Genetics and molecular markers for resistance to major soil borne pathogens in chilli (Capsicum annuum L.)

Abstract

Three major soil borne pathogens namely Phytophthora capsaici Leon causing root rot, bacterium Ralastonia solanacearum causing bacterial wilt and root- knot nematodes (Meloidogyne spp.) are pervasive across the major pepper growing parts of world mainly in the areas of repeated cultivation and poly houses impeding production as these pathogens are very difficult/ impossible to control. Repeated application of chemicals is in practice among the farmers and chemical management often leads to environmental pollution and the presence of pesticide residues in the fruits thus raises the concern of food safety and reduces the export potential. Recently grafting strategy using resistant root stock has been proposed mainly for protected cultivation. Resistance breeding through incorporating the resistant genes/QTLs is the best advocated strategy to circumvent these devastating soil-borne diseases which aim at developing a variety/root stock having combined and durable resistance. Marker assisted backcross breeding is the best method which ensures precise transfer of the resistant genes/QTLs of interest from the donors to the recurrent parent with accelerated recurrent parent genome which requires thorough knowledge on the molecular marker available for fore ground selection. This review mainly emphasized on the molecular markers available for breeding peppers for combined resistance to soil borne pathogens