Genetic polymorphism of isozymes in loblolly pine seed

A study was made of three enzymes, leucine aminopeptidase, alcohol dehydrogenase, and peroxidase in dry loblolly pine (Pinus taeda L.) seed. Two 10 tree modified half diallels in two separate wild strands were used as seed sources. Crude seed extract was electrophoresed in starch gel for three and one half hours, the gel was sliced into three slices and specific histochemical strains were applied to each separate slice for each enzyme. One variant was found in alcohol dehydrogenase. Instead of the normal six band pattern usually found, the number 5 band split into three bands giving an eight band pattern in the variant. The variant was observed only when the tree was the female parent and was not observed when reciprocal crosses using the tree as a male parent were analyzed. In peroxidase enzymes, two anodal bands were analyzed. Cathodal bands were observed but not recorded and analyzed. The two anodal bands appear to be controlled by two genes which produce dimmers. In starch gel, the hybrid middle band expected from random association of dimeric subunits was only observed occasionally, but when acrylamide was used the hybrid middle band was observed regularly. About 20% of the crosses analyzed had much wider bands than the average cross. When these crosses were run on disc acrylamide gels, a multiple banding pattern was observed in the wide staining area. In this area, six bands were observed which could have formed by random association of dimeric subunits. This banding pattern could result from a mutation in the gene responsible for dimeric subunit production. Starch gel electrophoresis of leucine aminopeptidase enzymes did not produce resolution clear enough to detect isozyme variants with the procedures used. A six band isozyme pattern was observed in leucine aminopeptidase