Rice Germplasm, Genetics and Improvement

Rice is a cereal grain and represents the most consumed staple food for the major part of human population, especially in Asia. Rice is the seed of the grass specie Oryza sativa with two main subspecies (indica that is prevalent in tropical regions, and japonica, prevalent in the subtropical and temperate regions of Asia). In Africa, the most commonly cultivated species is Oryza glaberrima. Rice production has been improved during years, especially with genetic studies. In fact, to meet the growing necessity of food, more resistant and strong rice varieties with higher yield potential are needed. Moreover, geographic specific characterization and improvement for the different cultivars of rice represent a key point. In this book, latest papers about rice germplasm, genetic and improvement are compiled. The state-of-the-art of genomic studies on rice cultivars is reported. First, open-access resources for genome-wide association mapping in rice are proposed. Then, germplasm analyses of rice accessions from India, Europe, Bangladesh, and Japan are discussed, along with some specific properties. Detailed genetic studies about chloroplast genome sequencing, microRNA expression profile, SSP marker analysis and characterization of resistance-related genes are also presented. Finally, a new promising approach to overcome the inter-subspecific hybrid sterility is presented. Traditional rice varieties encompass a huge range of potentially valuable genes. These can be used to develop superior varieties for farmers to take part in the uphill battle of feeding an ever-increasing world population. The genes linked to valuable traits can help breeders create new rice varieties that have improved yield potential, higher nutritional quality, better ability to grow in problem soils, and improved tolerance of pests, diseases, and the stresses, such as flood and drought, that will be inevitable with future climate change. The high quality genome sequence of rice has provided a rich resource to mine information about diversity of genes and alleles which can contribute to improvement of useful agronomic traits.