Vanessa Beatriz Monteiro Galassi Spini

Mancha de Septoria da alface: isolamento, inoculação e avaliação de cultivares em condições de campo e casa de vegetação

ABSTRACT Lettuce Septoria leaf spot: isolation, inoculation, cultivarevaluation in field and greenhouse conditions The objectives of this work were to establish appropriatemethodologies for isolation and inoculation of Septoria lactucae inorder to evaluate resistance. Nine lettuce ( Lactuca sativa ) cultivars(Vitoria-de-Santo-Antao, Uberlândia 10.000, Maioba, Elba, Aurelia,Black Seeded Simpson, Grand, Rapids, Salad Bowl-Mimosa andBaba de Verao) were screened for resistance to this pathogen undergreenhouse and field conditions. The best results obtained were: a)for isolation: to transfer cirrus of conidia directly to the surface ofPetri dishes with PDA medium plus antibiotics (streptomycin,chloramphenicol, ampicilim and riphampicin); b) for inoculation:to spray plants of six to eight leaves with a conidia suspension of1 x 10 4 spores/ml and keep them in a moist chamber for 48 h.Significant differences were found among cultivars both ingreenhouse and field tests. Under both conditions the cultivarsMaioba and Vitoria de Santo Antao were found to be, respectively,the most susceptible and the most resistant cultivars among thosetested. From these results, the greenhouse test methodology isseen to ge highly promising for the rapid screening of a greatnumber of genotypes in breeding programs of lettuce resistant to