclerotiorum,Botrytis cinerea,Rhizoctonia solani were more than 50%.The phyllosphere nitrogen-fixing strains LJ-1 and LJ-2 had nitrogen fixation and biocontrol functions,which could provide microbial resources for development of phyllosphere nitrogen-fixing bacteria fertilizer.