INHERITANCE AND LINKAGE RELATIONSHIPS OF ISOENZYMES IN 2 INTERSPECIFIC CHERRY PROGENIES

Two interspecific cherry progenies, Prunus avium 'Napoleon' x P. incis a E621 and 'Napoleon' x P. nipponica F1292, were analysed with polyacr ylamide gel electrophoresis for 19 enzyme systems: alanine aminopeptid ase (AAP), aldolase (ALD), alkaline phosphatase (AKP), arginine aminop eptidase (ARA), catechol oxidase (CO), diaphorase (DIP), endopeptidase (ENP), esterase (EST), formate dehydrogenase (FDH), fructose-bisphosp hatase (FBP), beta-galactosidase (GAL), glucose-6-phosphate dehydrogen ase (G6PDH), beta-glucosidase (GLU), glutamate dehydrogenase (GDH), gl yceraldehyde-3-phosphate dehydrogenase (G3PDH), hexokinase (HEX), pero xidase (PRX), phosphorylase (PHO) and triose-phosphate isomerase (TPI) . Activity for GAL was identical with GLU, and CO with PRX. In additio n, activity for AKP was identical with some regions detected previousl y as acid phosphatase; and most of the PRX activity was identical with regions detected previously as superoxide dismutase. In all, 16 new s egregating loci were identified, Ara-1, Dia-2, Est-1, Est-2, -6, -7 an d -9, Glu-1 to -4, Hex-1, Pho-1 and -2, and Prx-8 and -9, together wit h 10 polymorphic putative loci. Analysis of cosegregations of the segr egating loci with each other, and with loci established previously, re sulted in 19 more loci being added to the cherry linkage map. Fifteen of these were new, and four had been described previously, but were hi therto unlinked. The additional linkages are: Ara-1- Dia-2-Mdh-2-Est-2 ; Glu-3/Prx-8-Glu-1/-2/-4-Prx-1/-9; Pgd-2-Pho-1/-2; Idh-2-Est-7-Est-6; (Amy-2)-Est-1-(Adh-4/-6); and (Acp-1/-2/-3)-Hex-1-(Gpi-2). (The brack eted loci had been mapped already). Several cherry linkages resemble l inkages reported in apple. Analysis of 14 cultivars of P. avium for th e same enzyme systems revealed polymorphism for just four of the 15 lo ci, and for an additional putative locus that was monomorphic in the i nterspecific material. This lack of isoenzyme polymorphism among cherr y cultivars reduces the utility of these markers for linkage analysis and mapping in progenies of P. avium.