Theoretical and Applied Genetics

, Volume 111, Issue 4, pp 619–629

The self-incompatibility locus (S) and quantitative trait loci for self-pollination and seed dormancy in sunflower

  • Sonali D. Gandhi
  • Adam F. Heesacker
  • Carrie A. Freeman
  • Jason Argyris
  • Kent Bradford
  • Steven J. Knapp
Original Paper

DOI: 10.1007/s00122-005-1934-7

Cite this article as:
Gandhi, S.D., Heesacker, A.F., Freeman, C.A. et al. Theor Appl Genet (2005) 111: 619. doi:10.1007/s00122-005-1934-7

Abstract

Wild populations of common sunflower (Helianthus annuus L.) are self-incompatible and have deep seed dormancy, whereas modern cultivars, inbreds, and hybrids are self-compatible and partially-to-strongly self-pollinated, and have shallow seed dormancy. Self-pollination (SP) and seed dormancy are genetically complex traits, the number of self-compatibility (S) loci has been disputed, and none of the putative S loci have been genetically mapped in sunflower. We genetically mapped quantitative trait loci (QTL) for self-incompatibility (SI), SP, and seed dormancy in a backcross population produced from a cross between an elite, self-pollinated, nondormant inbred line (NMS373) and a wild, self-incompatible, dormant population (ANN1811). A population consisting of 212 BC1 progeny was subsequently produced by backcrossing a single hybrid individual to NMS373. BC1 progeny produced 0–838 seeds per primary capitula when naturally selfed and 0–518 seeds per secondary capitula when manually selfed and segregated for a single S locus. The S locus mapped to linkage group 17 and was tightly linked to a cluster of previously identified QTL for several domestication and postdomestication traits. Two synergistically interacting QTL were identified for SP among self-compatible (ss) BC1 progeny (R2=34.6%). NMS373 homozygotes produced 271.5 more seeds per secondary capitulum than heterozygotes. Germination percentages of seeds after-ripened for 4 weeks ranged from 0% to 100% among self-compatible BC1S1 families. Three QTL for seed dormancy were identified (R2=38.3%). QTL effects were in the predicted direction (wild alleles decreased self-pollination and seed germination). The present analysis differentiated between loci governing SI and SP and identified DNA markers for bypassing SI and seed dormancy in elite × wild crosses through marker-assisted selection.

Supplementary material

122_2005_1934_ESM_supp.pdf (155 kb)
(PDF 156 KB)

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Sonali D. Gandhi
    • 1
  • Adam F. Heesacker
    • 1
  • Carrie A. Freeman
    • 1
  • Jason Argyris
    • 2
  • Kent Bradford
    • 2
  • Steven J. Knapp
    • 3
  1. 1.Department of Crop and Soil ScienceOregon State UniversityCorvallisUSA
  2. 2.Department of Vegetable CropsUniversity of CaliforniaDavisUSA
  3. 3.Center for Applied Genetic TechnologiesThe University of GeorgiaAthensUSA

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