Submitted to: Rice Utilization Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 1, 1999
Publication Date: N/A
Technical Abstract: Rice milling quality is comprised of total whole grain milling yield (MYD) and degree of milling. Producer's income is strongly impacted by the amount of whole grain rice obtained after milling their crop. Many traits such as kernel shape are thought to impact MYD but few have been verified. It is difficult to select for MYD early in the breeding process because of segregation and the large environmental impact on this trait. The development of hybrid rice and the use of high yielding foreign germplasm to develop new cultivars have been hindered by low MYD. Understanding the genetics controlling MYD would assist breeders in these efforts. The purpose of this research was to identify genomic regions associated with traits affecting MYD in a population derived from a Lemont x Teqing cross. A population of 284 recombinant inbred lines were developed from a Lemont x Teqing cross. RFLP probes (175) were screened against the parental and line's DNA. Kernel morphology and MYD were evaluated on samples of the population grown in 1997. Analysis identified eight chromosomal regions associated with MYD. Two of these loci that were associated with MYD are of particular interest because they are apparently independent from grain shape, and may be affecting grain hardness. These two loci each accounted for 6-8 percent of the total variance observed in percent head rice in 1997. This would translate into a 4 percent increase in head rice resulting from the incorporation of a single gene into a new variety. These results will need to be verified by analyzing samples grown in several more locations.