Influence of Downy Mildew Infection on the physiology of Pearl Millet Plants in an Arid Climate

摘要

Pearl millet, Pennhetum glauctm (L.) R.Br., is the principal cereal on 25 million ha of the drought-prone semi-arid regions of Africa and the Indian subcontinent, Downy mildew, caused by Sclerospom graminicola (Sacc.) I Schrot, is the most widespreadand destructive disease of pearl millet in the temperate and tropical areas of the world. It is especially important in India and western Africa. The pathogen colonizes the growing parts of the plant, through oospore and spoiangial infection and derangesthe physiological and biochemical processes. The first effect of the pathogen on host tissues appears to be an increase in the permeability of the plant cell, making nutrients available to the parasitizing fungus (Gour and Kumar 1992) and leading to destruction in turgor pressure. This, in turn, disturbs the water balance of the cell (Sadasivan 1968). This report briefly describes the alteration in water balance in the pearl millet plant following downy mildew infection in an arid climate.