GENETICS OF CYTOSOLIC PHOSPHOGLUCOSE ISOMERASE (PGI) VARIATION IN THEAMAZONIAN TREE PSEUDOBOMBAX-MUNGUBA (BOMBACACEAE)

A genetic analysis of cytosolic phosphoglucose isomerase (PGI) variati on in the tropical tree Pseudobombax munguba (Bombacaceae) was carried out in one population from Central Amazon. It was shown that cytosoli c PGI variation is controlled by two diallelic loci (Pgi-2 and Pgi-3). All nine possible enzyme phenotypes produced bl, allelic variation at these two loci were easily identified on gels stained for PGI. Progen y analysis from cross-pollinated families revealed that the two loci a ssorted independently and exhibited disomic inheritance, suggesting th at allopolyploidy may have been the cause of the duplication of the cy tosolic PGI gene in this species.