( 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
Justin A. Schulze, Ryan N. Contreras and Carolyn F. Scagel
Marianela Ramirez, Marek J. Krasowski and Judy A. Loo
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
Andrew R. King, Michael A. Arnold, Douglas F. Welsh and W. Todd Watson
; Pezeshki and DeLaune, 1994 ). Grafting is a reliable but more expensive method of propagating baldcypress ( Dirr, 2009 ; Thomsen, 1978 ). Alternatively, vegetative propagation by cuttings yields uniform plants and through selection can be used to expedite
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
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
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
The term “clone” is a key biological term that designates a number of horticultural situations. In breeding, many cultivars are designated as clones, originating from consecutive vegetative propagation from individuals within a seedling population, from individual plants of a clone exhibiting “bud mutations,” and, more recently, from genetic engineering and biotechnology. Extensive vegetative propagation of a limited numbers of clones in modern horticultural systems has been accompanied by systemic incorporation by serious pathogens (viruses, viroids, phytoplasmas, etc.), and in some cases by horticultural deterioration (e.g., noninfectious bud-failure in almonds). Control of these problems in clonal propagation is achieved by 1) propagation source selection 2) maintenance of the source in a registered foundation block under protected conditions and 3)multipli-cation in controlled “mother blocks” or “increase blocks” from which commercial material is distributed after a minimum of consecutive generations of vegetative propagation. This system is the basis for Registration and Certification programs and “clean stock” in general. In many crops the selected propagation source is a single plant, its progeny constitutes a “clone,” and the new entity is given a unique name or number. To distinguish this “new” clone from the “original” clone, the designation of FOUNDATION CLONE is suggested. Biological and horticultural significance is illustrated in almond (Prunus dulcis).
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).
Chieri Kubota, Ayami Yamaguchi and Toyoki Kozai
For vegetative propagation of sweetpotato, single or multi-node leafy cuttings are used as propagules. A quantitative understanding of leaf development and the effects of environment conditions on leaf emergence and expansion rates is important for predicting the number of propagules produced after a given production period. Single-node cuttings each with a fully expanded leaf were grown under two levels of photosynthetic photon flux (PPF, 160 and 250 μmol·m–2·s–1) and photoperiod (10 and 16 h/day). The time courses of the number of leaves larger than the standard leaf area (As) were obtained by analyzing the time courses of leaf blade length recorded every day on each leaf. The number of leaves larger than a given As increased almost linearly after the first leaf reached to the As. PPF and photoperiod affected both the duration until the appearance of the first leaf with As and the leaf development rates (leaves per day). The effects of PPF were more pronounced than photoperiod for the development rate of the leaves regardless of As. Results obtained in these experiments were incorporated into our previously developed model, and the number of propagules produced under different environment conditions was predicted. Such techniques need to be used effectively for planning and environment control of vegetative propagation.
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.