Fusarium wilt caused by Fusarium oxysporum f. sp. lactucae (FOLAC) is one of the most important problems for lettuce growers because it causes major losses in production. To identify cultivars with potential for use in the management of the disease, 102 accessions were evaluated for resistance to isolates of race 1 of FOLAC. Initially, preliminary screening was done, using the isolate Fus-173. Then, 47 materials selected as highly resistant and a susceptible control (Regina) were reevaluated for resistance to other isolates of FOLAC race 1 from different locations: Fus-202 and Fus-205, in October 2011, Fus-219 and Fus-222, in November 2011; and Fus-207, Fus-209, and Fus-220 in December 2011. Inoculation was performed on 25 day old seedlings in the greenhouse by the method of cutting the roots and immersing them in the conidial suspension. The evaluation was performed using a scale ranging from 0 (healthy plant) to 4 (dead plant). Resulting data was transformed into a disease index and submitted to an analysis of variance and means comparison by the Tukey test (P=0.05). Thirty-two accessions were identified with wide resistance spectrum to different isolates of the pathogen in the four periods of inoculation.
Lactuca sativa; Fusarium wilt; genetic resistance
