Isoenzymes of aspartate aminotransferase in perennial and annual rye and their hybrids.

Aspartate aminotransferase patterns were screened in a collection of rye genotypes that included 24 accessions of wild perennial rye (Secale montanum Guss.), 6 accessions of cultivated perennial Derzhavin and Tsitsin rye (Secale cereale x S. montanum), 15 accessions of winter and spring rye cultivars (S. cereale L.), and 9 accessions of perennial and annual rye genotypes bred from S. montanum ssp. kuprijanovii, Derzhavin rye, and winter rye for their resistance to fungal diseases. Aspartate aminotransferase is coded for by four loci. The data fit the model where AAT 1/4 is coded by Aat 1 and Aat 4, two duplicate loci, with null and two active alleles for each locus, alleles 1 and 3 for locus Aat 1 and alleles 2 and 4 for locus Aat 4; dimeric AAT 1/4 enzyme molecules are the products of both intralocus and interloci complementation. Allele 1 of Aat 1 was the most prominent in the isoenzyme patterns of the rye species. Alleles null and 2 of Aat 4 were twice as frequent in the perennial rye accessions, including Derzhavin and Tsitsin rye, than in winter and spring rye. In contrast, allele 4 of Aat 4 was characteristic of S. cereale. Within the screened collection, locus Aat 2 was monomorphic. Among three alleles of Aat 3, allele 2 dominated isoenzyme profiles of both rye species, whereas the other two alleles were species-specific: allele 1 was characteristic of S. montanum and allele 3 was found only in S. cereale. Key words : rye, Secale cereale, Secale derzhavinii, Secale montanum, aspartate aminotransferase, isoenzymes, perennial habit, polymorphism.