Biosystematics of the genus Populus L. II. Chemotaxonomy, phenology, fertility, and segregates of native Manitoba species and variants

Abstract

Chemotaxonomical, phenological, fertility, and hybrid segregation characteristics have further elucidated the relationships of Populus species 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 in P. balsamifera L., P. deltoides Marsh. var. occidentalis Rydb., and variants occurred together and about 2 weeks and 4 weeks later than respective dates for P. tremuloides Michx.Hybrid fertility, measured by seed set was lower than the expected values for fully fertile hybrids of P. balsamifera and P. deltoides var. occidentalis. All variant populations, except from Grand Beach, produced greater than 90% vigorous seedlings. Seedling progenies from several apparent F1 hybrids segregated towards P. balsamifera and P. deltoides var. occidentalis. No segregates similar to or approaching P. tremuloides were recovered.