Induction and identification of hexadecaploid of Pinellia ternate

Abstract

Pinellia ternate (Thunb.) Breit (Araceae) is an important Chinese medicinal herb. In order to obtain the hexadecaploid plants of P. ternate with improved medicinal qualities, the shoot tips from in vitro-grown plants were treated with colchicine at various concentrations for different time to double the chromosome number. We obtained highest (42.5%) frequency of morphological variation when the tips were treated with 0.1% colchicine for 48 h. The putative hexadecaploid plants showed characteristics such as larger and thicker leaves, deeper green leaf color, stouter petiole, larger stomata, lower density of stomata across the lower epidermis of leaves and increased numbers of chloroplasts per stomata guard cell. Further analysis by flow cytometry and chromosome counting confirmed seven out of 129 were hexadecaploids. Besides, the growth rate (GR) of PLBs in hexadecaploid plants was 10.49% (increase rate in 1 day), 1.6 times higher than that of octoploid plants and the alkaloid content of PLBs in hexadecaploid plants was 0.0794%, 1.8 times higher than that of octoploid plant. The results indicated that we have established a successful procedure for development and propagation of hexadecaploid of P. ternate with higher GR and alkaloid content.