|Ali, M. Liakat -|
|Mccouch, Susan -|
Submitted to: International Plant and Animal Genome IX Conference
Publication Type: Abstract Only
Publication Acceptance Date: November 30, 2012
Publication Date: December 10, 2012
Citation: Eizenga, G.C., Ali, M., Mccouch, S.R. 2012. Developing rice mapping populations as a genetic resource for validation of GWAS. International Plant and Animal Genome Conference. XXI. San Diego, CA - January 12-16, 2013. Technical Abstract: Asian rice (Oryza sativa L.) is divided into two major subspecies, Indica and Japonica with the temperate and tropical japonica subpopulations being part of Japonica. These two subpopulations encompass the majority of the rice grown in the USA. Recently, a genome-wide association study (GWAS) identified SNP markers associated with 32 traits of agronomic importance. To validate these associations, four bi-parental recombinant inbred line (RIL) populations are currently under development using Japonica parents that were divergent for several of the traits evaluated. Two populations (Estrela x NSFTV 199; Norin 20 x Fortuna) were evaluated in the field during summer 2012 in an unreplicated study to observe the phenotypic variation and produce enough seed for replicated field studies. Transgressive variation was observed for days to heading, plant height and plant type (tiller angle). Data on panicle and seed traits (panicle length, primary panicle branch number, seeds per panicle, seed size) are currently being collected. This year, F7 progeny lines will be genotyped using genotyping-by-sequencing (GBS). Several double cross F1 seeds were produced from crosses between two different bi-parental F1 hybrids. These double crosses had parents representing the following subpopulation groups: tropical japonica and indica; tropical japonica and temperate japonica; and tropical japonica, temperate japonica and indica. Currently crosses are being made between several of these double cross F1 progeny plants to develop multi-parent advanced generation inter-cross (MAGIC) populations with four parents as founder lines. After genotyping by GBS, these MAGIC populations will be used to investigate quantitatively inherited traits of agronomic importance using GWAS and fine mapping to better understand the genetic basis of transgressive variation for the traits.