Plant Growth Promoting Activity Of Trichoderma Spp. And Its Potential Biocontrol Against Colletotrichum Gloesporioides

Abstract

Anthracnose caused by Colletotrichum gloesporioides is one of the main diseases that has limited the production of Dioscorea spp. yam in the Caribbean region. To control the pathogen requires the application of agrochemicals, but this has caused environmental problems. Trichoderma spp. has properties in promoting plant growth and controlling phytopathogens, being proposed as an alternative to replace chemical fertilizers. Currently little is known about the defense mechanisms that Trichoderma spp. species can confer when applied to crops of agricultural interest for protection against pathogens. In turn, in the department of Sucre the diversity of Trichoderma spp. has not been exhaustively explored and how these can be used to increase the yield and development of crops in the region. To evaluate the antagonistic activity of Trichoderma spp. against C. gloesporioides and its potential plant growth promoter in vitro. Samples were taken from yam cultivation in the municipalities of Ovejas and Chalán. Serial diluteons were performed for the isolation of Trichoderma spp. Once the strains were purified, the antagonism test against C. gloesporioides was performed in PDA culture medium. For the promotion of growth, the SRS medium for phosphate solubilization and the CAS medium for the production of siderophores were used. DNA extraction and identification of the isolates was performed using the tef1 gene.  The species Trichoderma harzianum, T. atroviride and T. asperellum showed inhibition against the pathogen (p<0.05) and promoted plant growth. These species release enzymes that can degrade the cell wall of the pathogen causing it to die or inhibit its growth by producing secondary metabolites. The application of Trichoderma spp. in crops confers protection against pathogens and stimulates plant growth in order to obtain a good yield.