Breeding for disease resistance
Sclerotial diseases of rice
Wild species of rice
Seedling vigor
Seedling diseases of rice
Rice diseases
Gene tagging and mapping (in cooperation with UC Davis and USDA)
RESEARCH STATEMENT:
Breeding for resistance to stem rot (caused by Magnaporthe salvinii), aggregate sheath spot (caused by Ceratobasidium oryzae-sativae), bordered sheath spot (caused by Waitea circinata), and seedling diseases (caused by Achlya and Pythium spp.) is the focus of my research. All advanced breeding material is evaluated for level of resistance to the sclerotial diseases in an inoculated nursery. Wild species of rice have been used as sources of higher resistance to the sclerotial diseases. Italian and Russian varieties with high vigor have been used to mitigate stand establishment problems caused by the watermolds. Additional benefits of high seedling vigor are better competitiveness against weeds, advantages in timing of herbicides, and the possibility of greater water depths during stand establishment.
No varieties are yet available with resistance to the sclerotial diseases or with high vigor. Resistance appears to be associated with a range of undesirable traits, especially in the medium and short grain part of the program. However, resistant long grain breeding lines have been developed which yield as high as current long grain varieties. Unfortunately, one or more agronomic deficiencies have prevented their release as varieties. One has been released as germplasm (PI 566666).
Recently, tagging and mapping stem rot resistance genes from Oryza rufipogon 100912 have been undertaken in cooperation with Dr. Dave Mackill, USDA Geneticist stationed at UC Davis. Nine markers have so far been found associated with stem rot resistance. Three markers have been located on three separate chromosomes and research continues for the remaining markers. This resistance is also effective against the sheath spots.
Most recently, crosses have been made with wild species having even higher levels of resistance to the sclerotial diseases. Field trials of this material will soon begin.
AFFILIATIONS:
Member of Rice Crop Germplasm Committee
Member of American Phytopathological Society
Member of Rice Technical Working Group
SELECTED PUBLICATIONS:
Oster, J.J. 1990. Screening techniques for stem rot resistance in rice in California. Plant Dis. 74:545-8.
Oster, J.J. 1992. Reaction of a resistant breeding line and susceptible California rice cultivars to Sclerotium oryzae. Plant Dis. 76:740-4.
Oster, J.J. 1994. Effect of seeding rate in plots and rows on screening for stem rot and sheath spot resistance from Oryza rufipogon. p. 105. In Proc. 25th Rice Tech. Wrkg. Grp., New Orleans,LA.
Oster, J.J. 1996. Effects of Temperature and water molds on screening for seedling vigor in rice in California. p.---. In Proc. 26th Rice Tech. Wrkg. Grp., San Antonio, TX.
Rutger, J.N., R.A. Figoni, R.K. Webster, J.J. Oster and K.S. McKenzie.1987. Registration of early maturing, marker gene, and stem rot resistant germplasm lines of rice. Crop Sci. 27: 1319-20.
Tseng, S.T. and J.J. Oster. 1994. Registration of 87-Y-550, a rice germplasm line resistant to stem rot disease. Crop Sci. 34:314.
| DEGREE/POSITION | INSTITUTION | YEAR | SPECIALITY |
| Bachelor of Science | University of California, Berkeley | 1975 | Plant Pathology |
| Masters of Science | Washington State University | 1977 | Plant Pathology |
| Staff Research Associate | University of California, Riverside | 1977 | Plant Pathologist |
| Plant Pathologist | California Coop. Rice Res. Foundation | 1980 | Rice Pathology |
Last Update: 06/21/2002