Department of Zoology, Visva-Bharati University, Santiniketan-731 235, West Bengal, India.
Changes in the total protein, carbohydrate and lipid in the roots of Hibiscus esculentus resulting from infection with root-knot nematodes were studied at 15, 30, 45 and 60 days after inoculation. The effect of a nematicidal plant extract of Anthocephalus cadamba, applied 1.0 days after inoculation, on the test plants during their growth was also studied. The galls appeared on root within 15 days after inoculation and increased in number very rapidly as the plants grew. The treated plants had always fewer galls. The population of root-knot nematodes inside the roots rose to a peak in 45 days and declined thereafter. The treated plants had fewer nematodes at all the observed growth stages. The total protein, carbohydrate and lipid in roots increased in amount with the growth of test plants, both inoculated and uninoculated. The inoculated plants had always higher amount of protein but lower amount of carbohydrate and lipid in roots than the uninoculated ones. The effect of treatment could be measured with root-protein only. The root-carbohydrate and root-lipid, which are thought to be reduced due to feeding by nematodes, provide additional biochemical parameters for evaluating the intensity of infection with root-knot nematodes.
