GENETIC-STUDIES OF SELF-FERTILITY IN RYE (SECALE-CEREALE L) .2. THE SEARCH FOR ISOZYME MARKER GENES LINKED TO SELF-INCOMPATIBILITY LOCI

The segregation of several isozyme marker genes has been studied in F2 inbred families from hybrids between self-sterile and five self-fertile inbred lines (nos. 2,3,4,5, and 8) as well as from interline hybrids. Self-pollination of F, hybrids between self-sterile forms and lines 5 and 8 gave an F2 segregation ratio of 1 heterozygote:1 homozygote for the gene Prx7 (chromosome IR) against the allele from the line. This is interpreted as a result of tight linkage of the Prx 7 gene with the S1 gene in chromosome 1 R (recombination at a level of 0-1%). The self-pollination of such hybrids with lines 2, 3 and 4 gave normal segregation for the Prx 7 gene (1:2:1). This means that these lines carry a self-fertility allele which is not on chromosome IR. Interline hybrids 5 x 2, 5 x 3 and 5 x 4 had self-fertility alleles for the two S genes and in inbred F2 progenies gave the expected deviating segregation for the Prx7 gene in a ratio of 2:3:1. The segregation of interline hybrid 5 x 8 was normal, 1:2:1, as expected. Highly-deviating segregation in an inbred F2 family of a hybrid with line 5 has also been obtained for another gene from chromosome 1R-Pgi2 (recombination with the S1 locus of 16.7%). By using the same method it has been estimated that line 4 has a self-fertility allele of the S2 locus from chromosome 2R and that the genes beta-Glu and Est4/11 are linked with it (recombination 16.7% and 17.5-20% respectively). Lines 2 and 3 have a self-fertility allele of the S5 locus from chromosome 5R which is linked with the Est5-7 gene complex (recombination at a level of 28.8-36.0%).