Marker aided selection for disease resistance in vegetable crops

The development of improved varieties/hybrids resistant to the pathogens has been one of the remarkable achievements of conventional plant breeding. The steps and essential requirements for the marker aided selection (MAS) and the applications of MAS in disease resistance breeding in vegetable crops have been highlighted. Among the available genetic markers, viz., morphological, cytological, biochemical and molecular (DNA), the DNA markers are increasingly being utilized in MAS for disease resistance due to its several inherent advantages. The cost effectiveness, high reproducibility, ability to screen large sample size and detect maximum polymorphism has been the major considerations in developing new DNA techniques. Efforts are under progress towards the automation of steps involved in developing DNA markers like DNA extraction, DNA quantification, assembly of amplification reaction, allele analysis and data readout. The available reports on success of molecular markers based MAS suggest that marker technique or combination of techniques for MAS should be selected case by case.