Haploid Breeding Technique for Flax1

Abstract

A haploid breeding technique for flax (Linum usitatissimum L.) using a twin seedling character is described. The haploid twin can be distinguished from the diploid twin by seedling size 3 days after germination, plant height at any growth stage, and by the production of sterile flowers. The twinning frequency of 54 random entries from the USDA World Flax Collection was 1 set to 5,869 normal seed; a workable level in a flax cultivar development program. Use of a flax rust [Melampsora lint (Ehrenb.) Lev.] resistance marker gene showed the haploid twin to be of maternal origin, presumably produced by apogamety. In a breeding program this indicates haploid selection and doubling could be conducted in the F2 to allow for genetic recombination. A 16‐month breeding program to produce completely homozygous breeding lines ready for field evaluation is described. This developmental period includes screening for rust resistance and selection for oil content and quality.