Submitted to: Agricultural Experiment Station Publication
Publication Type: Experiment Station
Publication Acceptance Date: 6/1/2011
Publication Date: 6/15/2011
Citation: Jia, Y., Bryant, R.J., Jia, M.H., McClung, A.M., Liu, G., Oard, J., Correa, F. 2011. Release of four new breeding lines having resistance to blast and sheath blight diseases. Texas Rice Special Section, Highlighting Research in 2011. p. VIII-IX. Interpretive Summary:
Technical Abstract: Sheath blight and rice blast diseases are serious threats to rice production worldwide. High-yielding cultural management practices, such as high nitrogen application and high plant populations, encourage development of these diseases. Complete resistance to sheath blight has not been identified, although there are major genes that offer complete resistance to specific races of the blast pathogen. Resistance to blast disease has not been durable in some regions due to the development of new races of the pathogen that overcome the deployed resistance genes. We have developed four germplasm lines that possess multiple genes for resistance to sheath blight and blast diseases. These lines [LJRIL103 (PI 660982), LJRIL158 (PI 660983), LJRIL186 (PI 660984), and LJRIL220 (PI 660985)] were developed from a cross of Lemont and Jasmine 85. They were selected from a population of 256 progeny and were screened in greenhouse and mist chamber inoculation tests, and resistance was confirmed in field trials. The greenhouse sheath blight evaluation methods were developed as part of the USDA NRI RiceCAP research project that resulted in mapping novel resistance genes for sheath blight in this and other genetic populations. All four germplasm lines have sheath blight resistance comparable to the resistant parent Jasmine 85. They contain various combinations of blast resistance genes from both parents, with LJRIL186 having better blast resistance than either parent. They are all long grain varieties with amylose content similar to Lemont, and three of the four lines are aromatic. The germplasm lines are well-adapted for production in the southern USA based upon their plant height, maturity, and plant type. These germplasm lines were jointly released by the USDA-ARS, University of Arkansas Rice Research and Extension Center, Stuttgart, AR, International Center for Tropical Agriculture, Cali, Colombia, and the LSU AgCenter, Baton Rouge, LA. They are being made freely available to the public and will be important in the development of disease-resistant aromatic and conventional long grain varieties for the US rice industry.