Potencial de Cepas Autóctonas de Bacillus Subtilis como Agente de Biocontrol de Alternaria Spp en Brassica Oleracea Var Italica Fase I

General objective To determine the capacity of autochthonous strains of Bacillus subtilis as a biocontrol agent for Alternaria spp. Justification Currently there is a growing demand from consumers for quality food, the concept of quality mainly involves the availability of products free of diseases and chemical residues harmful to human health, among the main foods that are consumed, fresh vegetables constitute a important pillar within the human diet (Bettiol, Rivera, Mondino, Montealegre, & Yelitza, 2012). For this reason, the production and management of crops through alternative strategies to reduce or replace the application of synthetic chemical products have acquired great importance, especially in crops that are exported whose markets are much more demanding. Alternaria sp is one of the main broccoli crop diseases characterized by blighting and damage to the inflorescence that begins as a brown discoloration that can involve one floret or several at the same time. It is dispersed with infected seeds, with cultivation tools or from plant to plant by wind or water. Often you can see on the underside of the leaves, dark spots like an oil stain; when this occurs, it is almost certain that the pellet, in any state of formation, will present one or several inflorescences with rot (Pavón, García, & Martín de Santos, 2008). The presence of the disease in the inflorescences of broccoli prevents them from being able to be marketed, it has been estimated that this disease can cause 30% loss of pellets (Cadena, 2011). The potential of Bacillus Subtilis is based on its ability to produce a wide range of bioactive molecules, which show strong antifungal properties, along with low toxicity, high biodegradability. Additionally, the ability to form endospores, which provide a high level of resistance to extreme environmental conditions (Villa, Alfonso, Rivero, & González, 2007). Currently, agriculture with more ecological practices is preferred, such as biological control, through the use of antagonistic microorganisms, which can limit the initiation and spread of diseases caused by plant pathogens through mechanisms of competition, antibiosis, resistance induction, among others. Through this research, it is intended to validate under controlled greenhouse and field tests the autochthonous Bacillus subtilis strains that demonstrated biocontrol activity of the phytopathogenic fungus Alternaria spp in the previous stage of the project, as well as an efficient conservation methodology.