Micropropagated grapes (Vitis sp. `Valiant') were subjected to water stress while rooting with the addition of 2% (w/v) PEG 8000. PEG-treated plantlets exhibited reduced growth, as compared to control (in vitro, no PEG), but developed greater leaf epicuticular wax. PEG-treated plantlets had three times the wax level of control. Although treated plantlets showed changes in leaf anatomy, no effect on stomatal frequency or stomatal index was evident. Differences in epidermal cell configuration were also observed among leaves from different treatments. PEG-treated plantlets resembled those grown in the greenhouse, morphologically and anatomically, and exhibited a higher survival rate than control upon transfer to the greenhouse.
Imed Dami and Harrison Hughes
The morphological development of lingonberry (Vaccinium vitis-idaea L.) plants propagated either by conventional softwood cuttings or by in vitro shoot proliferation from nodal explants or by shoot regeneration from excised leaves of micropropagated shoots, was studied in cultivars `Regal', `Splendor', and `Erntedank'. Significant differences were observed between the treatments. In vitro-derived plants produced more shoots branches and rhizomes in contrast to conventional cuttings which rarely produced rhizomes. Plants propagated from cuttings had a lower number but vigorous shoots and thicker rhizomes than in vitro-derived plants. Source propagule had significant effect on multiplication rate. Another experiment evaluated the effect of indole-3-butyric acid (IBA) application to softwood cuttings on subsequent rooting, shoot development, and rhizome production. Treating cuttings with IBA did not significantly improve rhizome formation and elongation. In vitro culture on nutrient medium apparently induces the juvenile branching characteristics that favored rhizome production. The advantage of rhizome production of in vitro-derived plants over stem cuttings varied among genotypes.
Samir C. Debnath
The growth and development of lingonberry (Vaccinium vitis-idaea L.) plants propagated either by conventional softwood cuttings or by in vitro shoot proliferation from nodal explants and by shoot regeneration from excised leaves of micropropagated shoots, were studied in cultivars `Regal', `Splendor', and `Erntedank'. Significant differences were observed between the treatments. After 3 years of growth, the in vitro-derived plants produced more stems, leaves, and rhizomes than the conventional cuttings which rarely produced rhizomes. In vitro culture on nutrient medium apparently induces the juvenile branching characteristics that favor rhizome production. This increase in vegetative growth and rhizome yield of in vitro-derived plants over stem cuttings varied among genotypes.
M.A. Norton and R.M. Skirvin
Chimeral `Thornless Evergreen' (CTE), (Rubus laciniatus Willd.) somaclones selected in 1983 and field planted in 1985 were reexamined in 1992 for various vegetative and reproductive characteristics. Two major types of thornless (prickle-free) plants, intermediate-sized (`UI 6-6' = `Everthornless') and dwarf (`UI 6-4'), originally selected from a chimeral thornless parent plant, were compared with thorny plants. The intermediate and dwarf somaclones have maintained their distinctive habits over 7 years' growth in the field, indicating that their growth habits are stable and not a transient effect of tissue culture. Although the thornless somaclones remained thornless, the degree and type of prickle-like structures varies considerably, indicating that the thornless gene (S te) does not entirely suppress the production of prickles, but apparently alters their development. Increasing suppression was directly related to increasing dwarfism, suggesting a link between thornlessness and internode length.
Lawrence W. Zettler, Sarah B. Poulter, Kris I. McDonald, and Scott L. Stewart
of transplanted seedlings ex vitro ( Anderson, 1991 ; Ramsay and Dixon, 2003 ), and it is conceivable that the same could be true for epiphytes. Moreover, the act of releasing mycotrophic seedlings in situ could also result in the release of suitable
Jin Cui, Juanxu Liu, Min Deng, Jianjun Chen, and Richard J. Henny
ex Fr.) has become the most common disease of arrowhead vine. This opportunistic airborne fungal pathogen particularly occurs during the ex vitro rooting of microcuttings after shoot culture because the cutting base is especially susceptible to this
Dongliang Qiu, Xiangying Wei, Shufang Fan, Dawei Jian, and Jianjun Chen
shoot organogenesis. Microcuttings derived from adventitious shoots of a cultivar were evaluated for both in vitro and ex vitro rooting. Results suggest that the developed protocols could be used for micropropagation, genetic transformation or both of
Seong Min Woo and Hazel Y. Wetzstein
acclimatized over 4 weeks. Two months after transplanting, plants were transferred to the greenhouse. Additional studies were conducted to evaluate ex vitro rooting. Shoots 2 to 4 cm long were harvested from cultures in shoot elongation medium. The base of 48
Todd J. Rounsaville, Darren H. Touchell, Thomas G. Ranney, and Frank A. Blazich
Mahonia have been successfully achieved both in vitro and ex vitro using a variety of auxins. Mackay et al. (1996) achieved nearly 100% rooting of M. trifoliata in vitro using 1.0 μM naphthaleneacetic acid on cultures younger than 6 months. However
Michael W. Bairu, Manoj G. Kulkarni, Renée A. Street, Rofhiwa B. Mulaudzi, and Johannes Van Staden
abnormal. Statistical analysis. Ex vitro results were analyzed using MINITAB® release 14 statistical package (Minitab Inc., State College, PA). One-way analysis of variance was conducted to test Fisher's significance level at 5%. Percentage germination data