INTERIM REPORT ON TAXONOMY OF GRAMINICOLOUS DOWNY MILDEWS ATTACKING MAIZE

Abstract

The year 1976 is the centennial of graminicolous downy mildews (DM). Protomyces graminicola Sacc. [Sclerospora graminicola (Sacc. & Schroet.)] was described in 1876 on setaria verticillata (L.) Beauv. From Italy. It was not reported on maize (Zea mays L.) until 1909; in the interval, two other DMs were recorded on maize : Sclerospora maydis (Racib.) Butl. from Java in 1897 (as Peronospora maydis Racib.) and Sclerophthora macrospora (Sacc.) Thirum.et al. (as Sclerospora macrospore) from Italy in 1902. Since the last summary concerning the taxonomy of the graminicolus DMs on maize (12), several significant taxonomic developments have occurred. In articles published by Payak et al. (6) and Shaw (11) (both of which appeared in the DM issue of Indian Phytopathology), the former authors stated “Sclerophathora : sporangiophores determinate….” (p. 184), while the latter author stated “Sporangiophores indeterminate.. Sclerophathora”. Payak (personal communication) informed me that the basis for their statement was the cited abstract published by Thirumalachar (14).