Proliferation of Pyrus communis L. cv. Abate Fetel, Precoce Morettini, and Guyot was accomplished with a yield of 10 to 15 new shoots per explant. The in vitro procedure is based on the use of 6.7 μm BAP as an overlay on a modified MS medium. Rooting without callus formation was achieved by immersing the basal end in 5 μm IBA solution for 1 min. The possible inhibition of proliferation and plantlet regeneration by GA3 and IBA is discussed. Chemical names used: 6-benzylaminopurine (BAP); indole-3-butyric acid (IBA); gibberellic acid (GA3).
More than 400 genotypes of Prunus were evaluated for “in field” rooting and survival from fall-planted hardwood cuttings treated with 2000 ppm IBA. Cultivars of European and Japanese plums originating from species and interspecific hybrids of the section (sect.) Prunus had the highest survival. Cuttings from cultivars of sand cherry (sect. Microcerasus) and peach (sect. Euamygdalus) averaged 28% to 54% lower survival than European and Japanese plums. Few cultivars of almonds (sect. Euamygdalus), apricots (sect. Armeniaca), and American plums (sect. Prunocerasus) rooted from hardwood cuttings. Chemical name used: 1H-indole-3-butyric acid (IBA).
Mature flowering Arbutus texana trees were successfully micropropagated from shoot tips. Optimum shoot proliferation was achieved on a basal medium consisting of WPM salts, MS vitamins, and sucrose supplemented with 11.1 or 22.2 μm BA and no auxin. Microcuttings rooted readily when pulsed with 6.1 μm IBA for 1 week and transferred to auxin-free medium. The addition of charcoal to the rooting medium improved root branching and elongation but suppressed root formation. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); indole-3-butyric acid (IBA).
Leaf segments of greenhouse-grown Ulmus americana L. plants cultured on a Murashige and Skoog basal salts medium supplemented with 0.22 mg/L thidiazuron formed friable type of callus and regenerated shoots. This friable callus readily formed a cell suspension when the callus was placed in a liquid MS medium containing 2 mg/L 1-naphthaleneacetic acid and 1 mg/L 6-benzylaminopurine. Shoots were regenerated from 3-month-old suspension cell cultures after the suspension cells had been cultured on solid medium. Shoots developed roots on MS medium containing 0.1 mg/L indole-3-butyric acid. Intact plants were successfully established in soil.
The effect of bottom heat, wounding, and duration of stem basal IBA dip on macropropagation of Milicia excelsa was investigated. Bottom heat enhanced root dry mass and accelerated root initiation. Percentage rooting and root dry mass were not affected by wounding and duration of stem basal treatment. However, wounding interacted with bottom heat to affect dry mass (P < 0.05). Root biomass was 60% higher from wounded cuttings than from nonwounded cuttings under the nonheated condition. Chemical names used: 1H-indole-3-butyric acid (IBA).
The effects of stage of microspore development, cold pretreatment, and growth regulators on the embryogenic response of anthers from service tree (Sorbus domestica L.) are reported. Callus proliferation required the presence of growth regulators in the culture medium, best results being obtained with combinations of auxins and BA. Microspore embryogenesis was only induced when anthers containing tetrads or uninucleate pollen were cultured on BA-supplemented media containing IBA or IAA. A cold pretreatment before anther culture elicited a significant decrease in callus formation and inhibited embryogenesis. Chemical names used: benzyladenine (BA), indole-3-butyric acid (IBA), indole-3-acetic acid (IAA).
Friable embryogenic callus of American ginseng (Panax quinquefolium L.) was induced from root pith on Murashige and Skoog medium supplemented with 2 mg 2,4-D and 1 mg KIN/liter. Optimal callus growth occurred on medium containing 1.5 mg dicamba/liter. Plants were regenerated on MS medium supplemented with various concentrations of plant growth regulators (PGRs); the best PGR combination was 0.5 mg IBA and 0.1 mg NAA/liter. Chemical names used: (2,4-dichlorophenoxy) acetic acid (2,4-D); 3,6-dichloro-o-anisenic acid (dicamba); 6-benzylaminopurine (BA); gibberellic acid (GA); indole-3-butyric acid (IBA); kinetin (KIN); and naphthaleneacetic acid (NAA).
Ectomycorrhizal and nonmycorrhizal, glasshouse-grown northern red oak seedlings (Quercus rubra L.) received root treatments of IBA in starch, fired-montmorillonite clay, or starch-encapsulated montmorillonite clay. Clay proved to be superior to starch as a carrier for IBA, inducing significant increases in diameter, root length, leaf area, and shoot dry weight. Positive growth interactions between mycorrhizae and IBA were found with the clay carrier. The typical bare-rooted red oak seedling (grown for 1 year in nurseries and outplanted) performs poorly because of insufficient root size. Container-grown seedlings produced using clay/IBA treatments may perform better under field conditions than stock grown conventionally. Chemical name used: indole-3-butyric acid (IBA).
Abstract
The lack of satisfactory methods for clonal propagation of pecan [Carya illinoensis (Wangenh.) C. Koch] rootstocks resulted in the examination of mound stooling as a propagation technique. Semi-hardwood shoots from severed stumps received several treatments involving phloem girdling and IBA. Rooting occurred only in girdled or girdled plus IBA (3000 and 6000 ppm) treatments. Girdling triggered, whereas IBA enhanced, rooting. Roots per clone was related to shoot diameter but not height. Clones were able to survive harsh field conditions, thus providing a method for cloning rootstocks and facilitating rootstock research. Chemical name used: 1H-indole-3-butyric acid (IBA).
Abstract
Fall- and spring-planted spur ‘Delicious’ trees were monitored for first-year spur and shoot development and major carbohydrate levels in 1986 and 1987. Fall planting resulted in significantly greater shoot extension growth and lower tendency to become spurbound than spring planting during both years for two strains of spur ‘Delicious’. Higher starch reserves were found following the growing season after fall planting than after spring planting. A root dip of 10,000 mg a.i. IBA/liter before spring planting in 1987 did not affect any of the characteristics measured. Chemical name used: lH-indole-3-butyric acid (IBA).