Transmission

Dry seed examination of 103 samples of chilli (Capsicum sp.) collected from 16 districts of Rajasthan revealed asymptomatic (06.25-94.25%), moderately discoloured (01.75-42%) and shrivelled-discoloured (01.25-27.75%) seeds in 103, 101 and 100 seed samples, respectively. The discolorations varied from cream to purple-brown spots, water-soaked translucent areas which yielded colonies of Xanthomonas axonopodis pv. vesicatoria on incubation. The standard cultural, biochemical and pathogenecity tests were carried out for identification of the bacterium. The isolates were gram's negative, KOH solubility test positive, levan negative, lipase activity positive, Kovac’s oxidase negative or weak, nitrates were not denitrified or reduced but catalase positive, starch hydrolyzing, gelatin liquefying, hypersensitivity on tobacco leaves after infiltration. Out of 103seed samples, 85 (82.52%) seed samples of 16 districts of Rajasthan revealed 10-100% incidence of the pathogen on Tween-80 medium. The seed-borne inoculum caused pre- and post- emergence losses and symptoms of browning of radicle, splitting of plumule; necrotic spots with bacterial oozing and bright in cotyledonary leaves.