Could Alternaria solani IA300 be a plant growth-promoting fungus?

Abstract

In recent years the search for beneficial microorganisms that could induce plant growth has increased. Most have been found on crop seeds, soil and on the rhizosphere. In this work, we collected mature seeds of Phaseolus vulgaris var. Pinto Saltillo in Zacatecas, Mexico; and isolated endophytic fungi from these samples. Three different fungal strains were obtained. Sequencing analysis showed that one of the analyzed fungi, Alternaria solani IA300, showed the capacity to promote plant growth. Chili plants (Capsicum annuum cv. Mirasol) were inoculated with Alternaria solani IA300. After 15, 30, 45, and 60 days post-interaction, nine vegetative variables were analyzed (length of the root and aerial parts; weight of the root and aerial parts; number of leaves, flowers and fruits; as well as the dry weight from the root and aerial parts). Results showed that Alternaria solani IA300 can promote growth in chili pepper plants at later times of interaction (45 and 60 days post interaction), where most of the vegetative variables analyzed showed an increase in relation to control plants. To our knowledge, this is the first report where Alternaria solani IA300 induces growth and development in plants.