Molecular marker analysis for bacterial wilt resistance in mapping populations of tomato

An investigation on molecular markers for bacterial wilt resistance in mapping populations of tomato was undertaken to detect trait related markers linked to bacterial wilt resistance. Anagha was used as the resistant parent. DVRT-1 and Pusa Ruby were used as the susceptible parents. F₁ plants of both the crosses were found to be susceptible when grown in wilt sick field. F₂ population of both the crosses when transplanted into bacterial wilt sick plot, wilt incidence was observed to be 84.9 percentage in population of the cross Anagha x DVRT-1 and 67.7% in ^F2 the F₂ population of the cross Anagha x Pusa Ruby. Genomic DNA of parents, F₁ and F₂ population of both the crosses were characterized using 18 selected primers from OPF, OPAZ, OPS, OPAH, and OPY series. Though amplification was obtained with all the 18 primers, polymorphism was produced by only one primer OPS 16, in only one cross i.e. Anagha X DVRT-1. which gave a unique band of size ∼1.3 kb in Anagha, Anagha X DVRT-1 F₁, Anagha X DVRT-1 F₂ susceptible bulk and Anagha X DVRT-1 F₂ resistant bulk, but was absent in DVRT-1. When the whole F₂ population of thecrossAnagha x DVRT-1 wasanalyzed individuallywith the primer OPS 16, DNA of all the resistant plants showed 1.36 kb band. In the case of susceptible plants, a segregation of polymorphic band was observed. All this suggests that the gene for resistance to bacterial wilt in Anagha is recessive in nature and the polymorphic band produced by theprimer OPS16couldberelatedtobacterialwiltresistance.