Conventional Plant Breeding Program for Disease Resistance

Abstract

Disease resistance is of great concern for plant breeding programs. Diseases are a major yield-limiting factor, caused by many air born, soil born or waterborne microorganisms, which in fact are a risk for food security. Improving efficacy of management practices can increase yields, but only to a limited extent, whereas plant breeding as a technology increases yields to large extents. Advancements in new science and technology allow the development of tools whereas old ones are also refined. Most cost-effective and environment-friendly methods applied in disease resistance programs include adoption of conventional breeding approaches. There are two type of resistance, namely vertical (controlled by major genes) and horizontal (controlled by minor genes). Breeding programs change with respect to crops, diseases and pathogens. In spite of this, main objective is the accumulation of favorable gene(s) into cultivars, to deal with a given scenario. Selection, introduction, hybridization and screening are the main steps of a successful breeding program. Landraces, related species, mutations and wild relatives are the sources of resistance. They can be utilized for resistance introduction in commercial cultivars. Selection of resistant cultivar is the most robust and cheap method, allowing thereby introduction of resistant cultivar into a new region. Moreover, resistant cultivars are used to cross with local cultivars for introduction of resistance genes into them. The rapid evolution of phytopathogens and crops susceptibility pose severe issues, therefore disease resistance represents a complex aspect of any program. Being also affected by the environment it still represents a big challenge for breeders.