Lobularia maritima (L.) Desv. is an important ornamental plant. HortScience investigated an efficient method to induce tetraploid plants of L. maritima (L.) Desv. by treating germinating seeds and apical growing points of seedlings with a range of concentrations of colchicine for different periods of time. Examination of the ploidy level by counting chromosome numbers at metaphase confirmed that the chromosome number of diploid plants was 2n = 2x = 24, whereas 2n = 4x = 48 was observed in tetraploid plants.
The morphological characteristics of the diploid and colchicine-induced tetraploid plants were compared. Increases in the size of leaves, flowers, and stomata were observed in the tetraploid plants compared with the diploids. However, the stomatal density and plant height of the tetraploid plants were lower than for the diploid plants. This study presents the first report of autotetraploid plants of L. maritima (L.) Desv., and of the successful generation of tetraploid plants with improved ornamental traits by colchicine treatment.
