Segregation and Linkage Relationships of Allozymes in Pinus Brutia Ten

Female gametophytes of Pinus brutia Ten. were analyzed to study Mendelian segregation and linkage among allozyme loci in a seed orchard composed of 28 clones. Isozyme variants of nine enzyme systems encoding 14 loci from megagametophytes were assayed by starch gel electrophoresis. While six of the 14 loci were monomorphic, the remaining eight were polymorphic. Analysis of observed segregation ratios of all polymorphic loci except for Sdh1, showed a good fit to the 1:1 ratios expected for Mendelian inheritance. Linkage relationships of the eight polymorphic allozyme loci were analyzed by testing 23 of the 28 possible two-locus combinations. Two-locus segregations in three pairs (Got2- Mdh1, Got2-Pgi2 and Pgd3-Sdh1) were significantly heterogeneous (P ≤ 0.05). Relatively weak linkage was observed between only one pair of genes (Adh2:Got2). Recombination fraction for Adh2:Got2 was found to be 0.24 (± 0.06).