Mapping of QTL controlling tocopherol content in winter oilseed rape


Marwede V., Gul M., Becker H., Ecke W.

PLANT BREEDING, vol.124, no.1, pp.20-26, 2005 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 124 Issue: 1
  • Publication Date: 2005
  • Doi Number: 10.1111/j.1439-0523.2004.01050.x
  • Title of Journal : PLANT BREEDING
  • Page Numbers: pp.20-26

Abstract

Tocopherols are natural antioxidants in vegetable oils and are important dietary nutrients. Enhanced tocopherol content has become an important objective in oilseed rape breeding. A segregating DH population was tested for 2 years at two locations in replicated field trials. Genotypic differences occurred for alpha-, gamma- and total tocopherol content as well as alpha/gamma-tocopherol ratio, but highly significant genotype x environment interactions resulted in low heritabilities. Using a mixed-model composite interval mapping approach between one and five QTL with additive and/or additive x environment interaction effects could be mapped for alpha-, gamma- and total tocopherol content and alpha/gamma-tocopherol ratio. In addition, one to six locus pairs with epistatic interaction effects were identified, indicating a strong contribution of epistasis to trait variation. In total, the additive and epistatic effects explained between 28% (alpha-tocopherol content) and 73% (total tocopherol content) of the genotypic variance in the population, with individual QTL and locus pairs contributing between 7.5 and 29.2% of variance. Considering the low heritabilities of the tocopherol traits, the results of this study indicate that marker-assisted selection may be an efficient strategy in a breeding program for enhanced tocopherol content in rapeseed.