Biosystematics of the genusPopulusL. II. Chemotaxonomy, phenology, fertility, and segregates of native Manitoba species and variants

摘要

Chemotaxonomical, phenological, fertility, and hybrid segregation characteristics have further elucidated the relationships ofPopulusspecies and variants in southern Manitoba.Species chromatograms, made with bark collections from widely separated localities, were consistently uniform and proved reliable for species identification. Chromatograms of variant individuals were unlike those of any species examined. Flowering and seed shedding inP. balsamiferaL.,P. deltoidesMarsh. var.occidentalisRydb., and variants occurred together and about 2 weeks and 4 weeks later than respective dates forP. tremuloidesMichx.Hybrid fertility, measured by seed set was lower than the expected values for fully fertile hybrids ofP. balsamiferaandP. deltoidesvar.occidentalis. All variant populations, except from Grand Beach, produced greater than 90 vigorous seedlings. Seedling progenies from several apparent F1hybrids segregated towardsP. balsamiferaandP. deltoidesvar.occidentalis. No segregates similar to or approachingP. tremuloideswere recovered.