In this study the susceptibility of different genotypes of gladiolus (Gladiolus callianthus and the genotypes of G. grandiflorum T-704, Red Beauty, Tradehorn, Verônica, Amsterdam, Yester Gold, and Rose Friendship) was evaluated and correlated with the development of Curvularia gladioli infective structures. The plants were inoculated with a 3 x 10(4) conidial suspension of the pathogen, and the severity of infection was assessed eight days after inoculation. Leaf samples of G. callianthus and G. grandiflorum vars. Amsterdam, Red Beauty, and T-704 were collected 24 hours after inoculation. They were cleared and the rates of spore germination and appressorium formation of C. gladioli were quantified. G. grandiflorum vars. T-704 and Red Beauty were the most susceptible genotypes, followed by G. callianthus and G. grandiflorum var. Tradehorn. The remaining genotypes did not differentiate among them. No differences related to the conidial germination (93.5%) were found for the genotypes. However, the highest values for appressorium formation were observed for G. callianthus (66.5%) and G. grandiflorus var. Amsterdam (55.7%), and the lowest values were observed for T-704 (32.4%). Thus, appressorium formation of C. gladioli was higher on leaf surfaces of resistant genotypes.
Gladiolus callianthus; Gladiolus grandiflorum; appressorium; curvularia leaf spot; flower bulb
