Analysis of biochemical parameters in tomato fruits before and after inoculation with root knot nematode (Meloydogyne incognita)

Abstract

Changes in biochemical and antioxidative parameters after nematode inoculation were investigated in tomatoes of four varieties, two resistant i.e. Hisar Lal, PNR-7 and two susceptible i.e. Punjab Varkha Bahar-1 and Punjab Varkha Bahar-2. These four varieties were infected at the nursery stage with root knot nematode (M. incognita). The egg masses of M. incognita were taken from the infected brinjal plants. The sampling of roots and leaves were done after 7 days and 20 days of infection. Tomato fruits from uninoculated and inoculated plants were evaluated for their nutritional quality parameters. The biochemical parameters such as lycopene carotenoids and ascorbic acid showed an increase in the inoculated tomato plants of resistant genotypes as compared to that of suseptible genotypes. TSS (total soluble solids) and titrable acidity showed a decrease in resistant genotypes after inoculation as compared to that of susceptible genotypes.There was no change in pH in both resistant as well as susceptible genotypes after inoculation. Roots and leaves of tomato varieties were taken at different time intervals after inoculation i.e. 7 days and 20 days after inoculation. The phenolic compounds showed an increase in the resistant varieties after inoculation with root knot nematode, whereas susceptible varieties showed a gradual decrease in phenolic compounds after inoculation. The orthodihydorxyphenols and flavonols also showed an increase after inoculation in resistant plants as compared to that in susceptible plants.