Effects of various pre-treatments on dormancy-break and seed germination of Saussurea veitchiana (Asteraceae), an endemic medicinal herb of southwest China

Abstract

Subalpine Saussurea veitchiana (Asteraceae) is useful for the treatment of various diseases and is vulnerable to extinction. Methods to break seed dormancy and enhance germination of this species, as well as the response of seeds to different temperatures, were investigated. Freshly harvested seeds germinated to very low percentages at ten temperature regimes in light conditions. Gibberellic acid (10 - 200 μM) partially broke the dormancy of fresh seeds, and the highest germination was 54% when seeds were treated with 200 μM GA3 and incubated at 20°C or 25/15°C. Cold stratification significantly increased germination over that of the control (i. e., seeds dry stored at room temperature, approximately 18°C). Seeds cold stratified at 4°C for 60 or 90 days germinated to 83 and 87%, respectively, at 25/15°C and had a MGT of 7.11 and 6.37 days, respectively. Taken together, the seeds of S. veitchiana have non-deep physiological dormancy, and cold stratification for 60 days or longer is recommended as a practical dormancy-breaking treatment for propagation of this species from seeds.