Location: Plant Genetics ResearchTitle: Reconstruction of the synthetic W9784 x Opata85 wheat reference population) Author
Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2011
Publication Date: N/A
Citation: Interpretive Summary: In the late 1980’s, the International Maize and Wheat Improvement Center (CIMMYT), Mexico, and Cornell University, Ithaca collaborated to survey polymorphism levels among a large number of diverse wheat (Triticum aestivum L.) germplasm lines. Eventually, the synthetic W7984 (Altar84/Ae. tauschii (219) CIGM86.940) x Opata M85 population was selected and seed from only 150 F2’s were advanced to the F7 generation. Small quantities of seed from that generation were distributed to several collaborators on a world wide scale. The population has been referred to by several names including M6 x Opata, SYOP, Synthetic x Opata, and ITMI population. This population was widely used around the world as a reference population for mapping markers. Reference populations are used in genetic studies of crop species for determining marker order, marker selection, trait mapping, construction of large-insert libraries, cross-referencing marker platforms and genome sequencing. Over the years since it was constructed, the W7984 x Opata 85 population was freely distributed and re-distributed to many researchers around the world and over time anomalies have accumulated because of outcrossing, labeling errors, genetic drift and chromosomal instability. Consequently, the goal of this work was to re-establish two new reference populations using the same parents as the original population taking extra precautions to minimize the reoccurrence of anomalies. Two complementary populations were produced; a population of 215 doubled haploids designated SynOp-DH and a recombinant inbred population consisting of 1700 F6 derived lines designated SynOp-RIL. The purpose of these populations is to provide a resource for both coarse and high resolution mapping, that is highly polymorphic, has known characteristics, and is available in the public domain.
Technical Abstract: Reference populations are a valuable resource in genetics studies of crop species for determining marker order, marker selection, trait mapping, construction of large-insert libraries, cross-referencing marker platforms, and genome sequencing. Useful reference populations can be propagated indefinitely, have a high level of polymorphism, and predominantly regular segregation. Two new reference populations using the same parents as the original W7984 (Altar84/Aegilops tauschii (219) CIGM86.940) x Opata M85 wheat reference population are described, one of which is a doubled haploid population (SynOp-DH) of 215 and the second is a recombinant inbred population (SynOp-RIL) of 1700 lines. A linkage map was constructed for the SynOp-DH population using 1446 DArT markers and 59 simple sequence repeat (SSR) or sequence tagged site (STS) markers. In addition, a core set of 42 SSR markers were genotyped on the SynOp-RIL population. A new approach to identifying a core set of SSR markers used a step-wise selection protocol based on polymorphism, chromosome distribution, and reliability to create nested sets starting with one per chromosome followed by two, four and six. It is recommended researchers use these markers as anchors for all future mapping projects to facilitate cross-referencing markers and chromosome locations. Researchers are encouraged to validate the identity of each line using the morphological data and marker information to ensure accurate genotypes. To enhance this public resource, researchers are strongly urged to deposit their data in GrainGenes so that others can benefit from the accumulated information.