Analyses of phenotypes of recombinants and revertants from testcross progenies involving genes at the L group, conferring resistance to rust in flax

When testcross progeny between lines carrying any two genes of theL group were analysed, rare susceptible and modified recombinants were recovered. Further, some susceptible recombinants yielded rare resistant plants (revertants) in their progeny. A total of 39 recombinants and 5 revertants were analysed for their reaction to a maximum of nine rust strains each avirulent on genes involved in their origin. The data showed that: a) Some of the rare recombinants represent new specificities. b) Reaction of a recombinant to a particular rust strains is usually stable. c) Modified recombinanls may be susceptible to certain rust strains. d) Revertants do not always possess the parental specificity.