exogenous auxin for the rooting of stem cuttings ( Ramos et al., 2003 ). The rooting method used for guarana seedling production suggests 70% shading, intermittent overhead mist, and the application of 2000 ppm indole-3-butyric acid (IBA); however, this
, and 100% for the 3, 8, or 30 mg·g −1 plants. Table 1. The response of Zamia furfuracea and Zamia integrifolia stem cuttings to indole-3-butyric acid concentrations of 0, 3, 8, 16, or 30 mg·g −1 . N = 25. The Z. integrifolia IBA study lasted 356
The percentage of rooting and survival of 1-year old non-juvenile pecan branches air-layered 50 days after bud break and left on the tree for about 5 1/2 months increased as indole-3-butyric acid (IBA) was increased from 0 to 3%. After 1 season’s growth, maximum survival occurred with air-layers that had been treated with 3% IBA. Shoot growth of the air-layers was relatively short.
Certain cultivars of magnolia are desirable in landscapes for their uncommon yellow flowers. While cultivars derived from Magnolia acuminata L. (cucumbertree magnolia) are difficult to propagate by stem cuttings, some with mixed parentage appear easier to propagate in this manner. We propagated six yellow-flowered cultivars vegetatively by applying 0, 8, 16, or 30 g·kg–1 (0, 8,000, 16,000, or 30,000 ppm) indole-3-butyric acid (IBA) in talc to bases of terminal stem cuttings collected 5, 7, 9, or 11 weeks after budbreak. Mean rooting percentage over all cultivars increased from 12% (in the absence of IBA) to 34% (after application of 30 g·kg–1 IBA). Rooting percentage and basal stem diameter of a cutting did not seem related. For each collection date, more cuttings of `Ivory Chalice' and `Yellow Lantern' developed roots than the other cultivars. More roots (mean = 5) developed on cuttings of `Yellow Lantern' collected 5 weeks after budbreak or when treated with 30 g·kg–1 IBA than the other cultivars. `Butterflies' largely remained unresponsive, whereas rooting of `Golden Sun,' `Hot Flash,' and `Maxine Merrill' collected 5 weeks after budbreak was 31%, 22%, and 28%, respectively. When data were analyzed separately for selected cultivars, 63% rooting was observed among cuttings of `Ivory Chalice' collected 7 weeks after budbreak. Rooting percentage was higher (22%) among cuttings of `Hot Flash' collected 5 or 7 weeks after budbreak in comparison to later collection dates, but harvest date did not influence rooting of `Yellow Lantern,' which ranged from 44% to 59%. Collection of stem cuttings early in the growing season (5 weeks after budbreak) was beneficial (31% rooting) for inducing rooting among cuttings of `Golden Sun.' We conclude that `Ivory Chalice' and `Yellow Lantern' are promising choices for growers interested in clonal propagation of yellow-flowered cultivars of magnolia. To maximize rooting among these cultivars, terminal cuttings should be collected within 5 to 11 weeks after budbreak and treated with 16 or 30 g·kg–1 IBA in talc. Early collection dates (5 to 7 weeks after budbreak) improved rooting among cuttings of other cultivars but these, particularly `Butterflies,' remain variably recalcitrant and merit further study.
lowest survival of litchi air-layering in control. The findings of Borah and Das (2000) are also in close conformity. Table 1. Effect of indole-3-butyric acid (IBA) concentrations on rooting percentage, number of roots, and fresh and dry weight of roots
, scale bar =1 cm; ( G ) plants acclimatized in a shady area (≈60% shade); ( H ) plants established in the field (≈2 years). WPM = woody plant medium; BA = 6-Benzylaminopurine; NAA = α-naphthaleneacetic acid; IBA = indole-3-butyric acid. The creamy white
treated with talc-based indole-3-butyric acid (IBA) at 0, 1000, 3000, or 8000 ppm. More of the cuttings of C. cornuta and V. acerifolium transplanted at 39 weeks, after a cold period, survived than did cuttings transplanted at 8 weeks after sticking
.59 + 0.064 (IBA), r 2 = 0.25, P < 0.05. Vertical lines = ± 1 se . IBA = indole-3-butyric acid. Regression analysis performed on ex vitro rooting data revealed no significant linear or quadratic trends. The highest concentration of K-IBA (41.4 μM
Micropropagation of Centaurea macrocephala Pushk. ex Willd. was achieved by subculturing of vertically split shoots and division of axillary buds on MS-based medium with 0.44 μm BA. A proliferation rate of 2.0 per 16-day culture period was obtained. Seventy percent of microcuttings obtained through in vitro culture could be rooted on a modified Hyponex medium with 25 μM IBA. All plantlets were readily acclimatized and grown in a greenhouse. Chemical names used: benzylaminopurine (BA); indole-3-butyric acid (IBA).
Shoots were regenerated from cotyledons of mature stored seed of three peach rootstock cultivars (`Flordaguard', `Nemared', and `Medaguard'). Shoot regeneration rates were highest when cotyledons were cultured for 3 weeks in darkness on Murashige and Skoog (MS) medium with 2.5% sucrose and a combination of IBA (1.25 or 2.5 μm) and TDZ (6.25 or 12.5 μm). Regeneration rates for `Flordaguard', `Nemared', and `Nemaguard' were as high as 60%, 33%, and 6%, respectively. Length of seed storage (1 to 3 years) did not affect regeneration rates. Seventy percent of regenerated shoots produced rooted plants. This regeneration method is rapid and simple, and stored seed can be used year-round. It may be a useful regeneration system for gene transfer in seed-propagated peach rootstocks. Chemical names used: 5 indole-3-butyric acid (IBA); thidiazuron (TDZ).