Native plants are often ignored in horticulture because they may lack major ornamental traits and many of them are difficult to propagate. Creamy indigo (Baptisia bracteata Mnhl.) is a North American legume with considerable potential as a container-grown or ornamental plant for managed landscapes. Nodal explants from aseptically germinated seedlings were evaluated for axilary shoot and leaf development. The explants were cultured on Murashige and Skoog medium (MS) containing adenine sulfate at 80 mg•L-1, 30% sucrose, and different levels of N-6-benzyladenine (BA) (0.5,1.0,2.0 mg•L-1) supplemented with indole-3-acetic acid (IAA) (0.05, 0.1 or 0.5 mg•L-1) or with IAA omitted. Shoot regeneration occurred within 2 to 3 weeks. The best medium for shoot regeneration was MS supplemented with BA at 1.0 mg and IAA at 0.1 mg•L-1. Shoots were transferred onto rooting medium consisting of Ω MS supplemented with 1.0 mg alpha-naphthaleneacetic acid (NAA) and 1.0 mg indole-3-butyric acid (IBA)/L and 20% sucrose. Rooting took place within 3 to 5 weeks. Plantlets were then planted in soil mix, placed under a polyethylene tent for 2 weeks, and transferred into the greenhouse for further growth.
Hristina H. Stamenova-Berberova and Paul E. Read
Breeding, selection and evaluation of woody landscape plants has been an active project at the Univ. of Minnesota for many years. The goal of the project is to develop and or identify superior plants that are well adapted to the climatic conditions of Minnesota and other northern areas. About 20 cultivars of many species have been introduced to the nursery trade through this program in the past 20 years. These introductions result from selections made from populations arising from controlled crosses and from open-pollinated populations and native plant populations. One of the primary efforts has been development of the cold hardy, “lights series” of deciduous azaleas. These possess flower bud hardiness of from –35 to –40 °C. Other current breeding activities include efforts with Viburnum, Acer rubrum, Rosa, and intergeneric hybridization in the Pomoidaea subfamily of Rosaceae. An integral part of the project is development and use of techniques to screen for tolerances to various environmental stresses. Approaches used will be discussed and plants currently under evaluation will be described and illustrated with slides.
Kathleen M. Kelley, Janine R. Stumpf, James C. Sellmer, and Ricky M. Bates
Consumers were surveyed at the 2004 Philadelphia Flower Show in Philadelphia, Pa. from 8–10 Mar., to quantify their attitudes and behaviors towards invasive plant species and the potential problems associated with purchasing and planting invasives in the landscape. A majority of the 341 participants (81.5%) was aware that non-native exotic plants were used in the landscape and that these plants may be invasive in natural areas. Less than half (40.1%) acknowledged owning plants that were considered invasive, while one-third (33.5%) did not know. Less than half (41.3%) believed that laws should be passed to prevent sale of non-native exotic plants, while 27.8% believed that laws should be passed to allow sale of only native plants in their area. Three distinct consumer segments were identified using cluster analysis: “Invasive savvy,” participants knowledgeable about invasives and interested in alternative species; “Invasive neutral,” participants neutral in their decision to purchasing alternatives to invasive plants and price sensitive in regard to paying more for plants tested for invasiveness; and “Invasive inactive,” participants opposed to purchasing genetically modified plants or those bred to be seedless. Survey results indicated that media sources (e.g., television and newspapers/magazines/books) would be effective for educating consumers about potential problems associated with invasive species in the landscape.
Tina M. Waliczek, Paula S. Williamson, and Florence M. Oxley
The purpose of this study was to determine college students’ understanding of invasive species and their support for plant and animal pest control and eradication methods. Surveys were administered at a university and community college in Texas in biology and agriculture departments. A total of 533 respondents participated in the study. Most students said they were not part of any type of environmental organization and felt they were not very informed about invasive species issues. More students reported learning about invasive species in high school than in college courses. The average score on knowledge questions related to invasive and native plants and animals was 32%. Most students underestimated the negative impact of invasive species but many were aware of costs to manage those species. Reliable reported sources of information included environmental organizations, college courses, and the Internet. Pearson product-moment correlations showed positive relationships between students who had college class instruction regarding invasive species and positive attitudes toward management of invasive species. Positive relationships were also found between instruction and an awareness of invasive plants or animals. Respondents who were knowledgeable of invasive species in the community had more positive attitudes toward the management of invasive species. In demographic comparisons, differences were found with males, upperclassmen, and those identifying as Caucasian or other having more knowledge of invasive species and more positive attitudes toward their management.
Julia L. Bohnen and Anne M. Hanchek
Production of native seeds and seedlings for landscaping and restoration is an expanding horticultural industry in Minnesota, but seed yields of many species from wild stands are often small and vary widely in quality. In this work, we document phenological development and seed yield in cultivated and prairie-grown plants for Tradescantia ohiensis Raf. (Ohio spiderwort), Dalea purpurea Vent. (purple prairie clover), and Spartina pectinata Link (prairie cordgrass) at the Minnesota Landscape Arboretum. For T. ohiensis, seed yield under cultivation was significantly greater than in the prairie both seasons, with 2.5 g of seed recovered per plant in 1993. Under cultivation, seed yield of established D. purpurea was triple that of the prairie, yielding 34 seeds per inflorescence. S. pectinata grown under cultivation from seedlings or rhizome divisions produced seed in the first and second seasons, respectively, while plants in the prairie remained vegetative. Two-year-old seedlings produced 38 seeds per spike. Field cultivation of these native plant species resulted in increased seed yield and improved growth, while allowing phenological monitoring and the use of species-specific harvest practices.
Pamela J. Bennett, Ellen M. Bauske, Alison Stoven O’Connor, Jean Reeder, Carol Busch, Heidi A. Kratsch, Elizabeth Leger, Angela O’Callaghan, Peter J. Nitzsche, and Jim Downer
of Cooperative Extension at the University of Nevada, Reno, is helping to bridge this gap and enrich teaching, extension, and EMG programs. At the University of Nevada, Reno, EMGs grow five species of native plants for the Natural Resource and
Benjamin J. Glover, Tina M. Waliczek, and Jean-Marc Gandonou
-conscious living, or for generating a profit marketing a new crop ( Starling, 2007 ). Native plants have been marketed in the horticultural industry for landscape use, but little marketing research has emphasized the use of native plants as a food source. Those
Angela O'Callaghan*, Florence Brown, Denise McConnell, and Robert Morris
Southern Nevada Master Gardeners (MGs) donate 50 hours annually to educational and service projects. These volunteers respond to community needs by developing and staffing horticultural projects under UNCE supervision. In Las Vegas, 20 such projects exist. Some are more energy and information intensive than others. Mojave Guides are docents at the Desert Demonstration Garden, a part of the Las Vegas Springs Preserve, not Extension. They commit to a shift at the garden, providing information to visitors. While they are directly supervised by garden staff, the hours they contribute are Master Gardener hours. These volunteers receive training in desert flora from gardens staff and participate in seminars on selected topics. The MG Orchard Team operates a teaching orchard at the Center for Urban Water Conservation in North Las Vegas. These volunteers maintain hundreds of fruit trees and grape vines. They receive training on topics related to fruit trees and orchard management. This project began in 1996. Since 2002, they have been formalizing their organization using the logic model and SWOT analysis. Many members work weekly at the orchard and take the produce to a local farmers market. This raises funds for the orchard and is an opportunity to teach the community about desert horticulture. Project PLANT volunteers work at the Red Rock National Recreation Area visitor center and grounds. They are docents who also learn about and maintain the native plants there, and prevent infestations of invasive weeds which threaten the area. Their monthly meetings include training on topics related to the project. These projects are successful because of the MGs themselves. They grew out of interest and continue because the volunteers have drawn commitment from others.
Mary Hockenberry Meyer*
Miscanthus sinensis was investigated where it has naturalized and invaded native plant communities in southeastern Pennsylvania, the Washington, D.C. area, western North Carolina, and Iowa. Plants were identified; inflorescences were collected; seed was cleaned and tested for viability; and soil was collected for seed bank analysis. Many individuals were interviewed at each location. Locations were mapped to show miscanthus. The species or “wild type” Miscanthus sinensis that has naturalized at the above locations is rarely sold in the nursery trade. The numerous, popular, ornamental cultivars derived from this species are vegetatively propagated clones that are common in the nursery trade. Miscanthus is self-incompatible and sets seed only when two or more genotypes are grown together. Individual isolated plants set little seed. Plants of the wild type which have naturalized each represent a unique individual or genotype and thus set heavy seed, quite different from ornamental cultivars. Further complicating this is the high variability of seed set due to environmental conditions. Management guidelines were developed along with recommendations which include: Do not plant the species Miscanthus sinensis. Cultivars of the species, especially when two are more are grown together, represent a high risk for self-seeding in the Mid Atlantic states. Cultivars should only be planted in areas where they can be watched and managed for self-seeding. No miscanthus should be planted where it can seed into native areas, such as highways, fields, meadows, or wooded areas. A comprehensive website with identification, pictures, management guidelines, and recommendations was developed: http://horticulture.coafes.umn.edu/miscanthus.
Zhen Zhang and Zong-Ming Cheng
Jasmonates are a group of native plant bioregulators that occur widely in the plant kingdom and exert various physiological activities when applied exogenously to plants. We investigated the effect of free jasmonic acid (JA) on stem and root growth and tuberization of potato in vitro nodal culture. Nodal cuttings of three potato cultivars, Norchip, Red Pontiac, and Russet Burbank, were cultured in 2.5 × 15 cm test tubes containing either nodal culture (MS with 2% sucrose) or tuber-inducing (MS with 8% sucrose and 11.5 μm kinetin) medium. The media were supplemented with JA at 0, 0.1, 0.5 1.0, 5.0, 10.0 and 50 m. The cultures were maintained under a 16-hour photoperiod at 24°C for 6 weeks. Potato cultivars showed different sensitivities to JA in stem growth. Norchip is the most and Red Pontiac the least sensitive cultivar. On the nodal culture medium, stem length of Norchip was promoted at 0.1–5 μm, and inhibited at 10–50 μm of JA, but that of Red Pontiac was promoted by JA at all concentrations tested. The number of nodes increased significantly on media with JA than that on medium without JA. The number of adventitious roots did not, but the lateral roots increased significantly when JA was added to the medium. On tuber-inducing media, stem length and node number did not appear to be affected by addition of JA to the medium. The number of axillary shoots increased significantly on the media with low concentrations of JA (0.1–5 μm). No microtubers formed on both media from all three cultivars in 6 weeks.