Pot Screening of Twenty Tomato Varieties (Solanum lycopersicum L.) in Response to Single and Interactive Effects of Fusarium oxysporum f.sp. lycopersici (Schlecht) Synder & Hansen and Root-knot Nematode (Meloidogyne javanica) Chitwood (Treub)

Abstract

Pot screening of twenty (20) tomato varieties was carried out with a view to determining wilting and root gall responses in terms of resistance or susceptibility to single and interactive effects of Fusarium oxysporum f.sp. lycopersici (Schlecht) Synder & Hansen and Root-knot Nematode (Meloidogyne javanica) Chitwood (Treub). The experiment was carried out in the screen house of the Department of Crop Protection, University of Abuja. Seeds of twenty varieties of tomato were sourced from the National Centre for Genetic Resources and Biotechnology (NACGRAB) and National Institute for Horticultural Research (NIHORT) in Ibadan. The test pathogens (F. oxysporum and M. javanica) were characterized conventionally and subsequently identified using molecular method through Polymerase Chain Reaction and gene sequencing techniques carried out carried out in the Bioscience/Molecular /Virology Laboratory of the International Institute of Tropical Agriculture (IITA), Ibadan, Oyo State, Nigeria.  The Completely Randomized Design (CRD) was used with 4 treatments and 5 replications per treatment. The disease symptomology of the interaction was documented. As a result, all the varieties recorded an average wilt severity of 15.00 ±1.58 and root gall of 37.20 ± 3.71. The red cherry tomato had the highest wilt severity (40.0%) caused by F. oxysporum while Tropimech (75.6) and Alausa (75.5) had the highest number of root galls caused by M. javanica. Simultaneous inoculation of F. oxysporum and M. javanica in pot screening experiment resulted in high Fusarium wilting and root gall formation in Beske 11 Jm4, Beske 1 Jm3 and Red cherry. However, Onitrye variety showed tendency for resistance to both pathogens.  On the basis of their responses and performances, four varieties were selecte: Onityre, Zumoured, Roma savanna and Riogrande. These varieties should be subjected to further pot and field evaluations to determine the effects of the pathogens on their agronomic characteristics including growth and yield parameters, and make an informed decision to growers and breeders.