Genetic Variability in a Provenance Collection of Fraxinus pennsylvanica, Marsh

Green ash (Fraxinus pennsylvanica, March.) is a deciduous tree native to a large area of the Great Plains Region of the United States.It is widely planted in shelterbelts, farmstead windbreaks and ornamental plantings throughout the plains region. The purpose of this study is to obtain additional information concerning genetic variability, to provide the basis for selection of specific genotypes, and to build a foundation for a breeding program. Green ash seed from individual trees in native stands from seven states of the Great Plains Region was collected and planted in a nursery bed at Lincoln, Nebraska in 1970.These seedlings were transplanted to field plantations at three Nebraska locations (Hastings, Lincoln, and Plattsmouth) in 1971.Seedling height growth was recorded along with phenological observations in the spring and fall. Southern seedling sources grew faster and for a longer duration in the fall than did northern sources.The time of seed germination greatly influenced total height growth the first season to minimize this difference. Although variation in growth rate existed among seedlings within a stand, the variation in growth rate among geographic areas of the region was more pronounced.Variation appeared to be clinal in nature. Progeny from a Minnesota geographic area grew considerably faster than other progeny of the same latitude.Green ash seed collected from Minnesota might provide good growing seedlings for Nebraska. Advisor: Walter T. Bagle