Breeding Plants for Future Climates

Abstract

At present, the erratic environmental conditions along with ever-increasing human population have created a problem for the agricultural researchers to fulfill the world food demand, with present rate of increase in crop production. Increase in world mean temperature along with shortage of freshwater has further worsened this situation. Due to increasing greenhouse effect in last few decades, it has increased the average world temperature more than 1.5 oC that increased the evapotranspiration and created a problem of aridity in some areas of the world. It is estimated that till 2050, there is a need to double the world food production with a rate of 2–5% per year but present rate of only 0.9%. It is only possible by increasing the crop production area or by crop production per capita. The former one is not possible in present environmental conditions due to limited sources of freshwater. However, it is possible to achieve the latter one through different ways, when there is a limited supply of water. It is possible through the selection from the available germplasm that can perform better with better production under the changing environmental conditions, and it seems the important and foremost way to deal with the problems of world food demand. Crop breeding for the selection of varieties with better production under changing and stressful environmental conditions is gaining interest. In this regard, the selection of crop varieties against different abiotic stresses for better production seems to be the most important one. Normally, the breeding for the selection of stress-tolerant crop varieties is based on different agronomic traits (traits of interest) such as plant biomass production, yield attributes, and different stress tolerance indices that are considered necessary ones. The stress tolerance mechanism in plants is a phenomenon of different cellular physio-biochemical attributes. However, it is a complex mechanism because the stress tolerance in crops is multigenic and complex mechanism and is purely under the control of genetics. In this regard, present interest and focus of researchers in the study of quantitative trait loci (QTLs) has played an important role for the selection and development of stress-tolerant crop varieties in a short time. Though the fruitful success regarding the QTL-based selection has been achieved, but due to the complexity in multigenic nature of stress tolerance, the behavior of the crop varieties changes under the changing environmental conditions. The present chapter is a comprehensive update regarding selection of stress-tolerant crop varieties for better production under the changing environmental conditions. So, in the future in view of changing environmental scenario, it is necessary to find out or develop the crop varieties that can perform better with better production under such conditions that will be fruitful to fulfill the world food demand for ever-increasing world population at present and in the near future.