Diversidad de bacterias endófitas asociadas a plantas de jitomate (Solanum lycopersicum)

Spanish; Castilian. Resumen. En este estudio se propuso como objetivo identificar las bacterias endófitas aisladas de plantas de jitomate y caracterizarlas en función de propiedades promotoras del crecimiento vegetal. Se realizaron recolectas de plantas de jitomate asintomáticas de la variedad Missouri. Los tejidos (raíz, tallo y hojas) fueron esterilizados superficialmente, se maceraron y se establecieron en agar nutritivo. Adicionalmente, se sembraron semillas in vitro (THB y SUN6366) y del tejido se realizó el mismo procedimiento. Con los aislados bacterianos obtenidos, se analizaron algunas actividades promotoras de crecimiento vegetal (producción de sideróforos, quitinasa y solubilización de fosfato). Las bacterias obtenidas se identificaron morfológicamente y secuenciaron. Se obtuvieron 25 aislados: 10 in vitro (50 plantas) y 15 de campo (20 plantas). Siete aislados axénicos (uno in vitro y seis de campo) se identificaron molecularmente como Methylobacterium radiotolerans, Shinella sp., Burkholderia cepacia, Sphingobium herbicidovorans, Pseudomonas sp., Achromobacter xylosoxidans y Rhizobium radiobacter. Methylobacterium aislado in vitro, sin reportes en plantas de jitomate. Aproximadamente el 86% de los aislados mostraron al menos una actividad benéfica, relacionada con el crecimiento y salud de las plantas. Pseudomonas, Burkholderia y Rhizobium presentaron alta capacidad fosfatosolubilizadora. Estos resultados permiten suponer que las bacterias endófitas en jitomate muestran potencial para ser utilizadas como bioinoculantes en otros cultivos de importancia agrícola.

English. Abstract. In this study, the objective was to identify the endophytic bacteria isolated from tomato plants and characterize them based on properties that promote plant growth. Collections of asymptomatic tomato plants of the Missouri variety were carried out. The tissues (root, stem and leaves) were superficially sterilized, macerated and seeded in nutrient agar. Additionally, seeds were sown in vitro (THB and SUN6366) and the same procedure was performed on the tissue. With the obtained bacterial isolates, some plant growth promoting activities were analyzed (production of siderophores, chitinase and phosphate solubilization). The bacteria obtained were morphologically identified and sequenced. 25 isolates were obtained: 10 in vitro (50 plants) and 15 field (20 plants). Seven axenic isolates (one in vitro and six field isolates) were molecularly identified as Methylobacterium radiotolerans, Shinella sp., Burkholderia cepacia, Sphingobium herbicidovorans, Pseudomonas sp., Achromobacter xylosoxidans and Rhizobium radiobacter. Methylobacterium isolated in vitro, without reports in tomato plants. Approximately 86% of the isolates showed at least one beneficial activity, related to plant growth and health. Pseudomonas, Burkholderia and Rhizobium presented high phosphate-solubilizing capacity. These results allow us to suppose that the endophytic bacteria in tomato show potential to be used as bioinoculants in other crops of agricultural importance.