herbicides such as oryzalin may be preferable for inducing polyploidy. The objective of the current study was to induce polyploidy in Cryptomeria japonica using oryzalin. Materials and Methods Plant material. Wild-collected seed from China of
Ryan N. Contreras, John M. Ruter, and Brian M. Schwartz
Daniel C. Milbocker
Pyrus calleryana, Decne, `Aristocrat'; Cryptomeria japonica, D. Don; Populus maximowiczii, Henry × `Androscoggin' and Koelreuteria bipinnata, Franch. trees were grown in low-profile containers. The optimum height and width of these containers was 20 to 30 cm and 84 cm, respectively. Pine bark and mixtures containing 50% or more of pine bark were preferable to mixtures containing leaf mold for filling the containers because the former weigh less. Roots penetrated pine bark mixtures better than sphagnum peat mixtures and also retained their shape better during transplanting. When grown in low-profile containers, trees grew fibrous root systems; after transplanting, roots grew downwardly radial and trees were able to withstand extremely difficult landscape conditions.
Laura G. Jull, Stuart L. Warren, and Frank A. Blazich
Stem cuttings of `Yoshino' Japanese cedar [Cryptomeria japonica (L.f.) D. Don `Yoshino'], consisting of tips (terminal 20 cm) of first-order laterals, distal halves (terminal 10 cm) of tips of first-order laterals, and proximal halves (basal 10 cm) of tips of first-order laterals, or tips (terminal 10 cm) of second-order laterals, were taken on four dates that represented four growth stages (softwood, semi-hardwood, hardwood, and pre-budbreak). The cuttings were treated with 0, 3000, 6000, or 9000 mg IBA/liter. Branch order affected all rooting measurements at each growth stage. Regardless of growth stage, tips of and proximal halves of first-order laterals containing lignified wood had the highest percent rooting, root count, total root length, root area, and root dry weight. Hardwood tips of and semi-hardwood proximal halves of first-order laterals exhibited the highest overall rooting (87%), followed by softwood proximal halves of first-order laterals (78%). Rooting of distal halves of first-order laterals and tips of second-order laterals never exceeded 55% and 34%, respectively, at any growth stage. IBA treatment influenced percent rooting, root count, total root length, root area, and root dry weight of semi-hardwood, hardwood, and pre-budbreak cuttings, except for root dry weight of semi-hardwood cuttings. IBA had no affect on softwood cuttings. Chemical name used: 1H-indole-3-butyric acid (IBA).
Ryan N. Contreras
.N. Ruter, J.M. Schwartz, B.M. 2010 Oryzalin-induced tetraploidy in Cryptomeria japonica (Cupressaceae) HortScience 45 316 319 Dirr, M.A. 2009 Manual of woody landscape plants: Their identification, ornamental characteristics, culture, propagation and uses
Robert J. Rouse, Paul R. Fantz, and Ted E. Bilderback
Japanese cedar [Cryptomeria japonica (Thun. ex L.f.) D. Don. (Taxodiaceae)] cultivars have become quite popular in the U.S. landscape and nursery industries. Their popularity is expected to increase as more attractive and adaptable horticultural selections gain recognition. Taxonomic problems include an inadequate inventory of selected variants cultivated in the United States, instability of names at the infraspecific taxonomic level, poor descriptions of the cultivars, and a lack of representative specimens and identification aids to help horticulturists identify unknown specimens. A study of Cryptomeria japonica cultivated in the United States is needed to address these problems.
Robert J. Rouse, Paul R. Fantz, and Ted E. Bilderback
Japanese cedar, Cryptomeria japonica (Thunb. ex L.f.) D. Don [Cupressaceae Bartling, formerly assigned to Taxodiaceae Warm.] is increasing in popularity as a landscape plant in the eastern United States. A taxonomic study of cultivars grown in the eastern United States was conducted. Forty-five cultivars were recognized. Each cultivar bears synonymy, a quantitative morphological description newly described from field data, herbarium vouchers, references to original literature and observational notes. A glossary of taxonomic terms relevant to Cryptomeria is presented. A taxonomic key is presented for segregation of cultivars that should assist professional plantsmen in identification of taxa cultivated in the eastern United States.
Ryan N. Contreras, Ron Determann, and Mara Friddle
Japanese-cedars ( Cryptomeria japonica D. Don) are large trees in their native range of Japan and China and are often used as timber trees that may reach 36 to 46 m high in the wild ( Dallimore and Jackson, 1967 ). In managed landscapes they are
Ryan N. Contreras, John M. Ruter, James S. Owen Jr., and Andy Hoegh
Japanese-cedar [ Cryptomeria japonica (L.f.) D. Don] is a variable conifer that grows up to 60 m tall in its native range. Wild-type specimens are conical when young and become cylindrical with age ( Eckenwalder, 2009 ). Japanese
Zhiyong Hu, Min Zhang, Qigen Wen, Jie Wei, Hualin Yi, Xiuxin Deng, and Xianghua Xu
allotetraploid somatic hybrids and speculated that these phenomena resulted in the production of sterile pollens. Moreover, Hosoo et al. (2005) proposed that monads of Cryptomeria japonica (L. f.) D. Don was incited by nuclear fusion or defects in chromosome
Xiaojuan Wei, Siyu Wu, Xiaojing Liang, Kun Wang, Yuejuan Li, Baocai Li, Jinlin Ma, and Haiying Liang
. Without intervention, seeds are not produced until the trees are 25 to 30 years old ( Kuser, 1982 ). Male strobili of Cryptomeria japonica were induced by GA 3 sprayed onto the shoots ( Kurita et al., 2020 ). Therefore, the effects of hormones on sexual