Screening of cucumber varieties resistant to Cucumber green mottle mosaic virus

Abstract

To screen and characterize sources of Cucumber green mottle mosaic virus (CGMMV) resistantvarieties of cucumber, the 139 cucumber varieties obtained from several commercial and germplasm collectionswere evaluated by mechanical inoculation in a greenhouse. The standard CGMMV screening method developed bySiriyan et al.(2006) was used. The crude sap of infected CGMMV cucumber leaves was rubbed on carborundumdusted colyledons of 7 day old cucumber seedlings (10 plants/variety). The seedlings were kept in the insect provedgreenhouse for symptom observation. Type of disease symptom was evaluated at 14 and 30 days after inoculationand confirmed the presence of CGMMV by ELISA. The disease rating of each testing plant was further converted topercentage of disease index (% DI) which will be used for determination the CGMMV resistant phenotype. Resultshowed that 32 of cucumber varieties were resistant (R), 80 varieties were moderately resistant (MR), 15 varietieswere moderately susceptible (MS), 8 varieties were susceptible (S), and 4 varieties were highly susceptible (HS).