Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2001
Publication Date: N/A
Technical Abstract: The USDA-ARS/Texas A&M University rice varietal improvement program has released 34 cultivars over the last seven decades. Since 1992 the program has used molecular genetics to develop new cultivars for the US rice industry. Several simply inherited traits common to most rice breeding programs were chosen as the initial targets for marker development. Markers slinked to five genes conferring resistance to rice blast disease have been developed and are used to combine these genes in breeding lines. Markers have also been developed for amylose content, grain aroma, and cooked kernel elongation which influence rice quality. Grain amylose content is the single most important cooking and sensory quality factor in rice and is largely controlled by the Waxy gene. A microsatellite marker closely linked with this gene is now routinely used to screen thousands of genetic lines from public rice research programs as an indicator of market class and cooking quality. PCR based genetic markers associated with popcorn aroma found in scented rices and cooked kernel elongation found in basmati-type rices will be useful in developing cultivars for these specialty markets. Using molecular breeding techniques, 3 to 5 years were saved in the development of the cultivars Cadet and Jacinto. Markers are also routinely used in the breeding program to verify hybridizations for quality control in seed purification fields.