CARACTERIZAÇÃO BIOLÓGICA DE UM BACTERIÓFAGO EM ISOLADO DO FILOPLANO DE Solanum americanum COM POTENCIAL PARA O BIOCONTROLE DA MANCHA BACTERIANA DO TOMATEIRO

Abstract

The present study aimed to bioprospect, characterize, and evaluate the potential of a bacteriophage isolated from Solanum americanum leaves for the biocontrol of bacterial spot in tomato. The bacteriophage Xanthomonas phage SA1 was isolated from samples collected in the tomato trial at the Morrinhos campus of IF Goiano, using spot test and plaque assay techniques, followed by successive purification cycles to obtain a clonal isolate. Phage stability was evaluated in vitro under different pH, temperature, and UV radiation conditions, showing viability at pH 5 and 7.4, progressive reduction in viability with increased exposure to UV (254 nm), and greater preservation of lytic activity at 25 °C and 30 °C, with complete loss at 65 °C. The host range revealed selective activity against Xanthomonas euvisicatoria pv. perforans. isolates, X. hortorum pv. gardneri and X. campestri pv. campestris Greenhouse trials demonstrated a significant reduction in disease severity following phage application, and additional observations indicated improved survival of phage-treated plants under severe heat stress, suggesting possible induction of basal resistance. These results indicate that phage SA1 has promising potential as a biocontrol agent against Xanthomonas in tomato, offering a sustainable alternative for disease management and plant protection under adverse conditions.