ABSTRACT
Phytobacteriology or plant bacteriology is a sub discipline of plant pathology, which deals with plant-associated bacteria and their interactions with each other and with their hosts. A brief account of procaryotes and their two domains, namely, the bacteria and the archaea, is given. The salient features of Gram-stain-negative bacteria and Gram-stain-positive bacteria having cell walls, and bacteria lacing cell walls, which distinguish these groups from each other, are given. The distinguishing features of phytopathogenic bacteria and their economic importance are given.
The economic importance and estimates of yield losses caused by important plant diseases, namely, bacterial wilt of solanaceous plants, citrus huanglongbing, citrus canker, Pierce’s disease of grapevine, bacterial blight of rice, and fire blight of apple and pears are highlighted. A brief mention of harmful effects of phytopathogenic bacteria to mankind, in addition to causing direct loss in crop yield and quality, is made. The commercial value of phytopathogenic bacteria in industrial fermentation, production of vinegar, curdlans, pectin-degrading enzymes, and restriction enzymes is highlighted. The role of avirulence genes in determining the race specificity of pathogens in a compatible host pathogen interaction is given. A historical review of phytobacteriology, highlighting the milestones, is given. A brief account of development of phytobacteriology in India is also given.
