Sporophytic and gametophytic gene expression in <i>Populus deltoides</i> Marsh., <i>P</i>. <i>nigra L</i>., and <i>P</i>. <i>maximowiczii</i> Henry

Abstract

Male gametophyte (pollen) isozyme profiles of P. deltoides, P. nigra and their hybrids, and of P. maximowiczii were compared with those of the sporophyte (roots). Fifteen enzyme systems were resolved by starch gel electrophoresis for each species and hybrid, and a total of 51 encoding genes were observed. In P. deltoides, P. nigra, P. deltoides × P. nigra, and P. maximowiczii, respectively, 74, 80, 74, and 76% of the structural genes coding for these enzymes in the sporophyte were also found to be expressed by the male gametophyte. Most of the genes tested were found to be expressed after meiosis, apparently transcribed and translated in the haploid genome.Key words: gene expression, gametophyte, sporophyte, Populus, isozymes.