Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/5/2008
Publication Date: 3/1/2008
Citation: Sanchez, P.L., Kudrna, D., Eizenga, G.C., Wing, R.A. 2008. The Oryza Map Alignment Project (OMAP) introgression lines for allelic diversity and new germplasm development. In: Proceedings of the 32nd Rice Technical Working Group Meetings, February 18-21, 2008, San Diego, CA. 2008. CDROM.
Technical Abstract: The Oryza Map Alignment Project (OMAP) has developed a genus wide model system for the study of rice that will ultimately provide a complete understanding of the genus. The purpose of this project is to capitalize on the strengths of the Arizona Genomics Institute (AGI), OMAP participants and the rice breeding community to continuously provide, for years to come, useful and previously unexplored germplasm materials to increase rice genetic diversity and initiate new cultivar development. At this point in the project, immediately the AA genome species can be crossed to cultivated rice for creating new diverse genotypes. We will use three approaches: (1) advanced backcross (ABC) populations for allele identification, (2) chromosome substitution lines (CSSL) for analytical introgression of wild germplasm segments using marker assisted selection (MAS) and (3) construction of the first molecular genetic maps of more distant Oryza species for long term mining of useful genes and alleles from rice relatives. The ABC and CSSL populations, MAS and QTL mapping will be used for identifying environmentally useful traits (i.e., cold and aluminum tolerance, stress, drought, etc), disease and insect resistance, milling quality and yield traits. For particular interest, we selected elite rice cultivars M202, LaGrue and Nipponbare as introgression recipient lines. M202 and LaGrue are grown largely in California and Southern regions in the US; both are in line for alignment resequencing to the IRGSP pseudomolecules that will strengthen their utility and usefulness. Nipponbare was the first cultivated rice genome completely sequenced and has vast molecular resources for downstream research that may involve structural and functional genomics as well as proteomics. The AA genome wild rice accessions are of interest for identification of potential useful alleles and genes as well as for advanced scientific study. Of interest: O. meridionalis (IRGC104092), O. glumaepatula (IRGC100969) because of their geographical origin (Australia and Suriname) which is different from O. rufipogon accession used in CSSL development. In addition, O. meridionalis has been reported to have drought tolerance and rare secondary branching. O. glumaepatula may provide a new cytoplasmic male sterility source for hybrid rice. The O. meridionalis (W2112) from Australia may provide interesting alleles for drought tolerance due to possible evolution of the species in semi-dry environment. The O. barthii (IRGC101937) has good potential as a donor for abiotic stress tolerance, especially if we consider the possibility of observing transgressive effects. The O. glumaepatula (GEN1233) was chosen for its good level of aluminum tolerance, which represents a promising trait for cultivating rice on acid soils. In addition, useful agronomic, biotic and abiotic traits from the wild rice species outside AA genome will also be utilized. For ABC and CSSL, each cultivar (M202, Nipponbare and Lagrue) is crossed to the following Oryza accessions: O. glaberrima (IRGC96717), O. barthii (IRGC105608), O. nivara (IRGC100897), O. rufipogon (IRGC106424), O. meridionalis (IRGC104085), O. glumaepatula (W2199), O. longistaminata (IRGC110404). For ABC, F1 hybrids are confirmed and advanced to BC2F2, genotyped, advanced to F3 and seed collected. The resultant lines will be used by collaborative US rice researchers for assessment and identification of useful alleles. For CSSL, introgressed segments of approximately 10cM are tracked. Following genotyping of 300 BC2F1 plants per segment, lines are advanced and backcrossed to the BC4F1, genotyped to confirm introgression segments and seed produced from the BC4F3 prior to release. For molecular genetic map construction of the ten distinct Oyrza genome groups, crosses are as follows: AA: O. glaberrima (IRGC 96717) x glaberrima (IRGC 103544), glaberr