VIEW ARTICLE

Resistance

Gene K¹ of Raja Flax: A New Factor for Resistance to Rust. J. A. Hoes, Plant pathologist, Agriculture Canada, Research Station, Morden, Manitoba, Canada R0G 1J0; E. O. Kenaschuk, flax breeder, Agriculture Canada, Research Station, Morden, Manitoba, Canada R0G 1J0. Phytopathology 76:1043-1045. Accepted for publication 14 April 1986. Copyright 1986 Department of Agriculture, Government of Canada. DOI: 10.1094/Phyto-76-1043.

The reactions to selected races of Melampsora lini of F₁, F₂, F₃, and testcross progenies of crosses between the flax cultivar Raja with the universal suscept Bison and five single-gene differentials (K, L⁶, M³, N¹, and P³) indicated that the resistance of Raja is monogenic, dominant, and is an allele at the K locus. The gene, designated K¹, is new and conditions resistance to all races of flax rust in North America. F₂ segregation data indicate that genes K¹ and N¹ are linked, with an estimated recombination percentage of 25%. Indications are that the K, N, and P loci, in the order indicated, are carried in the same chromosome. Gene K¹ appears to be derived from Argentine Selection 1025.