Poster: Hormones

Abs # 646: Double Haploid Technology to Develop Near-Isogenic Lines of Wild Mustard (Sinapis arvensis L.) with Auxinic Herbicide Resistance and Susceptibility

Presenter:	Jugulam, Mithila , mjugulam@uoguelph.ca
Authors	Jugulam, Mithila  (A)   Hall, J C (A)
Affiliations:	(A): University of Guelph

The mechanism of resistance to auxinic herbicides remains to be uncovered after 60 years of agricultural use. The discovery of a wild mustard biotype in western Canada that is resistant to a combination of auxinic herbicides has provided an opportunity to study the mechanism of resistance to auxinic herbicides. Classical genetic analyses of auxinic herbicide resistance in wild mustard indicate that resistance is controlled by single dominant allele. However, the development of near-isogenic lines will help to map the precise role of the auxinic herbicide resistance gene(s) in wild mustard. To hasten the production of near isogenic lines, double haploid technology was used. Heterozygous plants of Sinapis arvensis expressing the auxinic herbicide-resistance trait were generated through conventional breeding methods and screened for resistance to the auxinic herbicide picloram. Microspore cultures were initiated from these heterozygous plants and preliminary results indicate the possibility of development of haploids through pollen embryogenesis. Haploid production from heterozygous plants should produce homozygous resistant or susceptible plants in a 1:1 ratio upon colchicine treatment. These double haploids will be subsequently used for production of near-isogenic lines through a series of back crosses. Near-isogenic lines can assist in the genetic and molecular analyses of auxinic herbicide resistance, thereby providing valuable information about the genetic basis of auxinic herbicide resistance in wild mustard.