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United States Department of Agriculture

Agricultural Research Service

Germplasm Evaluation and Enhancement
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Current Personnel

   WenGui Yan,, Geneticist

Tiffany Sookaserm, Biological Science Technician

Tyler Teske, Biological Science Technician

Wei Zhou, Ph.D., Post-Doctoral Scientist

Haizheng Xiong  Ph.D. Candidate


 Acknowledgement of the direct contributors to this program.

Germplasm Regeneration and Evaluation
Dr. WenGui Yan harvesting rice plants with hand sickle.  

Re-grow germplasm periodically to maintain viable seeds of more than 18,000 accessions in the USDA rice world collection for public use, and more than 33,000 accessions in the Genetic Stocks Oryza Collection (GSOR) and evaluate 32 characteristics to enrich the genebank in the Germplasm Resources Information Network (GRIN)

Click here to download a 3-minute slideshow which provides more information about the germplasm evaluation program.  NOTE:  This large file takes a few minutes to open. 

Genetic Characterization of Global Rice Germplasm

1.  Genetic characterization of global rice germplasm for sustainable agriculture.  2012.  Book Chapter in Book

2.  Using minimum DNA marker loci for accurate population classification in rice.  2012.  Mol Breed  29:413-425

3.  Analysis of genetic structure in the USDA rice mini-core collection using the SQUAMOSA promoter-binding-like gene family.  2012. Rice Genom Genet  3(1):1-7

4.  Analysis on genetic diversity of phenotypic traits in rice (Oryza sativa) core collection and its comprehensive assessment.  2012.  Acta Agro Sin 38(5):829-839 (goes to a Chinese web site).

5.  Genetic variation and association mapping of silica concentration in rice hulls using a germplasm collection.  2011.  Genetica 139:1383-1398

6.  Genetic structure associated with diversity and geographic distribution in the USDA rice world collection.  2010.  Natural Sci 2:247-291

7.  Geographic description of genetic diversity and relationships in the USDA rice world collection.  2010.  Crop Sci 50:2406-2417

8.  Genotypic and phenotypic characterization of genetic differentiation and diversity in the USDA rice mini-core collection.  2010. Genetica 138:1221-1230

9.  Genetic diversity associated with conservation of endangered Dongxiang wild rice (Oryza rufipogon).  2010.  Genet Reso Crop Evol 57:597-609

10.  Genetic assessment of a mini-core developed from the USDA rice genebank.  2009.  Crop Sci 49:1336-1346

11.  Development and evaluation of a core subset of the USDA rice germplasm collection.  2007. Crop Sci 47:869-878

Click here to see additional information on genetic diversity.  Note:  Adobe Acrobat is required for pdf file.

Genetic Improvement of Grain Yield and Hybrid Rice

1.  DNA methylation affected by male sterile cytoplasm in rice (Oryza sativa L.) -  2013 Mol Breed 31:719-727,

2.  Unraveling the complex trait of harvest index with association mapping in rice (Oryza sativa L.) – 2012 PLoS ONE 7(1):e29350

3.  Mapping QTLs for improving grain yield using the USDA rice mini-core collection - 2011 Planta 234:347-361,

4.   Association mapping of stigma and spikelet characteristics in rice (Oryza sativa L.) – 2009 Mol Breed 24:277-292

5.  QTL analysis for resistance to preharvest sprouting in rice – 2008 Plant Breed 127:268-273

6.  Association mapping of yield and its components in rice cultivars - 2007 Mol Breed 19:341-356

7.  Production and heterosis analysis of rice (Oryza sativa L.) autotetraploid hybrids – 2007 Crop Sci 47:2356-2363 

8.  Cytogenetic studies on two F1 hybrids of autotetraploid rice varieties showing extremely high level of heterosis – 2007 Plant Sys Evo 267:205-213

Click here for more information on mapping yield traits.  Note:  Adobe Acrobat is required for pdf file.


Straighthead Disease - Germplasm and DNA Markers for Breeding
 Picture showing rice panicles affected by straighthead disorder.  

Straighthead is a physiological disorder of rice that causes in-complete development of panicles and floral sterility.  

1.  Development of genetic markers linked to straighthead resistance through fine mapping in rice - 2012 PLoS ONE 7(12):e52540


2.  Genetic diversity and relatedness of rice cultivars resistant to straighthead disorder – 2010 Plant Breed 129:304-312


3.  Association mapping of straighthead disorder induced by arsenic in Oryza sativa – 2009 Plant Breed 128:551-558


4.  Soil and plant minerals associated with rice straighthead disorder induced by arsenic – 2008 Agron J 100:1655-1661


5.  Differential response of rice (Oryza sativa L.) germplasm to straighthead induced by arsenic – 2005 Crop Sci 45:1223-1228 ECOLOGY, MANAGEMENT & QUALITY  

Click here to see a poster with additional information.  NOTE:  Adobe Acrobat Reader required for pdf file.

Limited Arsenic Content in Rice Grain

1.  Response of rice genotype to straighthead disease as influenced by arsenic level and water management practices in soil. 2013 Sci Total Envir 442:432-436


2.  Water management impacts on arsenic speciation and iron-reducing bacteria in contrasting rice-rhizosphere compartments – 2011 Envir Sci & Tec 45:8328-8335


3.  Microbial communities in rice rhizosphere altered by intermittent and continuous flooding in fields with long-term arsenic application – 2011 Soil Bol & Biochem 43:1220-1228


4.  Arsenic accumulation in rice grain as affected by cultivars and water management practices – 2011 Environmental Eng Sci 28(8):591-596


5.  Total grain-arsenic and arsenic-species concentrations in diverse rice cultivars under flooded conditions – 2010 Crop Sci 50:2065-2075 ECOLOGY, MANAGEMENT & QUALITY

Click here for more information on water and grain arsenic.  Note:  Adobe Acrobat is required for pdf file.

Disease Resistance and Crop Protection

1.  Allelic analysis of sheath blight resistance with association mapping in rice. 2012.  PLoS ONE 7(3): e32703


2.  Searching for germplasm resistance to sheath blight from the USDA rice core collection.  2011.  Crop Sci 51:1507-1517 BREEDING & GENETICS


3.  Characterization of Pi-ta blast resistance gene in an international rice core collection.  2010.  Plant Breed 129:491-501


4.  Identifying novel resistance genes in newly introduced blast resistance rice germplasm.  2006.  Crop Sci 46:1870-1878 GENETIC RESOURCES


5.  Red rice (Oryza sativa L.) plant types affect growth, coloration, and flowering characteristics of first and second generation crosses with rice.  2006.  Weed Tech 20 (4): 838-851


Click here for more information on sheath blight in the core collection.  Note:  Adobe Acrobat required for pdf file.


Rice Breeding and Nutritional Improvement

1.  A putative gene sbe3-rs for resistant starch mutated from SBE3 for starch branching enzyme in rice (Oryza sativa L.).  2012.  PLoS ONE 7(8): e43026


2.  Weed suppression potential of ‘Rondo’ and other indica germplasm lines. 2012.   Weed Tech 26:517-524 


3.  Short and erect rice (ser) mutant from ‘Khao Dawk Mali 105’ improves plant architecture. 2012.  Plant Breed 131:282-285


4.  'Rondo’, a long-grain Indica rice with resistances to multiple diseases.  2010.  J Plant Registration 4:131-136   


5.  A natural mutation in rc reverts white-rice-pericarp to red and results in a new, dominant, wild-type allele: Rc-g.  2008.  Theor Appl Genet 117 (4):575-580

Click here for more information on Rondo.  Note:  Adobe Acrobat is required for pdf file.


Last Modified: 9/26/2013