Breeding for Abiotic Stress Tolerance in Crop Plants

Abstract

Human exploitation of earth’s resources is leading to new problems day by day and hence newer methods are devised to overcome the same. The long-term goal of crop improvement for abiotic stress tolerance in plants is a traditional objective of breeders. World population is expected to increase by 1.8 billion as of 2030 and by 2.5 billion as of 2050, reaching 9.2 billion. By 2030 food demand is expected to increase by 50 percent because of continued population growth and higher incomes (www.popcouncil. org). If global population reaches 9.1 billion by 2050, the FAO says that world food production will need to rise by 70 per cent, and food production in the developing world will need to double. On the other hand food productivity is decreasing due to the effect of various abiotic stresses; therefore minimizing these losses is a major area of concern for all nations to cope with the increasing food requirements. However, abiotic stresses and climate change are becoming increasingly serious threats to crop production worldwide at a time when food staple supply will need to be significantly higher to meet the demand of the growing human population. Drought is the main abiotic factor followed by soil salinity. Now-a-days, agriculture has new huge challenges due to population growth, the pressure on agriculture liability on the environmental conservation, and climate change. To cope with these new challenges, many plant breeding programs have reoriented their breeding scope to stress tolerance in the last years. One such case is breeding for abiotic stress, utilizing even non arable land, to feed the ever increasing population. Research is the key to meeting the challenges of modern agriculture in a sustainable and positive fashion. So, in this chapter, emphasis has been given on importance of abiotic stresses specially on drought and salinity, sources of abiotic stress tolerance, genetics of abiotic stress tolerance, plant breeding presents the conventional (selection and introduction, pedigree method, modified bulk pedigree method, shuttle breeding, mutation breeding, diallele selective mating system supplemented by MAS, back cross method and recurrent selection), and most recent advances and discoveries (somaclonal approach, F1 anther culture, marker assisted selection and genetically modified crop) applied to abiotic stresses, discussing the breeding methods, and modern molecular biological approaches to develop improved cultivars tolerant to most sorts of abiotic stresses. In this chapter more discussed about successful example of conventional breeding methods and non conventional methods because the breeding procedure of each breeding methods is not possible in one chapter.