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Rice Research Proposal

Rice research at RES will continue toward the primary objective of developing improved rice varieties for California.

Project leaders will concentrate efforts on developing rice varieties for the traditional medium, short, and long- grain market classes. Research efforts will continue to improve and develop specialty rice such as waxy (mochi or sweet) rice, aromatic rice, and others as an adjunct breeding effort. Major breeding emphasis will continue on improving grain quality, yield and disease resistance. Efforts will be made to effectively use new as well as proven breeding, genetic, and analytical techniques. RES staff will expand DNA marker screening capabilities. Following are the major research areas of the RES Rice Breeding Program planned for short, medium, and long-grain types.


Efforts to identify, select, and improve culinary and milling quality in all grain types will continue to receive major emphasis. Improved cooking evaluation techniques are being used that include use for DNA markers for amylose content, gelatinization temperature, and RVA profiles. The RES quality lab is being renovated to support quality evaluation and research for variety development.

Resistance to Disease

The RES Rice Breeding Program is continuing efforts to improve disease resistance in our California varieties. Evaluation and screening for stem rot and sheath spot resistance will be conducted by the plant pathologist on segregating populations, advanced breeding lines, and current varieties. Rice blast disease presents an additional threat to California. Research and breeding activities to address rice blast to develop improved blast resistant varieties will continue. Materials from backcrossing efforts to transfer disease resistance have been transferred to the breeding projects for evaluation. New resistant sources and foreign germplasm will continue to be evaluated as potential parental material. Foreign germplasm will be introduced through quarantine for use in breeding and research.


Yield is a complex character that results from the combination of many agronomic traits. Emphasis will continue on breeding varieties with high grain yield potential, minimal straw for high yield, and more stable yields while maintaining and/or improving grain quality.

Tolerance to Low Temperature

Tolerance to low temperature remains an essential character needed at seedling and reproductive stage in California rice varieties. Segregating populations and advanced experimental lines will continue to be screened in the San Joaquin nursery for resistance to blanking, normal vegetative growth, a minimum delay in maturity, and uniform grain maturity. Selection at UCD has been discontinued due to concerns about adjacent UC research activities. Cold tolerance data will include two seeding dates of advanced material at RES, UCCE Statewide Yield Tests, refrigerated greenhouse tests, and data from cold tolerance and the Hawaii winter nurseries.

Lodging and Maturity

Improved lodging resistance will receive continued emphasis in all stages of variety development. Efforts will continue to develop improved varieties that have a range of maturity dates with major emphasis placed on early, very early maturity, synchronous heading, and uniformity of ripening.

Other Areas

The program will continue to look for mutants with herbicide tolerance or resistance as well as characterizing varietal differences in response to rice herbicide for screening purposes.

Cooperative Projects

Cooperative research by the rice breeding program staff with USDA, UC, The Temperate Rice Research Consortium, and others in the area of biotechnology, genetics, quality, agronomy, entomology, plant pathology, and weed control will be continued in 2012. Emphasis will be placed on applied research and more basic studies that may contribute to variety improvement for California.

Rice Research Priorities and Areas of Breeding Research

General Rice Research Objectives of Rice Experiment Station

The primary research objective of RES is the development of high yielding and quality rice varieties of all grain types (short, medium, long) and market classes to enhance marketing potential, reduce cost, and increase profitability of rice. Rice breeding research priorities at RES can be divided into general priorities that are applicable to all rice varieties developed for California, and specific priorities that may differ between grain types, market classes, special purpose types, and the special interests of the plant breeding team members.

A secondary but important objective is to support and enhance UC and USDA rice research through cooperative projects and by providing land, water, and input resources for weed control, insect, disease, and other disciplinary research.

General Rice Breeding Priorities Applicable to All Public California Rice Varieties

 High and stable yield potential

 Disease resistance

 Cold tolerance and seedling vigor

 Early maturity and lodging resistance

 Synchronous heading and maturity

 Improved head rice milling yields

 High quality rice consistent with grain type, market class, or special use

 Develop and utilize DNA marker assisted selection

Specific Rice Breeding Priorities by Grain Type, Market Class, and Special Use

Calrose Type Medium Grains

 Improve Calrose medium grains

 Improve stem rot resistance in medium grains

 Improve blast resistance in medium grain

 Increase yield potential, cold tolerance, and genetic diversity

 Explore opportunities to provide herbicide tolerance

Premium Quality, Short Grains, and Medium Grains

 Improve California short grain rice

 Develop superior premium quality short and medium grain varieties

 Improve waxy, low amylose, and bold grain rice

 Use DNA markers for grain quality and disease resistance breeding

Long Grains

 Superior quality for table and processing

 Improve head rice milling yields and fissuring resistance

 Improve basmati types

 Develop jasmine types

 Improve aromatic types

 Improve cold tolerance

Rice Pathology

 Screening and evaluation of advanced breeding lines for blast, stem rot, and sheath spot.

 Facilitate transfer of stem rot and aggregate sheath spot disease resistance from wild species of rice and disease resistance genes identified in RiceCAP

 Mapping of stem rot resistance genes and marker aided selection for stem rot and blast

 Facilitate germplasm introduction and pathology related research