Seed dormancy and germination of three herbaceous perennial desert ephemerals from the Junggar Basin, China

The purpose of our study was to better understand seed germination ecology of the spring ephemeral herbaceous perennials, Ixiolirion tataricum, Tulipa iliensis and Scorzonera pusilla, in the temperate desert in the Junggar Basin of northwestern China. Seeds of I. tataricum, T. iliensis and S. pusilla were dormant at maturity but when subjected to cold, dry (2 months at 48C) followed by cold, wet (#40 days at 48C) conditions, they germinated to 100%, 96% and 93%, respectively. After 2 months’ dry storage at 48C, seeds germinated to only 11%, 3% and 42%, respectively at 158C, and no seeds germinated at 308C. Seeds of the three species were not sensitive to light. Low (,12.7%) and high (21.4%) soil moisture contents suppressed germination. In addition, both final germination percentages and rates of the three species decreased dramatically with a decrease in water potential from 0 to 23.17 MPa. Thus, the low-temperature requirement for dormancy break and germination cues seed germination to occur in early spring when soil moisture is favourable for germination and subsequent seedling establishment.