Search Results
You are looking at 21 - 29 of 29 items for
- Author or Editor: R. Daniel Lineberger x
The effects of woody plant medium (WPM) with various formulations and concentrations of Cu+2 on in vitro rooting and subsequent shoot growth of microcuttings of a Betu pubescens × papyrzfera (birch) clone were monitored for 28 days. Adventitious root initiation and elongation were reduced in magnitude and slowed in development by moderate to high Cu (as CuSO4·5H2O) concentrations, with near zero root regeneration occurring at 157 μm Cu. Shoot growth was also inhibited by 157 μM Cu as cupric sulfate. Copper-toxicity symptoms (senescent leaves, necrotic stems, and bulbous and stunted roots) were significantly increased by moderate to high levels (≥ 79 μm) of Cu as cupric sulfate. Microcuttings responded differently to Cu+2 applied as cupric chloride (CuCl2·2H2O). Root initiation, root elongation, and root branching were increased by moderate concentrations of Cu as cupric chloride. Shoot growth was slightly stimulated by cupric chloride at moderate levels. No significant increase in Cu-toxicity symptoms was observed at concentrations up to 157 μm Cu as cupric chloride. Cupric acetate [Cu(CH3 COO);H2O] and cupric carbonate [CuCO3·Cu(OH)2] produced more severe Cu-toxicity symptoms than cupric sulfate. Root regeneration and shoot growth were inhibited and increased Cu-toxicity symptoms were apparent even with low concentrations (39 μm) of Cu as cupric acetate or cupric carbonate. There was little or no effect on root regeneration when the Cu+2 in cupric sulfate was replaced by different cations, i.e., magnesium sulfate (MgSO4·7H2O), calcium sulfate (CaSO4·2H2O), and sulfuric acid (H2SO4), a result suggesting that the observed responses could be attributed to the Cu+2 concentration. Changes in media pH did not correspond to Cu-toxicity symptoms or alterations in root or shoot growth by the Cu compounds.
Aggie Horticulture (http://aggie-horticulture.tamu.edu) is the information server of the Texas horticulture program. Contents include information of interest to Texas A&M students and faculty, faculty members at other universities, extension programs at the state and county level, members of the horticultural industries, and the consuming public. Aggie Horticulture is a registered server on the World Wide Web that can be accessed by any networked computer on the Internet that is running “browser” software such as Mosaic or Netscape. Modem access is gained using Internet connections provided through PPP or SLIP connections. Web browsers will change dramatically the way extension provides information to horticultural industries and the consuming public. Techniques for organizing a server and the challenges associated with maintaining a server for world access are discussed.
Three spineless phenotypes of Acacia wrightii G. Bentham ex A. Gray were identified with aesthetic landscape potential. Experiments in seed, cutting, grafting, and tissue culture propagation were undertaken to perpetuate this desired spineless phenotype. Germination percentages for mechanically scarified seeds ranged from 33% to 94%, however yield of spineless seedlings was low (0% to 34%). Sulfuric acid scarification for 10, 20, 30, or 60 minutes hastened and unified germination compared to nontreated seeds by 7 to 8 days. Vegetative propagation was successful for softwood cuttings. Rooting measures increased with auxin (2:1 indole butyric acid to naphthalene acetic acid) concentrations from 0 to 15000 mg·L–1, with maximum rooting percentage (70%), root number (9.2), and root length (12.4 cm) per softwood cutting at 15000 mg·L–1 auxin 8 weeks after treatment. Rooting was not successful for semi-hardwood or hardwood cuttings. Whip-and-tongue or T-bud grafting was not successful. Tissue culture of shoots from in vitro germinated seedlings indicated that shoot proliferation was greatest in Murashige and Skoog (MS) medium with 15 μm zeatin. The number of shoots that rooted in vitro increased with increasing concentrations of indole-3-butyric acid from 0 to 25 μm.
Fifteen genetically diverse roses were evaluated for the ability to undergo somatic embryogenesis. Over the two media (MS and B5), two sugars (glucose and sucrose), and two explants (filaments and petiole) used, 20 to 30% of the `Tournament of Roses' callus was embryogenic whereas only crystalline callus was produced in cultures of `Baby Love', `Ingrid Bergman', `Perfume Delight', `Prominent', `Sunflare', and 90-202. Cultures of `Tournament of Roses' consistently produced somatic embryos whereas `Baby Love' produced no embryos. An F1 progeny of `Tournament of Roses' × `Baby Love' was chosen to test whether the ability to undergo embryogenesis in Rosa hybrida L. is heritable. Data collected from tests on F1 progeny between these genotypes suggest that the ability to undergo embryogenesis is indeed heritable in an additive fashion.
The purpose of this study was to determine the effect of the presence of live interior plants or window views of exterior green spaces on employee job satisfaction. A survey was administered through an online database. The survey included questions regarding physical work environment, the presence or absence of live interior plants, windows, exterior green spaces, environmental preferences, job satisfaction, and demographical information. About 600 office workers from Texas and the Midwest responded to the on-line workplace environment survey. Data were analyzed to compare levels of job satisfaction of employees that worked in office spaces that included live interior plants or window views of exterior green spaces and employees that worked in office environments without live plants or window views. Demographic information collected allowed controlling for salary, occupational level, educational level, age group, gender, and ethnicity. This research data can be particularly useful in urban planning, commercial property design and to encourage the incorporation of plants and green spaces in interior and exterior development projects.
A comprehensive survey of American and Canadian universities that offer masters, doctoral, or both degrees in horticulture resulted in responses from 27 academic units. Units were surveyed regarding types of degrees offered, admissions policies, demographic characteristics of students, financial assistance provided to students, faculty ranks and salaries, and metrics by which the programs were evaluated by university administration. About 80% of the programs resided in 1862 Morrill Act land-grant institutions (LG) with the remainder housed in other non-land-grant institutions (NLG). Thirty-eight percent of reporting LG programs existed as stand-alone horticulture departments, whereas horticulture programs were combined with other disciplines in the remainder. Admissions criteria were most consistent among LG programs. Participation in distance education programs was low, but growing. Financial support of graduate students was more common in LG programs. Most schools offered some sort of tuition reduction to those students on assistantships/fellowships and offered health insurance options. Payment of fees was rare and the level of stipends provided varied substantially among programs. International student enrollment was greatest at LG programs and had remained steady in recent years. Gender equity was present among graduate students, with nearly equal male and female enrollment. Most graduate students at both LG (63.6%) and NLG (75.0%) programs were non-Hispanic White; although overall minority enrollment had increased but was still not similar in distribution to that of the general U.S. population. Professors (46.7%) and Associate Professors (28.3%) dominated the faculty ranks while Assistant Professors (19.3%) and lecturers/instructors (5.7%) constituted a much smaller portion of the faculty. Faculty salaries varied tremendously among institutions, especially for senior faculty. Female and ethnic minorities were underrepresented in faculty ranks compared with the general U.S. population. Aside from total graduate program enrollment, the relative importance of various evaluation metrics for programs was highly variable among institutions. Data discussed herein should be useful to universities with horticulture graduate programs for peer institution comparisons during program assessments, accreditation reviews, or for strategic planning purposes.
The Coordinated Educational and Marketing Assistance Program identifies outstanding landscape plants for Texas and provides support for the nursery industry, thereby making superior plants available to Texans. CEMAP funding comes directly from industry and from consumers through the sale of plant tags bearing the Texas Superstar logo. Additionally, the Texas Nursery and Landscape Association and Texas Department of Agriculture is conducting a Texas Superstar publicity campaign. An estimated $10 million in new plant sales have been generated during the first 10 years of this program. Because plants are chosen based on their performance under minimal input conditions, Texas SuperStars greatly reduce their impact on the urban environment.
Plant trialing and marketing assistance programs have become popular in recent years with several state and some regional programs emerging. Successful implementation requires considerable labor, facilities, and monetary resources for evaluation of large numbers of taxa over several years to ensure that plants are well adapted to the region of interest. Research and development funds, dedicated facilities, and cooperator commitment to trialing programs can be limiting during the early years of the programs. Involvement in plant trialing programs allows students to be exposed to plot layout planning, statistical design, plant maintenance, data collection and analysis, and professional communication of trial results. Construction of facilities for conducting plant trials, growing plants for use in trials, trial installation, and maintenance of plants all provide practical hands-on horticultural training. Replicated plant trials provide the latest information on regionally adapted taxa for inclusion in classroom instruction and publications. Plant trialing programs benefit from labor assistance, development of dedicated facilities, and the opportunity to share equipment and supplies among teaching, trialing, and student research projects.