A promising breeding strategy for tomato resistance to Cucumber Mosaic Virus based on genetic analysis

Indonesian Vegetables Research Institute, Jl Tangkuban Perahu 517, Lembang, Indonesia 40391

^* Corresponding author: redwanto_1@yahoo.co.id

Abstract

Infection of CMV can reduce tomato yield. One of the controlling methods to solve the problem by using a resistant variety. However, the existence of resistant variety was still not available yet. Therefore, we needed the breeding program for resistance tomato to CMV to obtain a new variety. Information of previous genetic analysis results can be used to determine a promising strategy. Two tomato genotypes namely R8 51-12 as resistant and RG-57 as susceptible accession were crossed reciprocally to obtain F₁, F_1R, BC_1.1, BC_1.2, F₂. Then, all of the breeding materials were inoculated by strain CMV-2 and observed on symptom disease and virus concentration. Genetic analysis results showed that there was no maternal effect and the resistance controlled by two major genes as recessive, but there was the epistatic effect on disease symptom as a selection parameter. Based on these information, the tomato’s breeding strategy were to use a susceptible genotype as female parent, while a resistant genotype as male parent. Phenotypically disease symptom selection can be conducted in the middle or late generation. However, the selection should be supported by serologically using the Elisa test. The breeding program could be addressed as a F₁ hybrid variety.