<i>In vitro</i> induction and molecular and cellular identification of mutant plants of <i>Lilium leichtlinii</i> var. <i>Maximowiczii</i> (Regel) Baker by colchicine

<italic>Lilium leichtlinii</italic> var. <italic>Maximowiczii</italic> is a new type of edible lily with important nutritional and economic value. However, it is prone to lodging, and its bulb often follows the roots. To obtain better lily germplasms, different concentrations of colchicine were used to induce the growth of <italic>L. leichtlinii</italic> var. <italic>Maximowiczii</italic> seeds. The identification was conducted via plant morphology, chromosomal ploidy analysis, and ISSR molecular markers. The best induction effect was achieved by treating seeds with 0.15% colchicine for 48 h, with a seedling variation rate of 31.67%. After 17 months of cultivation, 11 mutant plants (Nos. 1−11) survived. The No. 2 plant grew rapidly and flowered earlier than the control plants. The No. 3 plant was significantly dwarfed, and its leaves became wider. Flow cytometry and root tip squash analysis revealed that the No. 3 plant was aneuploid, with 38 chromosomes in the root tip cells; the other plants were diploids, with 24 chromosomes. Microscopic observation revealed that the size of leaf epidermal cells and guard cells increased in the No. 3 plant, and the stomatal density significantly decreased, consistent with the characteristics of the polyploid plants. Additionally, ISSR marker analysis revealed significant differences in the No. 2 plant at the molecular genetic level compared with the control, with a variation rate of 18.99%. These results provide a reference for lily mutant breeding using the seeds by colchicine induction and the basis for further research on the early flowering mechanism in lily.