Patogenicidad y agresividad de seis aislados de Fusarium circinatum a Pinus spp.

Abstract

This study aimed to evaluate the pathogenicity and aggressiveness of six isolates from Fusarium circinatum to Pinus spp. The process began with the reactivation of the six fungal isolates cultured in PDA (potato dextrose agar) medium for ten days in dark conditions, after which the inoculum was prepared. To the mycelium cultivated in PDA medium, 10 mL of distilled water was added to each of the Petri dishes, then a suspension of spores was obtained. Finally, the spore count was performed, allowing the adjustment of its concentration. The inoculation of the plants was carried out using two methods: method one consisted of injecting 1mL of inoculum, and the suspension was applied at the level of the stem in the lower part using sterile syringes. Method 2 consisted of placing 5mL of inoculum directly into the tube. The plants inoculated by the strains of Fusarium circinatum., presented external symptoms of yellowing, discoloration of the foliage, bending of the growth bud, more than 50% of the dead foliage, and wilting of the plant, followed by death. The Pinus plants inoculated with the six isolates of Fusarium circinatum by the two methods were pathogenic, causing external symptoms in the plant. Treatment 4 (FC1P) showed the highest incidence, severity, and most aggressive, presenting the symptoms in a shorter incubation period than the other treatments and where the method (1) firstly showed the symptoms of the disease. This is due to the much faster interaction of the pathogen with the plant tissue to be colonized. It is recommended to carry out studies in other Pinus producing areas to determine the pathogenicity, aggressiveness, and evaluation of antagonists for biological and chemical control in Pinus spp.