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Source of inoculums

Matured egg masses of M. incognita were isolated from the plant, Acalypha indica L
as primary inoculums. The egg masses were surface sterilized with 0.01%sodium

hypochlorite solution and transferred to brass gauze filters overlaid with mull cloth. The
gauze assembly was lowered in a small plastic vial (1’’x1”) and kept in contact with a small

quantity of water at the bottom for hatching. Freshly hatched juveniles were collected and
used for inoculation.

Inoculation of the pathogen
Each seedling was inoculated with 2000 second stage larvae by pipetting more or less

evenly into four holes dug among the seedling in the soil of the pots to facilitate infection
from all sides around the roots. The holes were then covered with a thin film of sterilized

sand and watered very lightly. All the plants such as control-uninfected and infected-treated

plants were watered with the nutrient solution once a week till the harvesting period (30days).

BIOCHEMICAL STUDIES
Sample preparation for biochemical estimation :(Allam et al.,1980)

Thirty days after inoculation, the plants were depotted and washed with tap water to
remove sand particles rinsed again with distilled water and blotted with filter paper. For

evaluation, the plants were separated into root and shoot and weighed as quickly as possible

to reduce water loss. The roots and shoots were then separated and dried in a hot air oven for
a week to obtain a constant weight. These dried samples were ground to60 mesh powder

separately. These dried powders were stored and used for biochemical studies. The total
sugar content of various samples was estimated by employing the procedure of Seifter et al.

(1950), Estimation of starch by Jayaraman, 1981 and β-Amylase activity (Bernsfeld, 1995)

Chlorophyll contents were estimated by employing Arnon (1949) method.

Estimation of enzymes
The use of Triphenyl Tetrazolium Chloride (TTC) as an artificial electron acceptor

had been introduced by Kun and Abood (1949). In the present studies, TTCwas employed to
determine the activities of the various enzymes investigated. The intensity of the reduced red

coloured formazon (indicating the liberation of hydrogen from the substrate and the

absorption of by colourless TTC which was reduced to red coloured formazon). Indicative of
the enzyme activity was matched with the artificially reduced formation standard as follows.

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