Biochemical response of Tomato genotypes to Meloidogyne incognita infection

A field trial was conducted in tomato with nine genotypes including two newly synthesized F₁ hybrids viz., CLN 2123 A X HN2 and HN2 X CLN 2123A and their parents CLN 2123A and HN2 along with resistant and susceptible check varieties/hybrids to study the biochemical response to root knot nematode infection at three different geographical locations viz., Rayakottai of Dharmapuri District, Oddanchatram of Dindigul District and Attur of Salem District of Tamil Nadu. The results revealed that the cross HN2 X CLN 2123A, nematode resistant check Hisar Lalit and the parent HN2 registered higher root phenol content and root ascorbic acid content, these genotypes also registered higher peroxidise activity, polyphenol oxidase activity, IAA oxidase activity and acid phosphatise activity. Similarly, the same genotypes also registered lower per se values for root-knot index in all the three locations of the study. Susceptible genotypes viz., (CO 3 & LCR 2) showed the lowest root phenol content, root ascorbic acid content, peroxidise activity, polyphenol oxidase activity, IAA oxidase activity, acid phosphatise activity and higher per se for root knot index in all the three locations of the study.