Morphological identification of pathogenic agents associated with Tabebuia rosea (Bignoniaceae) in nursery stage in morelia (Risaralda)

Abstract

Introduction. The susceptibilities of plantations to attack by harmful organisms can cause harmful effects for their development, when it is considered that the level of damage caused cannot be tolerated, it is essential to correctly determine the nature of the causal agent, be it biotic or abiotic; The correct determination of the agent of a phytosanitary problem in a nursery or forest plantations is based on a detailed analysis of the factors that may be affecting it. Tabebuia rosea or pink Guayacán is a native forest species widely accepted in the market, which presents, during its nursery stage, limitations in the germination, emergence and survival phases, therefore the objective of this research was to morphologically identify the possible pathogens associated with Tabebuia rosea in the nursery stage and check its pathogenicity. Methodology. Nursery seedlings were taken, which were analyzed for signs and symptoms for the isolation and sowing of affected areas on potato dextrose agar. In the mixed culture, possible pathogens were identified, which were sown to obtain pure cultures, and used in the pathogenicity test, for the inoculation of healthy structures (leaves, petioles and stems) and their respective control. Results. Three fungal genera Colletotrichum, Mucor, and Candida, and a nematode genus named Meloidogyne were identified. The pathogenicity test for Colletotrichum and Candida showed significant relationships in the infection process mainly in leaf structures. Two new possible pathogenic genera for Tabebuia rosea evidenced in the pathogenicity test are concluded in this work. And it is corroborated that the genus Meloidogyne is a severe pathogen in the pink guayacán that causes morphological anomalies in the root; It should be noted that it is the first report for the department of Risaralda