Colchicine-induced chromosome doubling in Platanus acerifolia and its effect on plant morphology

Abstract

We report the production of tetraploid plants of Platanus acerifolia, with the ultimate aim of improving the ornamental qualities of this important urban landscaping tree. Chromosome doubling was achieved by the application of colchicine to either pre-soaked seed or to the apical meristems of young seedlings. Treatment of the ungerminated seed was the more eYcient method in terms of numbers of tetraploid seedlings (up to 40%, as determined by chromosome counting of the root-tip nuclei) but this method produced no mature tetraploid plants due to the deleterious eVect of colchicine on subsequent root growth. When colchicine was applied directly to the apical growing tip of cotyledon-stage seedlings, leaf and stem growth was temporarily aVected but the plants eventually recovered. We conducted a preliminary screen for putative tetraploids based on the observation in other plant species of a correlation of stomatal size and distribution with ploidy. Plants containing signiWcantly larger stomata and at a lower density across the lower leaf epidermis, were selected for further analysis by Xow cytometry and chromosome counting. These techniques conWrmed that, of the 12 putative polyploids, four were tetraploid, Wve were mixoploid and three were, in fact, diploid. Morphological diVerences of the tetraploids included a more compact growth habit and broader, thicker leaves. These plants are being grown to full maturity in order to test their potential for use in a breeding programme aimed at producing sterile triploid lines.

Polyploidy Induction of Moth Orchid (Phalaenopsis amabilis (L.) Blume) by Colchicine Treatment on Pollinated Flowers

“…Nakasone (1960) reported that treatment of Vanda and Dendrobium seeds with colchicine of 1000 up to 10000 mg L -1 for more than four days caused interference on their germination. Similar results were also reported in non-orchid plants, in Cyclamen seeds by Takamura and Miyajima (1996) and Platanus acerifolia seeds by Liu et al, (2007). …”

Introgression of yellow flower colour in Buddleja davidii by means of polyploidisation and interspecific hybridisation

“…Eeckhaut (2003) also only regenerated chromosome doubled plants when B. davidii seeds were treated with oryzalin and trifluralin. This concurs with results in other genera, such as Platanus, where treatment of (ungerminated) diploid seeds with colchicine was the most efficient method to obtain tetraploid seedlings (Liu et al 2007). The use of nodal sections has some advantages over the treatment of seed(lings); only one selected genotype is treated when using nodal sec- tions.…”

Induction of tetraploid hardy rubber tree, <i>Eucommia ulmoides</i>, and phenotypic differences from diploid

“…For Acacia crassicarpa (Fabaceae), the effective concentration was 0.001-0.020% (Harbard et al 2012). For plants in the genera of Paulownia (Scrophulariaceae) and Platanus (Platanaceae), it was 0.05% and 0.4%, respectively (Liu et al 2007;Tang et al 2010). The score of treatment conditions for E. ulmoides was within the range of these woody plants; its sensitivity to colchicine might lie about halfway within the scores of treatment conditions reported for other woody plants.…”