CHROMOSOME MANIPULATION IN THE GRAMINAE

Much of the work proposed under this project is curiosity-driven, with one substantial caveat: that its products must be useful in agriculture. PI tries to anticipate breeders' needs and prepare in advance chromosome constructs with new genes/loci for resistance to pests and diseases, or new germplasm capable of meeting new requirements or changing conditions. At other times, he responds to breeders wishes and creates stocks to meet specific needs. Along these lines, new hybrids of turfgrasses are created and tested under realistic management conditions; new chromosome constructs are created to address specific needs, such as a workable system of male sterility and fertility restoration in wheat and triticale, haploid production, or new combinations of alleles of storage protein genes. These chromosome constructs are also very useful in addressing questions of general biological significance. In the upcoming period the PI hopes to address the issue of chromosomal instability in newly formed amphiploids.While this proposal covers the next five years, the project is open-ended. Projects evolve over time; each answered question brings more questions. The general theme is understanding of chromosome behavior, mostly in meiosis. Each experiment brings in some small piece of the puzzle but realistically, it does not appear likely that the issues associated with chromosome pairing and crossing over will be resolved in the foreseeable future.Specific objectives are:1. Continue manipulation of crossing over, particularly in transfers of chromosome segments with agronomically valuable loci from related species to wheat. 2. study the relationship, if any, of the centromere size and female transmission rates of chromosomes in wheat3. seek explanations for chromosomal instability of wide hybrids; specifically, the role of the attachment of telomeres to the nuclear membrane in pairing initiation4. create chromosome constructs for specific agricultural uses, such as cytoplasmic male sterility in wheat and triticale, enhanced drought tolerance, disease and pest resistance5. map locus/loci on chromosome arm 1RS responsible for haploid induction in the Ae. kotschyi cytoplasm6. continue selection for large glumes and grain size in durum x T. polonicum hybrids7. create population ryes with introgressions of Rht8 and Ppd1 from bread wheat and test the effects of the introgression of wheat storage protein loci on flour parameters of rye8. create custom made cytogenetic stocks for others, as needed9. continue selection of wide hybrids in Cynodon, and among kikuyu grass for desired turf characteristics, especially for drought tolerance and reduced winter dormancy, better winter color retention, etc.