Identification of Tm Genes for Tomato mosaic virus (ToMV) Resistance in Tomato Germplasm

摘要

Use of resistant germplasm is an effective, successful and eco-friendly approach to manage Tomato mosaic virus (ToMV) in tomato. Identity of ToMV in tomato was confirmed through reverse - transcriptase polymerase chain reaction (RT-PCR), an amplicon size of 300bp was obtained for coat protein gene of ToMV. Totally, 35 entries of tomato were screened for the identification of resistance source through mechanical inoculation under glasshouse condition. As per the severity scale, six were found resistant, 11 moderately resistant, 12 moderately susceptible, six were susceptible and none were immune to ToMV infection. The presence of Tm genes in the resistant once were identified using sequence characterized amplified region (SCAR) and allele specific (AS1) markers for Tm-1 and Tm-2 genes respectively. Both Tm-1 and Tm-2 genes were identified in hybrid Arka Rakshak and in lines such as LA0887, TLB 503-3-2 and CK 12. However, Tm-2 alone was present in TLB-409 and TLB-504-1-1, similarly Tm-1 was detectedin var. Sankranti which exhibited moderately resistant response. In case of susceptible hybrid Indus 1030, no amplification of Tm genes were noticed indicating Tm-1 and Tm-2 genes have shown to be responsible for resistance to ToMV infection in tomato germplasm.