Diversity of endophytic fungal and bacterial communities in Ilex paraguariensis grown under field conditions

PEREZ, MARÍA LAURA; COLLAVINO, MÓNICA M.; SANSBERRO, PEDRO A.; MROGINSKI, LUIS A; GALDEANO, ERNESTINA

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2016 vol. 32 p. 61 - 76

0959-3993

The composition and diversity of the endophyticcommunity associated with yerba mate (Ilexparaguariensis) was investigated using culture-dependingmethods. Fungi were identified based on their micromorphologicalcharacteristics and internal transcribed spacerrDNA sequence analysis; for bacteria 16S rDNA sequenceanalysis was used. Fungal and bacterial diversity did notshow significant differences between organ age. Thehighest fungal diversity was registered during fall seasonand the lowest in winter. Bacterial diversity was higher instems and increased from summer to winter, in contrastwith leaves, which decreased. The most frequently isolatedfungus was Fusarium, followed by Colletotrichum; theywere both present in all the sampling seasons and organtypes assayed. Actinobacteria represented 57.5 % of allbacterial isolates. The most dominant bacterial taxa wereCurtobacterium and Microbacterium. Other bacteria frequentlyfound were Methylobacterium, Sphingomonas,Herbiconiux and Bacillus. Nitrogen fixation and phosphatesolubilization activity, ACC deaminase production andantagonism against plant fungal pathogens were assayed inendophytic bacterial strains. In the case of fungi, strains ofTrichoderma, Penicillium and Aspergillus were assayed forantagonism against pathogenic Fusarium sp. All microbialisolates assayed showed at least one growth promoting activity. Strains of Bacillus, Pantoea, Curtobacterium,Methylobacterium, Brevundimonas and Paenibacillus hadat least two growth-promoting activities, and Bacillus,Paenibacillus and the three endophytic fungi showed highantagonistic activity against Fusarium sp. In this work wehave made a wide study of the culturable endophyticcommunity within yerba mate plants and found that severalmicrobial isolates could be considered as potential inoculantsuseful for improving yerba mate production.