Appraisal for multiple disease resistance in advanced breeding lines of tomato (Solanum lycopersicum L.)

The leaf curl disease (ToLCD), late blight (LB) and root knot nematode (RKN) are the major obstacles for rainy season tomato production all over the world. Several tactics are being considered for the management of these diseases. Reportedly, the most efficient way to manage these multiple diseases is to adopt resistant cultivars. Though, work on development of resistant cultivars against multiple diseases are very confined due to non-availability of the resistant sources. In the present study, BC2F6 population comprising 132 elite tomato lines were evaluated using different screening techniques including marker assisted selection (MAS) during 2019-2020 and 2020-2021. Punjab Chuhhara (check) was used as susceptible for all three diseases, while PVB-4, LBR-10 and NR-14 were the resistant checks for ToLCD, LB and RKN, respectively. The lines which showed resistance and moderately resistance responses under field and artificial conditions were exposed for MAS of major resistant genes (Ty-1, Ty-2, Ty-3, Ph-2, Ph-3 and Mi-1.2). PDRT-104, PDRT-118, PDRT-122, PDRT-124 and PDRT-125 were found to provide multiple disease resistant. There was significant correlation between the phenotypic and genotypic based screening. The resistant lines identified in the present evaluation can be utilized to develop cultivars for potential durable resistance to multiple diseases.