Recent Progress on Rice Genetics in China

Abstract

Through thousands of years of evolution and cultivation, tremendously rich genetic diversity has been accumulated in rice (Oryza sativa L.), developing a large germplasm pool from which people can select varieties with morphologies of interest and other important agronomic traits. With the development of modern genetics, scientists have paid more attention to the genetic value of these elite varieties and germplasms, and such rich rice resources provide a good foundation for genetic research in China. Approximately 100 000 accessions of radiation-, chemical-or insertion-induced mutagenesis have been generated since the 1980s, and great progress has been made on rice molecular genetics. So far at least 16 variant/mutant genes including MOC1, BC1, SKC1, and Rf genes have been isolated and characterized in China. These achievements greatly promote the research on functional genomics, understanding the mechanism of plant development and molecular design breeding of rice in China. Here we review the progress of three aspects of rice genetics in China: moving forward at the molecular level, genetic research on elite varieties and germplasms, and new gene screening and genetic analysis using mutants. The prospects of rice genetics are also discussed. Available online at www.blackwell-synergy.com/links/toc/jipb, www.jipb.netAs the major force of evolution, variance exhibits plants' perfect adaptation to environments. Thousands of different traits and alleles emerge, because of genetic variance; they form a large germplasm pool from which people can select varieties with morphologies of interest and other important agronomic traits that best serve crop modification and plant breeding. Since Mendel's careful choice of traits led to the illustrious Mendel's Law, scientists not only pay attention to plant breeding through artificial selection and steering natural selection, but also show great interest in the genetic value of these variant morphologies.Rice (Oryza sativa L.) is one of the most important staple crops in the world and more than half of the world's population depends on it as a main source of nuturition ( Figure 1). Owing to its small genome size (~389 Mb), the known genome sequence (International Rice Genome Sequencing Project (IRGSP), 2005), ease of Agrobacterium-mediated transformation (Hiei et al. 1994), and genetic synteny with other cereal genomes (i.e. barley, wheat, maize and sorghum) (Bennetzen and Ma 2003), rice is not only a model monocotyledon for research on plant development, but also a model crop for research on cereals' genomics and evolution.Numerous scientists worldwide contributed great efforts to developments such as Mendelian segregation in rice (van der Stok 1908), an agreed system of rice chromosome numbering, and linkage groups and nomenclature for gene symbolization reported in succession (Kadam and Ramiah 1943; Nagao and Takahashi 1963) to make rice a favored higher plant for molecular and cellular genetic studies before 1980. With the development of molecular biology and mo...

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