Disease Resistance in Rice and Wheat for Better Adaptation to Climate Change

The world population is predicted to reach more than nine billion by 2050, requiring an increase of about 50% in food production relative to current levels. It is a major challenge to ensure sustainable food production without further expanding area of cultivated crops. Plant breeding is important for improving yield and tolerance to existing and emerging biotic and abiotic stresses.  Cereals are the key staple crops for food security of world population, supplying around 42,5% of the global food calorie supply. Rice and wheat make up almost half of the cereals consumed, the predictions for 2017/18 being 703 and 503 million tonnes respectively (FAO, 2017 - http://www.fao.org/3/a-i8278e.pdf). Rice is grown all over the world and is the main staple for about 50% of the world population (IRRI, 2015; AfricaRice, 2015). The world today still has huge concentrations of poverty and most of these concentrations are where rice is grown. While wheat production is mostly confined to temperate climates, wheat is the staple food for hundreds of millions of poor people in developing countries. Wheat provides around one-fifth of all calories and protein for people globally. In developing countries, wheat feeds around 1.2 billion people who live on less than US$ 2 a day.  Diseases are among the major obstacles hindering yield improvements both in rice and wheat. Changing climatic conditions help spread of the diseases to new destinations and exacerbate their impact. In addition to the already widely spread diseases of rice such as blast, sheath blight, false and bacterial leaf blight, threats of emerging diseases are becoming more serious such as in the case of false smut of rice and blast of wheat. Thus, to minimize the impact of these diseases environmentally friendly and cost-effective technologies are needed for prevention and management of these diseases. Development and utilization of disease resistant varieties is the most effective, affordable and environmentally friendly approach for management of these threats. Use of mutation breeding technique appears as a viable tool in development of such germplasms and varieties. Breeding for disease resistance aims to incorporate durable resistance into improved rice and wheat varieties. However, varieties released as resistant became susceptible after years/decades of cultivation due to pathogen evolution and adaptation to cultivated varieties. Thus, breeding for disease resistance is a continuous challenge to rice/wheat breeders and pathologists. Rice diseases (bacterial, fungal, or viral) threaten food productivity. For example, one of the largest impediments to increased rice production is the presence of rice blast (Magnaporthe oryzae, fungus), which directly decreases rice yields and indirectly increases production costs. Rice blast is one of the most frequent and costly rice diseases in temperate rice-growing regions worldwide. Host resistance is the most efficient, environmentally friendly method to cope with such diverse pathogens. Wheat blast was identified initially in Brazil in 1985. It gradually expanded in South America to around 3 million ha in early 1990s. The disease appeared in Bangladesh in 2016 and became rapidly a serious threat to wheat production in the country. There is the fear that the disease might spread further in the country and also to the neighbouring countries putting the wheat production in the region at a great risk. This CRP proposes the use of physical mutagenesis and associated screening technologies to broaden the genetic base of resistance in rice and wheat. The project seeks to link rice and wheat improvement programs in the Member States and IAEA staff. This would combine expertise in field, screen house and laboratory screening to enhance mutation breeding to timely develop or adapt screening packages to generate novel sources of disease resistance in rice and wheat.  Up to ten research contracts are expected to be awarded and up to five no-cost agreement holders from advanced laboratories. Research institutes with recognized expertise in the targeted technologies will be invited to share their experience with the contract holders and contribute to the development and validation of the planned technical packages. In addition, it is foreseen that two technical contracts will be awarded for services in advanced areas such as marker development and mutant characterization. Coordination and technical management will be handled by the scientific secretary in the Plant Breeding and Genetics Section with involvement of Plant Breeding and Genetics Laboratory.