Abstract

PASSADOR, Martha Maria; BARRETO FIGUEIREDO, Mário  and  FURTADO, Edson Luiz. Inhibiting effect of the aqueous extract from telioid teliospores of the fungus Puccinia pampeana Speg., on causal agents of rusts. Rev. mex. fitopatol [online]. 2008, vol.26, n.2, pp.138-146. ISSN 2007-8080.

Green pepper rust is caused by the fungus Puccinia pampeana. Since this fungus has two distinct telial forms, it is classified as a biteliomorphic rust. The first form occurs at the beginning of symptom appearance, with aecidioid, golden-yellow, catenulate teliospores surrounded by a peridium. The second one occurs at the end of the fungus cycle in the host, with dark brown, pulvinate, bicellular, pedicellate telioid teliospores, which contain germination self-inhibiting substances in their walls, that can be removed by washing. Aqueous extracts were prepared with 20 mg of Puccinia pampeana telioid teliospores, and tested on germination inhibition of aecidioid teliospores of the same rust and of urediniospores of Coleosporium plumierae and Hemileia vastratrix. The inhibiting effect was demonstrated by measuring metabasidial length (aecidioid teliospores of P. pampeana) and germ tube length of C. plumierae and H. vastratrix. The inhibiting effect was verified after 4 and 6 h of contact of spores with the extracts.

Keywords : Self-inhibitor; germination; metabasidium; germinative tube.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )