Efeito de substratos sobre a germina？？o de uredosporos e comprimento de tubos germinativos de Puccinia triticina

the objective of this study was to test a methodology which provides a better germination rate of urediniospores and higher growth of germ tubes of the causal agent of wheat leaf rust (puccinia triticina) in relation to the water-agar substratum. the following substrata were tested: water-agar, potato-sucrose-agar (psa), 1/4 psa, dextrose-agar, fructose-agar, manitol-agar, sucrose-agar, wheat-leaves infusion-agar and, wheat-leaves extract-agar. a urediniospore suspension was poured on the substrata in petri dishes and incubated in growth room, in darkness at 20 oc, for 6, 12 and, 24 hours. germination of urediniospores and length of the germ tube were assessed. means for germination and germ tube length were compared by duncan test at 5%. the highest germination rate and germ tube growth were observed on the wheat-leaves infusion and wheat-leaves extract-agar substrata.