2010 Annual Report
1)compare the effectiveness of physical and chemical mutagens in generating point mutations in japonica and indica rice,.
2)determine the genetically effective cell number in rice, and.
3)develop an efficient mutagenesis protocol for producing rice mutant populations for reverse and forward genetics. It is expected that the completion of these objectives will provide basic knowledge on the appropriate mutagens to use in order to efficiently generate induced mutant populations for basic and applied research on rice improvement. An effective protocol for japonica and indica rice subspecies will benefit researchers interested in developing populations in germplasm and breeding materials relevant to their respective environments. During FY10, work continued on the assessment of mutation rates and the determination of genetically effective cell number (GECN) from materials that were subjected to various mutagenic treatments in FY08/09. Treatments included sodium azide (1 mM) only, sodium azide plus methyl nitrosoureas (1 mM and 15 mM respectively), ethyl methanesulfonate (1.5%) and gamma-irradiation (300 grays). In FY10, M2 generation seeds were threshed from M1 generation panicles from about 100 plants from each treatment. These seeds will be planted in July 2010 to assess the mutation rate generate by each mutagenic treatment and the GECN. In addition, an experiment was initiated to examine the effect of soaking seeds (imbibition) prior to exposure to chemical mutagens (i.e., ethyl methanesulfonate) on mortality and mutation rates. Additional mutagenic treatments have been carried out in FY10 primarily using the variety Kitaake, an early maturing japonica rice easily grown in the greenhouse, and another variety, 29Lu1, an early maturing indica rice has been obtained for use in our experiments to facilitate more rapid analyses. Work on ultrahigh throughput sequencing of mutants to assess mutation rates is expected to be initiated prior to the end of FY10. The ADODR monitors this NFCA by maintaining a complete file of the agreement, reviewing the annual reports, and conducting meetings with the cooperator during the course of the agreement.