Location: Hard Winter Wheat Genetics Research2013 Annual Report
1a. Objectives (from AD-416):
Develop wheat germplasm lines with resistance or tolerance to wheat rusts, Fusarium head blight, pre-harvest sprouting, heat stress, or drought stress. Construct and analyze populations to identify genes controlling these traits. Develop improved genotypic or phenotypic selection technologies for these traits.
1b. Approach (from AD-416):
Association mapping populations have been constructed and are now being analyzed. For genotyping, we will use conventional SSRs, STS, and SNP markers and a genotyping-by-sequencing (GBS) approach suitable for the large complex genomes of wheat. Genotyping-by-sequencing uses restriction enzymes to produce a reduced representation of the genome that is then multiplex sequenced on the Illumina platform using DNA barcode adapters. We are able to identify tens of thousands of SNPs in each sample and use this information for genetic mapping and breeding. We will use the GBS data to identify SNP markers closely linked with the resistance genes while making background selection for the recurrent parent genotype. This marker assisted back-crossing approach will 1) identify molecular markers linked to traits of interest and 2) rapidly recover the elite wheat background for using these genes in breeding.
3. Progress Report:
Susceptibility to heat stress is one of the most important constraints on wheat yields. Seeds were collected from 24 crosses made between heat-tolerant and heat-susceptible wheat lines selected in the previous year by screening 304 members of the Triticeae Coordinated Agricultural Project (TCAP) winter wheat association mapping panel. One cross (OK06114 x Wendy) was used to produce doubled haploid lines. Another cross (HV9W03 x TX04M410164) was advanced to the F3 generation using the single seed descent method. Twenty-seven crosses were also made between 7 tolerant and 4 susceptible lines from the TCAP spring wheat association mapping panel. These biparental populations will be tested for heat tolerance in growth chambers and will be genotyped for high density DNA markers. Genes that control heat tolerance will be mapped to individual chromosomes using standard quantitative trait mapping procedures. One of the difficulties faced by breeding programs is collecting and managing huge amounts of field notes with rapid turnaround times and low error rates. An application was developed for hand-held Android(TM) tablets that can be used as a replacement for paper field books. The ‘Field Book’ application is very flexible and can be used to record a variety of numeric, percentage, Boolean, date, and text data in a suitable format for field plot research. Data can then be uploaded to a local computer or to a cloud-based server.