|SATER, HALEY - University Of Arkansas|
|MOLDENHAUER, KAREN - University Of Arkansas|
|MASON, RICHARD - University Of Arkansas|
|SIEBENMORGEN, TERRY - University Of Arkansas|
|BOYETT, VIRINIA - University Of Arkansas|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/2015
Publication Date: 11/16/2015
Citation: Sater, H.M., Moldenhauer, K.K., Mason, R.E., Pinson, S.R., Siebenmorgen, T., Boyett, V.A. 2015. Preserving rice quality: fine mapping and introgressing a fissure resistance locus. ASA-CSSA-SSSA Annual Meeting Abstracts. Minneapolis, MN, Nov. 15-18, 2015. Paper number 94498.
Technical Abstract: Rice (Oryza sativa L.) kernel fissuring is a major concern of both rice producers and millers. Fissures are small cracks in the rice kernels that increase the percentage of breakage among the kernels when they are transported and milled, which decreases the value of processed rice. This study employed molecular gene tagging methods to fine map the fissure resistance (FisR) loci found in ‘Cybonnet’, a semidwarf tropical japonica cultivar, as well as accomplish the transfer of this trait to rice genotypes of standard plant height. This recombination of the fissure resistance trait is particularly significant in that one of the three previously-identified FisR loci resides near the semidwarf sd1 locus on the long arm of chromosome 1. This study began with F2 progeny from a cross between a conventional-height (Sd1Sd1) U.S. inbred cultivar with high kernel breakage upon milling, and Cybonnet, which is semidwarf (sd1sd1) and noted for having improved milling quality due to increased fissure resistance. Molecular markers (SSRs) within the three genomic regions previously determined to contain QTLs affecting kernel fissure resistance were used to identify F2 progeny plants containing recombination within region of chromosome 1 previously found to contain the FisR locus qFIS1-2 as well as sd1 so that the qFIS1-2 locus could be mapped more precisely. Ten individual plants were selected and advanced to F2:3 based on the following criteria: 1) the individual possessed recombination in the chromosomal region found to contain both the Sd1 and qFIS1-2 loci, 2) the individual maintained at least one standard height allele (i.e. was either Sd1Sd1 or Sd1sd1) and 3) when possible, the individual was homozygous for the other two known FisR QTLs that are not closely linked to sd1. To reduce the time and labor required for phenotyping, the F2:3 progeny are being genotyped prior to being phenotyped, such that only individuals found to be homozygous for the new recombination are to be analyzed for fissure resistance. To date, progeny from two of the ten populations have been phenotyped. Results from both populations indicate that the qFIS1-2 locus is approximately 4 cM distal to sd1 on chromosome 1. This study provides further evidence that the previously identified QTL qFIS1-2 for fissure resistance is linked to but not pleiotropic with the sd1 allele and can be introgressed into rice of standard height.