Plant & Animal Genomes XVI Conference

January 12-16, 2008
Town & Country Convention Center
San Diego, CA

Dissection Of Traits Relating To Flowering And Reproductive Frost Tolerance On Chromosome 2H Of Barley

Andrew Chen¹ , Ute Baumann¹ , Anita Brule-Babel² , Geoff B. Fincher¹ , Nick C. Collins¹

¹  Australian Centre for Plant Functional Genomics, University of Adelaide, Glen Osmond, South Australia, 5064, Australia

²  Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada

Sterility due to frost at flowering time periodically causes devastating losses to barley and wheat grain yields. Field screens had identified a locus on barley 2HL that influenced sensitivity to frost at the reproductive stage and which is distinct from all vegetative frost tolerance loci previously identified in the Triticeae. We aim to identify and characterize the genes and traits underlying the 2HL QTL effect. PCR markers were developed over 2HL, revealing a detailed view of the barley-rice co-linearity including 8 chromosome segments defined by inversion breakpoints. Recombinants from the high-resolution mapping population were phenotyped in a frost simulation chamber, using an experiment design that took in to account the truly quantitative nature of the tolerance. A plausible candidate for a frost tolerance gene was identified, based on map location, putative function and mRNA expression pattern. Flowering time is an important determinant of yield, because of its influence on factors such as water utilization and frost avoidance. Using the same mapping cross, we identified a locus distal of the putative frost tolerance QTL region on 2HL, which affects flowering time, eventual plant height and rachis internode length. It was mapped to a 3 cM interval and co-segregates with a gene representing an attractive candidate. Future work will explore the relationships between the earliness and frost sensitivity effects