Diversity of cultivable endophytic bacteria associated with blueberry plants (Vaccinium corymbosum L.) cv. Biloxi with plant growth-promoting traits
Magdalena A. Ortiz-Galeana1, Julie E. Hernández-Salmerón1, Brenda Valenzuela-Aragón2, Sergio de los Santos-Villalobos3, Ma. del Carmen Rocha-Granados4 y Gustavo Santoyo1*
The present work explores the diversity of cultivable endophytic bacteria associated with blueberry plants (Vaccinium corymbosum L.) cv. Biloxi, and characterizes their plant growth promoting activities, including the production of indoleacetic acid (AIA), biofilm, siderophores and proteolytic activity. Bacterial endophytes were isolated from different tissues of blueberry plants. A higher population density of endophytic bacteria was obtained from roots compared stems and leaves. BLAST and hylogenetic analysis, based on 16S ribosomal gene sequencing, showed the identification of 24 bacterial species distributed in 4 Phyla, such as Bacteroidetes (1.1%), Actinobacteria (23.9%), Firmicutes (12.5%) and Proteobacteria (62.5%). The most abundant genera were Pantoea, Pseudomonas, Burkholderia and Bacillus, among others. When analyzing some plant growth-promoting activities, 42% of the ndophyte isolates showed at least one beneficial activity. Interestingly, some strains of Bacillus and Pantoea showed better production of phytohormones (AIA), biofilm and siderophores compared to the well-known PGPR Pseudomonas fluorescens UM270. These results show that the bacterial endophytes could play a beneficial role in blueberry plants, and be potentially used as bioinoculants in other crops of agricultural importance.
Key words: bacterial endophytes, plant growth-promoting bacteria, genetic diversity, Vaccinium, blueberry.
1 Laboratorio de Diversidad Genómica, Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacán, México.
2 Laboratorio de Biotecnología del Recurso Microbiano, Instituto Tecnológico de Sonora Ciudad Obregón, Sonora, México.
3 CONACYT-Instituto Tecnológico de Sonora, Ciudad Obregón, Sonora, México.
4 Facultad de Agrobiología ¨Presidente Juárez¨, Universidad Michoacana de San Nicolás de Hidalgo, Uruapan, Michoacán, México.
* Autor para correspondencia E-mail: [email protected]