Powdery Mildew Perspective

Abstract

Powdery mildews were first recognized as white powdery appearance on the leaves of Humulus, Acer, Lamia, Galeopsis, and Lithospermum by plant pathogens infection as early as 1753 which was named as Mucor erysiphe. Initially powdery mildews were a fascinating subject of research for mycologists who reported several species of powdery mildews on different hosts on the basis of minor differences in their morphological characteristics. The economic importance of powdery mildews was realized in 1850 with the most wide spread, and disastrous losses attributable to powdery mildew of grapes in France. Later, during nineteenth century, powdery mildew diseases of barley, gooseberry, peaches, cucurbits, and several other crops have been found to cause economic losses in many countries of the world. The crucifer’s powdery mildew has gained its importance as an economically damaging disease during last two decades of twentieth century. In total, upto now, more than 873 species of powdery mildews have been reported to cause infection to nearly 10,000 plant species all over the world. The powdery mildew of crucifers (Arabidopsis) is considered as one of the “Top ten fungal pathogens for molecular, and genetical studies all over the world”. The classification, taxonomy, nomenclature, and identification of powdery mildew fungal genera, and species has now been resolved with the use of morphological data of both anamorph, and teleomorph stages, host range, using light, and scanning electron microscopy, and phylogenetical analysis. In future, under the new rules, powdery mildew fungi will be treated for nomenclaturaly like plants, and all other groups of organisms ruled by the “International code of nomenclature for algae, fungi and plants” i.e., with one correct name for each species. Recently, powdery mildews have shown their potential as biological weed control agent. Some hyperparasites of powdery mildews have been identified with practical application under field conditions for powdery mildew disease control. With global warming, powdery mildews may become threatening, and more devastating disease all over the world. The information revealed on genetical, and molecular mechanisms of host-parasite interaction will be helpful in planning strategies of powdery mildew management under field conditions.