Date of Award

2002

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Horticulture

Advisor

Donglin Zhang

Second Committee Member

Willaim L. Mitchell

Third Committee Member

Jianhua Li

Abstract

Interest in growing native plants has been increasing in recent years. In an effort to better understand some valuable native plants for use in the Northeast, the propagation and taxonomy of several plants with potential as landscape plants were explored. In an effort to make more propagation information available to nursery growers and plant propagators, commercially feasible propagation methods were researched. Asarum canadense, Canadian wild ginger, seed is typically difficult to germinate; so warm stratification and gibberellic acid were tested to determine if this process would increase germination. Warm stratification mimics conditions to which the seed would typically be exposed in nature, and gibberellic acid is a plant hormone that can substitute for cold stratification and help increase gemination of seeds. After one, two, or three months in warm stratification; seed was soaked in gibberellic acid for 24 hours and placed in petri dishes. None of the seeds germinated, this could be the result of a double dormancy in the seed. Comptonia peregrina, sweet fern, is a native shrub often used in landscapes and erosion control. Because seed is difficult to germinate and stem cuttings are not successhl, root cuttings are the commonly used propagation method. Root cuttings were tested for their reaction to cold stratification length and temperature. The cuttings did respond to stratification length and temperature, with one month of cold stratification we achieved 100% rooting. In addition to rooting at higher percentages, cuttings treated with consistent temperatures of 3-4°C also rooted sooner, had more shoots per cell, and had longer shoots. , Two species of dogwood, Cornus alternifolia and C. rugosa, were tested for their reaction to different treatments of stem cuttings. C. alternifolia roots readily from softwood cuttings, but rooted cuttings have some difficulty overwintering. Extended photoperiods did not increase rooting percentages, suggesting that photoperiods do not effect rooting. C. rugosa is a relatively unknown in the nursery trade, so research was conducted to determine optimum propagation methods. Softwood cuttings were taken, but the leaves quickly turned brown and the cuttings died. Hardwood cuttings rooted at much higher percentages, with supplemental lighting actually being detrimental to rooting. Gaultheria procumbens, wintergreen, is a native woody plant with many potential uses in the landscape. Seed is typically hard to germinate, so seed was soaked for 24 hours in gibberellic acid to determine if germination percentages could be increased. Light conditions (ambient, extended, and dark) were also tested. Gibberellic acid did significantly increase percentages and ambient light conditions were found to be best for germination. Viburnum lantanoides and V. nudum var. cassinoides were tested for their reaction to treatments of softwood stem cuttings, rooting hormones, and extended photoperiods. K lantanoides rooted readily with 1000 ppm K-IBA treatment and light

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