Timothy K. Broschat and Henry Donselman
Charles R. Clement, Richard M. Manshardt, Joseph DeFrank, Catherine G. Cavaletto and Natalie Y. Nagai
María Luisa Osorio-Rosales and Martín Mata-Rosas
Experiments were conducted to establish an efficient protocol of micropropagation of Beaucarnea gracilis and B. recurvata two endemic and endangered Mexican species. Multiple shoots were induced by direct organogenesis from in vitro seedlings and longitudinal sections of seedlings in both species. The highest formation of shoots per explant, both B. gracilis and B. recurvata, was obtained from longitudinal sections of seedlings on Murashige and Skoog (MS) medium supplemented with 22.2 μm 6-benzylaminopurine, induced 8.2 and 11.1 shoots per explant respectively. In vitro rooting was readily achieved on MS medium with 1 g/l activated charcoal without growth regulators. According to initial treatment and depending on where the shoots come from, the rooting rates were 61% to 100% for B. gracilis, and 83% to 100% for B. recurvata. Survival rates in greenhouse conditions for both species were 80% to 100% after 3 months. These results indicate that the micropropagation of these species of Beaucarnea is technically feasible, and that in vitro culture is a useful option for the conservation and propagation of these important endangered species.
T.K. Broschat, D.R. Sandrock, M.L. Elliott and E.F. Gilman
nutritional deficiencies are palms ( Elliott et al., 2004 ). Because landscape ornamental plants are grown for their appearance, the presence of nutritional deficiency symptoms can reduce their aesthetic value, in addition to affecting plant health. Although
Sven E. Svenson and Timothy K. Broschat
The root distribution of seedlings of Acoelorrhaphe wrightii, Carpentaria acuminata, Chrysalidocarpus lutescens, Livistona chinensis, Phoenix roebellenii, and Washingtonia robusta were grown in nontreated containers or in containers treated on their interior surfaces with 25, 50 or 100 g CU(OH)2/1. Seedlings of all species grown in treated containers had reduced circling or matted roots at the container wall-growing medium interface. The distribution of root dry weight and root length was species specific, and was significantly influenced by the rate of copper hydroxide applied. Copper treatment did not induce visual signs of copper toxicity, nor differences in shoot growth, nor differences in the number of higher-order lateral roots.
Glenn C. Wright
HISTORY, EXPANSION, AND LOCATION OF THE DATE PALM INDUSTRY Palms are of the class Monocotyledonae order Arecales and family Aricaceae . Among the genus Phoenix , there are 13 species of palms, which are native from the Canary Islands east across
Karim H. Al-Juboory
The seeds of two cultivars of Phoenix dactylifera L. (Medjol and Deglet-Nour) were cultured on modified Murashige and Skoog (MS) medium containing 0.5 mg/l NAA and 2.0 mg/l BA. Later they were treated with 25 or 50 pulses of excimer laser radiation. The results indicate that these seeds exhibited significantly less contamination than control. The highest percentage germination for both cultivars was obtained with explants treated with 50 pulses excimer laser radiation. Compared to other treatments, the occurrence of somatic embryo-genesis and shoot regeneration was greater with the Medjol cultivar.
Erik S. Runkle, Royal D. Heins, Arthur C. Cameron and William H. Carlson
`Snowcap' Shasta daisy [Leucanthemum ×superbum Bergmans ex. J. Ingram (syn: Chrysanthemum ×superbum, C. maximum)] was grown under various photoperiods and temperatures to determine their effects on flowering. In the first experiment, plants were held for 0 or 15 weeks at 5 °C and then were grown at 20 °C under the following photoperiods: 10, 12, 13, 14, 16, or 24 hours of continuous light or 9 hours with a 4-hour night interruption (NI) in the middle of the dark period. Without cold treatment, no plants flowered under photoperiods ≤14 hours and 65% to 95% flowered under longer photoperiods or NI. After 15 weeks at 5 °C, all plants flowered under all photoperiods and developed three to four or 10 to 11 inflorescences under photoperiods ≤14 or ≥16 hours, respectively. To determine the duration of cold treatment required for flowering under short photoperiods, a second experiment was conducted in which plants were treated for 0, 3, 6, 9, 12, or 15 weeks at 5 °C, and then grown at 20 °C under 9-hour days without or with a 4-hour NI. Under 9-hour photoperiods, 0%, 80%, or 100% of plants flowered after 0, 3, or ≥6 weeks at 5 °C, and time to flower decreased from 103 to 57 days as the time at 5 °C increased from 3 to 12 weeks. Plants that were under NI and received ≥3 weeks of cold flowered in 45 to 55 days. For complete and rapid flowering with a high flower count, we recommend cold-treating `Snowcap' for at least 6 weeks, then providing photoperiods ≥16 hours or a 4-hour NI during forcing.
Timothy K. Broschat
required for the production of container-grown tropical ornamental plants. Materials and methods Expt. 1. Liners of areca palm and downy jasmine were transplanted into #2 (6.2-L) plastic containers filled with a 5 pine bark:4 Canadian peat:1 sand (by volume