ANALYSIS OF INTROGRESSIONS IN INTERSPECIF IC CROSSES OF RICE - UTILIZATION OF MOLECULAR MARKERS

Genetic diversity of wild rice species is of great interest to breedin g. Although there are strong reproductive barriers, interspecific hybr ids can be obtained through embryo rescue, and back-crossed to introdu ce useful characters into cultivated rice. As the rice RFLP (restricti on fragment length polymorphism) linkage map becomes more and more sat urated, mapped molecular markers provide a new and powerful tool to in vestigate and understand the -recombination process in distant crosses . Three different examples of application of molecular markers for int rogression monitoring are presented. They include work at ORSTOM (Inst itut francais de recherche scientifique pour le developpement en coope ration) Montpellier and collaborative research with IRRI (Internationa l Rice Research Insitute, Philippines) and Cornell University (USA). T his work involves the analysis of early generations or isogenic lines developed with wild rice species possessing the same genome as cultiva ted rice (O longistaminata) or cytogenetically different genomes (O br achyantha, F genome; O australiensis, E genome).