Screening of cucurbitaceous rootstocks and cucumber scions for root knot nematode resistance (Meloidogyne incognita Kofoid and White)

A study was carried out under glasshouse condition at the Department of Nematology, Tamil Nadu Agricultural University, Coimbatore during 2012-2013 to identify resistant rootstocks of cucurbitaceous species for grafting of cucumber against root knot nematode, Meloidogyne incognita . Seven wild and cultivated cucurbitaceous rootstocks and two cucumber scions (variety and hybrid) were used for screening studies against the root knot nematode. Forty fifth day after inoculation, the plants were evaluated for shoot length, root length, shoot fresh and dry weight as well as root fresh and dry weight, number of galls per 10 gram of root, egg mass and females per gram of root, root knot index, soil nematode population per 200 cc of soil and reproduction factor. The lowest number of galls and egg masses were observed in Citrullus colocynthis followed by Cucumis metuliferus which exhibited resistant reaction with root knot index (RKI) of 2. The other rootstocks viz ., Cucurbita ficifolia, Cucurbita moschata, C. maxima and Luffa cylindrica were found to be moderately resistant to root knot nematode with root knot index of 3. The two cucumber scions (Green Long variety and NS 408 hybrid) were observed to be highly susceptible to M. incognita with RKI of 5.