Drought response and potential resistance mechanisms of landscape roses /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1988.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Plants of 5 low-maintenance and 5 high-maintenance landscape rose (Rosa hybrida L.) cultivars were exposed to irrigation cycles which limited moisture availability for plant growth and development. Half of the plants in each low-maintenance cultivar were container grown in media amended with a hydrophilic gel. Ferdy and Pink Meidiland were the most drought resistant and White Meidiland was the least drought resistant of the low-maintenance cultivars, while Peace was the most and Double Delight and Paradise were the least drought resistant high-maintenance cultivars. Hydrophilic gel improved plant water relations; however, gel had little effect on growth parameters and reduced tissue nutrient content. The most drought resistant low-maintenance cultivars (Ferdy and Pink Meidiland), and least drought resistant high-maintenance cultivars (Double Delight and Paradise) were compared to determine potential physiological and morphological mechanisms which contribute to drought resistance. The low maintenance cultivars had lower osmotic potentials, slightly more epicuticular wax and cuticle by weight, and slightly smaller and less numerous stomata. All of these characteristics, along with limited growth and larger root to shoot ratios, may contribute to the improved plant water status of low-maintenance cultivars under limited moisture conditions. The effect of the mycorrhizal fungus, Glomus deserticola Trappe, Bloss & Menge on potential drought resistance mechanisms of Ferdy was evaluated on plants exposed to three water regimes. Water regimes included an acclimation treatment, in which plants underwent several preconditioning stress cycles prior to the measurement cycle, nonacclimated plants which received adequate moisture until the start of the stress measurement cycle, and nonstressed plants, which received adequate moisture throughout the study. Acclimated plants maintained a higher water status, as evidenced by higher transpiration, leaf water potential and relative water content under drought conditions compared to nonacclimated plants. The presence of the mycorrhizal fungus increased transpiration rates and decreased leaf water potentials within each water treatment; however, little effect on osmotic potential, epicuticular wax and cuticle thickness, or cell and stomatal characteristics was apparent. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Horticulture." |
| Physical Description: | xiii, 143 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references (leaves 122-131). |