GENETIC-POLYMORPHISM IN MARITIME PINE (PINUS-PINASTER AIT) ASSESSED BY 2-DIMENSIONAL GEL-ELECTROPHORESIS OF NEEDLE, BUD, AND POLLEN PROTEINS

Using two-dimensional polyacrylamide gel electrophoresis, the genetic variation of proteins was examined in three organs (needle, bud, and p ollen) from 18 trees of maritime pine. Three types of variation were n oted: presence/absence, staining intensity, and position variation of the spots. Of the 902 polypeptides scored in the three organs, 245 (27 .2%) were polymorphic. Moreover, among these variable spots, 117 were found in a single organ, demonstrating an increased polymorphism of th e organ-specific polypeptides (56.0% vs 18.4% for the organ-unspecific polypeptides). Finally, a positive correlation was found between vari ability level and subunit molecular weight for spots showing position variation but not for spots showing presence/absence or staining inten sity variations. Possible explanations for this observation are discus sed.