Genetic interpretation of malate dehydrogenase (MDH) isozyme gene loci using a new staining approach and the genetic control of ten other isozymes in Pinus roxburghii SARG.

Genetic control of malate dehydrogenase and ten other enzymes have been investigated in Pinus roxburghii, the most extensively distributed pine of India. Seeds were collected from eight natural populations covering about one third of the species' distribution range. In total, 2560 samples consisting of equal number of embryos and endosperms were analysed for AGO, AAT, CDH, IDH, LAP, MDH, MNR, PGI, PGM, 6PGDH and SKDH using starch gel electrophoresis. Eighteen polymorphic loci were found to code for these enzymes. Two to three alleles per locus were identified. Mostly the isozyme loci followed the expected 1:1 segregation ratio. MDH was stained with two staining methods to distinguish between different isozyme gene loci. Three loci proved to be variable. Intra-locus as well as inter-locus heterodimeric hybrid bands were identified, the latter giving evidence for the existence of a gene duplication.