1a.Objectives (from AD-416)
The goal of the proposed project is to transfer an identified gene for rust (Puccinia helianthi) resistance into an acceptable confectionery sunflower genetic background and make it available to the private seed industry for incorporation into finished commercial hybrids.
1b.Approach (from AD-416)
Three known rust resistance genes, R2, R5, and Radv, will be introduced into suitable confectionery sunflower inbred lines. Sunflower line CM29 containing the R2 gene will be crossed with inbred line CONFSCL B1; line HAR-2 containing the R5 gene will also be crossed with inbred line CONFSCL B1; and line RHA 340 containing the Radv gene will be crossed with line CONFSCL R5. Both the CONFSCL B1 and CONFSCL R5 lines are confectionery sunflower inbred lines with resistance to Sclerotinia disease. The progeny of these crosses will be planted for further backcrossing in the summer 2010 season. The goal for the first year of this projected three-year project is to have the BC1 (first backcross generation) available for planting in the greenhouse in the winter of 2010-11 for production of the BC2 (second backcross generation). At each generation, the progeny will be screened for rust resistance. In addition, DNA markers representative of the parental CONFSCL B1 and CONFSCL R5 lines will be identified and used to screen the progeny for retention of the confectionery character. This will allow us to discard at an early stage the progeny that do not carry the important traits characteristic of confectionery sunflower. This should allow us to develop pure inbred lines with rust resistance after only a few generations, and the lines can be released to the sunflower seed industry by 2012.
The goal of the proposed project is to improve Sclerotinia stalk rot resistance in the cultivated germplasm. To date we have already developed eight BC2 populations from the crosses of HA 89 with resistant plants selected from annual H. argophyllus, H. debilis, H. praecox, and H. petiolaris. Five-hundred sunflower SSR markers selected from the sunflower genetic maps were used to screen the polymorphism between HA 89 and wild annual species in order to monitor the introgressed traits in cultivated sunflower. Eight thousand SNP markers were used to genotype 260 cultivated sunflower Plant Introductions (PIs). Association mapping analysis is being conducted using our existing stalk rot infection data from several location-years and our genotype data from 8,000 random SNPs on our 260-line panel.