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Effect of Root–Knot Nematode On Certain Some Physiological And

Biochemical Aspects of a Host Plant Solanum melongena

1
J. Shoba and D. Pechimuhtu 2
1 Assistant Professor and Associate Professor
2
Department of Zoology, V.O. Chidambaram College, Thoothukudi – 8, Tamilnadu.

*Email of corresponding author: shobavocc@gmail.com

ABSTRACT
Plant diseases caused by plant-parasitic nematodes substantially reduce economic crop

production every year, resulting in massive economic losses throughout the world. The root-
knot nematode Meloidogyne incognita is a widespread and polyphagous obligate asexual

endoparasite of plants that causes serious and growing problems to agriculture. This lifestyle
implies dramatic changes of plant cells into specialized feeding sites, which are induced by

secreted proteins by the nematode, so-called parasitism effectors. It alters the metabolic

process of the host which are manifested in the form of physiological and biochemical
changes occurring in the infected host. Eggplant (Solanum melongena) is one of the major

oil-seed crops. Their yields may be suppressed by many diseases including those caused by
plant-parasitic nematodes. This plant was selected for the present study. The carbohydrate

metabolism is altered in the host S. melongena were studied. The nematode infection led to
stunted growth and root galling. Due to nematode infection, the total sugar and starch

contents were found to be reduced in root and shoot system. Reductions of chlorophyll

content were also observed. Further enzyme activities were found to be decreased. Reduced
activities for β-amylase were noted. It was concluded that the carbohydrate metabolism of the

host plant was drastically affected by the root-knot infection.
Keyword: Meloidogyne incognita, Solanum melongena, Carbohydrate Metabolism,

Enzymes, Chlorophyll.

INTRODUCTION
In many economically important crops, the root-knot nematode, Meloidogyne

incognita causes considerable damage (Kofoid and white,1919; Chitwood,1949). These
economic effects on crop production have been well documented (Webster, 1972). In

addition to a decline in fruit production; heavily infected plants are stunted and exhibit

symptoms of nutritional deficiency. The most obvious morphological response to infection by
Meloidogyne spp is the characteristic of knotting or galling of the host plants roots for the

development and reproduction of Root-knot nematodes. These cells would provide a

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