Screening for Tolerance-Resistance to Root-knot nematode Meloidogyne incognita in Grafted and Ungrafted Cucurbit Rootstocks

Abstract

T HE CURRENT study aimed to screen eight ungrafted and grafted cucurbit rootstocks as well as melon Hybrid London genotype against root-knot nematode infection. Ungrafted and grafted rootstocks i.e. Nun 6001, Squash No3, Super Shintosa, Flixel Fort, Ferro RZ, Coplt, Bottle gourd were classified as tolerant to M. incognita infection whereas melon genotype Hybrid London and Pakistani Loof rootstock ranked as susceptible hosts. Grafted cucurbit rootstocks i.e. Nun 6001 and Ferro RZ, gave the higher plant survival rate and growth parameters compared to ungrafted ones and the rest of rootstocks and melon genotype. Number of galls, females, and egg masses of M. incongita were significantly suppressed in ungrafted and grafted rootstocks compared to melon plant Hybrid London. All the rootstocks differed in their ability to stimulate peroxidase (PO), polyphenol oxidase (PPO) activities, and phenol content. The study revealed that grafting melon plants onto all the previous tolerant rootstocks is an effective tool that may enable the susceptible melon scion to tolerate M. incognita which leads to an increase in plant survival rate and growth parameters.