Sclerospora graminicola Axenic Culture

Abstract

Sclerospora graminicola (Sacc.) Schroet., the obligate pathlogen causing downy mildew (green-ear) of pearl millet (Pennisetum typhoides Stapf. and Hubb.) has been successfully cultured for the first time on a known semisynthetic mediumn with no evident loss of fructifications. Sclerospora graminicola was first grown on host callus tissue and subsequently on a modification of White's basal medium that contained casein hydrolyzate (Oxoid). 2,4-dichlorophenoxyacetic acid, and kinetin.

Bridging the Gulf: Phytophthora and Downy Mildews Are Connected by Rare Grass Parasites

“…The report of cultivation by Tiwari & Arya [40] was supported by a photograph showing sporangiophores from which new sporangiophores were repeatedly arising. However, the successful cultivation of neither Sclerophthora nor Sclerospora has been reported again and so it is possible that the observations made by Tiwari & Arya [40] and Tokura [31] were fortuitous and not readily repeatable. Nevertheless, these results support the obvious assumption that obligate biotrophy has gradually evolved in the basal downy mildews until complete dependence on living host cells was established.…”

“…Recent phylogenetic reconstructions clearly place Sclerospora amongst the downy mildews [14], [15] and not with the Saprolegniomycetidae as proposed by Dick [7]. The report of cultivation by Tiwari & Arya [40] was supported by a photograph showing sporangiophores from which new sporangiophores were repeatedly arising. However, the successful cultivation of neither Sclerophthora nor Sclerospora has been reported again and so it is possible that the observations made by Tiwari & Arya [40] and Tokura [31] were fortuitous and not readily repeatable.…”

“…The second downy mildew genus which has been reported to be culturable on artificial media is Sclerospora [40], which has always been accepted as a distinct genus. Recent phylogenetic reconstructions clearly place Sclerospora amongst the downy mildews [14], [15] and not with the Saprolegniomycetidae as proposed by Dick [7].…”

Growth of Albugo candida (race unidentified) on Brassica juncea callus cultures

“…candida and B. juncea. There is, however, a report by Tiwari and Arya (1969) which suggests the importance of AA and CH in the growth of dual cultures of Pennisetum o,phoides and an obligate parasite Sclerospora graminicola -a pathogen phylogenetically related to Albugo.…”

“…Sacristan and Hoffman (1979) devised a technique for direct infection of cultured Brassica napus tissues with resting spores of P brassicae; the fungus developed and completed its life cycle in cultured cells. Tiwari and Arya (1969) reported saprophytic growth of Sclerospora graminicola on artificial medium. Cutter (1960) obtained dual growth, but limited sporulation, of the rust fungus Urono'ces aritriphylli on callus tissues of its host Arisaema triphyllum.…”