susceptible trees giving an indication of genetic resistance ( Ramirez, 2005 ). If genetic resistance exists in natural populations, restoration of disease-free beech in North American forests may be possible through vegetative propagation of resistant trees
Marianela Ramirez, Marek J. Krasowski, and Judy A. Loo
Justin A. Schulze, Ryan N. Contreras, and Carolyn F. Scagel
( Huang et al., 2015 ; Kermani et al., 2003 ; Li et al., 1996 ; Ulrich and Ewald, 2014 ), we have found none that addressed adventitious rooting of stem cuttings. Successful vegetative propagation is an important consideration in determining plant
Nathalie Nivot, Alain Olivier, and Line Lapointe
Baskin, 1998 ; Luna, 2001 ). On the other hand, vegetative propagation could lead to mature individuals after a single year of cultivation. Several methods for the vegetative propagation of Trillium spp. have been described, all being based on the
Zhaohui Li, Yan Ma, Wanyuan Yin, Dekui Zang, and Xianfeng Guo
( Fu et al., 2001 ; Liu et al., 2011 ; Wei et al., 2007 ). Obviously, propagation by seeds leads to genetic variability and is not suitable for sustaining populations of the species or reproducing improved cultivars or strains. Therefore, vegetative
Keun H. Cho, Veronica Y. Laux, Nathan Wallace-Springer, David G. Clark, Kevin M. Folta, and Thomas A. Colquhoun
Vegetative cutting is an indispensable propagation technique for the mass production of ornamental annuals, perennials, herbs, shrubs, trees, and foliage plants. This method offers substantial advantages of maintaining identical phenotypic traits
Susan S. Han and Jennifer Nobel
The study was conducted to determine if ethylene or ethephon, an ethylene-releasing compound, can be used to induce abscission of phylloclades of four cultivars of Easter cactus [Rhipsalidopsis gaertneri (Regel) Moran] to increase efficiency in vegetative propagation. Abscission occurred within 24 hours after commencement of the ethylene treatments. Phytotoxicity, as exhibited by water soaking, transparency, and darkening of the phylloclades, as well as percent abscission, increased with increasing concentrations of ethephon (0 to 10,000 μl·liter–1). Ethylene released from ethephon, not the acidity of the solution, was determined to be the cause of the phytotoxicity. In three out of the four cultivars, vegetative and root growth from propagated phylloclades was significantly restricted by treatments with ethephon. In comparison, vegetative growth from phylloclades treated with ethylene at 20 μl·liter–1 was the same as from those treated with air. Root growth of the ethylene-treated phylloclades was not studied. The acidity of the ethephon solutions likely affected the growing regions, resulting in a reduction in growth. The study shows that treatment with ethylene gas or the use of pH-adjusted ethephon solutions may be an alternative to the labor-intensive procedures associated with vegetative propagation of Easter cactus. Chemical name used: 2-chloroethylphosphonic acid (ethephon).
Dale E. Kester and Ale E. Kester
148 POSTER SESSION 5E (Abstr. 292–296) Propagation–Fruits/Small Fruits/Nuts
Mariateresa Cardarelli, Youssef Rouphael, Francesco Saccardo, and Giuseppe Colla
A research project was conducted at the University of Tuscia, Viterbo (central Italy), to set up a vegetative propagation system for producing diseasefree artichoke transplants (Cynara cardunculus var. scolymus) of the Romanesco type (cultivar C3). The system included the following steps: 1) micropropagated plantlets were grown in a soilless culture year-round in greenhouse conditions, starting at the end of August; 2) stock plants were periodically treated with a chemical growth regulator [6-benzylamino purine (BA)] and then cut back at the collar level to promote offshoot production; 3) offshoots were periodically harvested and cold stored; and 4) cuttings were rooted at the end of spring under conditions of high humidity in multi-pack trays so as to be ready for summer transplanting. Results showed that the foliar application of BA to the stock plants increased the offshoot number quadratically to 200 mg·L-1. The rooting percentages of cuttings and root growth were enhanced by raising the cutting weight class (30-45 g) and by the application of naphthaleneacetic acid (NAA) to the cutting root zone at a rate of 2000 mg·L-1. The percent rotten cuttings increased as the 2 °C cold-storage time increased from 30 to 150 days. Similarly, the percentage of rooting and root growth decreased approximately from 60 to 150 days.
Paula M. Pijut and Melanie J. Moore
Juglans cinerea L. (butternut) is a hardwood species valued for its wood and edible nuts. Information on the vegetative propagation of this species is currently unavailable. Our objective was to determine the conditions necessary for successful stem-cutting propagation of butternut. In 1999 and 2000, 10 trees (each year) were randomly selected from a 5- and 6-year-old butternut plantation located in Rosemount, Minn. Hardwood stem cuttings were collected in March, April, and May. Softwood cuttings were collected in June and July. K-IBA at 0, 29, or 62 mm in water and IBA at 0, 34, or 74 mm in 70% ethanol were tested for root induction on cuttings. The basal end of cuttings were dipped in a treatment solution for 10 to 15 seconds, potted in a peat: perlite mixture, and placed in a mist bed for 5 to 8 weeks. Rooted cuttings were gradually hardened off from the mist bed, allowed to initiate new growth, over-wintered in a controlled cold-storage environment, and then outplanted to the field. For hardwood cuttings, rooting was greatest for those taken in mid-May (branches flushed out), 22% with 62 mm K-IBA and 28% with 74 mm IBA. Softwood cuttings rooted best when taken in June (current season's first flush of new growth or softwood growth 40 cm or greater) and treated with 62 mm K-IBA (77%) or 74 mm IBA (88%). For 1999, 31 out of 51 rooted softwood cuttings (60.8%) survived overwintering in cold storage and acclimatization to the field. For 2000, 173 out of 186 rooted softwood cuttings (93%) survived overwintering and acclimatization to the field. Chemical names used: indole-3-butyric acid-potassium salt (K-IBA); indole-3-butyric acid (IBA).
Xiao-Juan Wei, Xiao-Jing Liang, Jin-Lin Ma, Kai-Xiang Li, and Haiying Liang
collection, Camellia ‘Maozi’ has the potential to be developed as both a landscaping and a high-end indoor potted plant. However, as an interspecific hybrid, Camellia ‘Maozi’ is sterile. As a result, vegetative propagation is a major approach for the