Date of Award:

5-2011

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Plants, Soils, and Climate

Committee Chair(s)

Roger K. Kjelgren

Committee

Roger K. Kjelgren

Committee

Steven R. Larson

Committee

Heidi A. Kratsch

Committee

Thomas A. Monaco

Committee

Paul G. Johnson

Abstract

Low-water landscaping (LWL) using native drought tolerant species is an essential tool for water conservation in the arid Intermountain West (IMW) for managing limited water supplies. However, many potential species have not been evaluated for LWL. Some species are difficult to visually distinguish from each other, thus decreasing confidence in products from native plant industry. Meanwhile, some species are difficult to establish to urban landscape conditions. The overall goal of this study is to elucidate morphological, ecophysiological, and genetic distinctions within two IMW native plant genera containing species with high urban low-water landscape potential.

For the first study, a classification model based on morphological characteristics of type specimens using canonical variate analysis (CVA) was successful in clarifying morphological variation among four Sphaeralcea species. Genetic variation among populations and species based on amplified fragment length polymorphisms (AFLPs) revealed two pure types among four putative species. Sphaeralcea munroana and S. parvifolia separated genetically from S. coccinea and S. grossulariifolia, and S. munroana appeared to be an ecotype of S. parvifolia.

In the second study, environmental conditions in selected six populations of Shepherdia rotundifolia varied among populations in terms of elevation, precipitation, temperature, relative light intensity (RLI), and soil properties. AFLP genetic varied between high and low elevation populations. Leaf area, specific leaf area (SLA), and leaf trichome structure exhibited adaptive traits to shady environments as well as hot and dry summer and cold winter environments in its native habitats. The SLA was significantly correlated with RLI, soil organic matter, and potassium.

In the third study, interspecific hybrid S. rotundifolia x argentea was intermediate morphologically and genetically to its parents. Leaf trichome structure and physiological responses of the hybrid were more similar to riparian S. argentea than S. rotundifolia, suggesting tolerance to regular watered urban landscape conditions.

Checksum

9a93fc56a9c3bf61eaa9d5ec9426f706

Comments

This work made publicly available electronically on September 29, 2011.

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