INHERITANCE AND LINKAGE RELATIONSHIPS OF ISOZYME VARIANTS OF PINUS-LEUCODERMIS ANT

Inheritance and linkage relationships of 13 enzyme systems were investigated by horizontal starch gel electrophoresis in female gametophytes of Pinus leucodermis ANT.. Isozymes observed were under the control of at least 23 loci. In 2 of these loci, GDH and NDH, no variation was detected. The segregation of allozymes in megagametophytes of heterozygous trees revealed simple Mendelian inheritance for most of the enzyme systems analyzed. Distorted segregation ratios were observed at ACO, GOT and LAP loci. Linkages were studied by analyzing 61 2-locus combinations. Significant linkage, as attested by the 95% confidence intervals, was detected for GOT-A:PGI-B, G6PD-A:LAP-B, LAP-B:PGM-A and 6PGD-B:PGI-B. Estimates of recombination frequencies varied trees. The tightest association was observed between 6PGD-B and PGI-B loci, with a recombination frequency of 8.1%.