Production of Tetraploid Plants of Trollius chinensis Bunge Induced by Colchicine

Trollius chinensis Bunge is one of the important ornamental and medicinal plants cultivated in China. In this study, the tetraploid plants of Trollius chinensis were successfully induced by colchicine and their morphological, cytological and fertility characteristics were investigated. The results indicated that the tetraploid species of Trollius chinensis (2n = 4x = 32) was efficiently induced from the diploid species (2n = 2x = 16) by colchicine under 0.05% to 0.2% concentrations, with the best induction under treatment combinations of 0.1%, 24h duration and 0.2%, 12h duration. In comparison with the diploid plants, the tetraploid plants exhibited dramatically varied phenotypic features, showing increased leaf length and width, petiole, flower and pollen diameters. In addition, they also exhibited increased stomatal size and chloroplast numbers in guard cells. Tetraploidy reduced the pollen fertility. Nevertheless, the maintenance of female fertility makes the tetraploid a potential germplasm for further polyploid breeding. Our investigation provides a potential design for an effective pathway to generate varieties of this plant species with chromosome doubling.