GENETIC ANALYSES OF GLUTAMATE-DEHYDROGENASE ISOZYMES IN CULTIVATED AND WILD-SPECIES OF SECTION CEPA IN ALLIUM

Glutamate dehydrogenase (GDH) was studied to establish the genetic sys tem Of GDH isozymes in section Cepa of Allium. Detailed analyses of th e GDH zymograms of the diploid and triploid hybrids between A. fistulo sum and A. cepa Aggregatum group revealed that the degree of associati on of the GHD subunit varied from monomer to hexamer. The GDH expressi ons in the two cultivated and four wild species used in this study wer e governed by two alleles Gdh-1(F) and Gdh-1(A) at a single locus (Gdh -1). In A. fistulosum, A. galanthum, A. oschaninii and A. altaicum, th e allele Gdh-1(F) was observed, while Gdh-1(A) was noticed in A. cepa Aggregatum group, A. cepa Common onion group and A. vavilovii. These r esults indicate that the GDH isozyme genes are useful genetic markers in section Cepa.