Five medicinal plants, two agricultural crops grown in different agroclimatic conditions and one weed plant were tested for the presence of endophytic bacteria in their root and stem tissues. The plants tested were Cymbopogon citratus, Azadirachta indica, Phyllanthus emblica, Boerhaavia diffusa, Boerhaavia repens, Pisum sativum,Sorghum bicolorand Parthenium hysterophorus. Sixty different endophytic bacterial isolates belonging to different genera were isolated. Growth promotion ability of these endophytic bacteria was tested on seed germination, seedling vigor and biomass of pearl millet crop. The result indicated that, among sixty isolates tested, ten endophytic bacteria showed significant growth promoting effects on the pearl millet crop plants tested. The same endophytes when coated to seeds of pearl millet, the resulting seedlings showed resistance against downy mildew disease caused by Sclerospora graminicola, an oomycetes pathogen. Apron 35 SD and Benzothiadiazole (BTH) seed treatments were compared with endophytic bacterial treatments. Among the different endophytic bacteria, Pseudomonas fluorescens ISR 34 and Bacillus sp. ISR 37 showed highest protection of 68 and 63%, respectively. Experimental evidences have been provided to show that resistance offered in pearl millet against downy mildew disease is by induced systemic resistance phenomenon.
Chandrashekhara , Sathyanarayana Niranjanraj, Saligrama A. Deepak, Kestur N. Amruthesh, Nandini P. Shetty and Hunthrike S. Shetty, 2007. Endophytic Bacteria from Different Plant Origin Enhance Growth and Induce Downy Mildew Resistance in Pearl Millet. Asian Journal of Plant Pathology, 1: 1-11.