Plant & Animal Genome IX Conference

Workshop: Compositae
W19_06.html

THE DEVELOPMENT OF DNA MARKERS FOR HIGH-THROUGHPUT GENOTYPING IN CULTIVATED SUNFLOWER: LENGTH POLYMORPHISMS AND GENETIC MAPPING OF SIMPLE SEQUENCE REPEATS AMONG RECOMBINANT INBRED LINES

Department of Crop and Soil Science, Oregon State University, Corvallis, OR 97331-3002, USA

The genetic map of cultivated sunflower (Helianthus annuus L.) (x = 17) is sparsely populated with simple sequence repeat (SSR) and other high-throughput genetic markers. The development of 454 simple sequence repeat (SSR) markers from GA- and CA-enriched genomic DNA libraries and genetic mapping of 254 SSR markers in a recombinant inbred line (RIL) mapping population (RHA280 x RHA801) are described herein. Eight hundred and thirty-eight genomic DNA clone inserts were sequenced. Of these, 758 (91%) harbored SSRs ranging in length from 10 to 128 bp. One hundred and eighty-nine redundant sequences (23%) were identified; thus, 68% of the clones harbored unique SSRs. Flanking primer pairs were designed for 524 unique repeats. Of these, 70 (14%) failed to produce amplicons or produced complex amplicons, while 454 (86%) produced amplicons of the predicted lengths and were screened for length polymorphisms between RHA280 and RHA801 on an ABI377. Two hundred and six (45%) SSRs were polymorphic and were mapped along with another 48 SSRs. Two hundred and ninety-one SSR markers, 44% of which were dominant, have been placed on the RHA280 x RHA801 map thus far; 30 duplicate loci were mapped. The high percentage of null alleles suggests that the primer annealing sites flanking SSRs are frequently highly polymorphic in sunflower. Because of the length of the genetic map and intermediate frequency of SSR length polymorphisms, additional SSR markers are needed to routinely construct 'complete' genetic maps in sunflower.