Effects of temperature, scarification, dry storage, stratification, phytohormone and light on dormancy-breaking and germination of Cotinus coggygria var. cinerea (Anacardiaceae) seeds.

摘要

Identifying the type of seed dormancy of a species is an essential prerequisite for subsequent studies on its seeds. Previous studies suggested that there is combinational (physiological and physical) dormancy in Cotinus coggygria var. cinerea seeds, but the level and the type of physiological and physical dormancy are not still known. In the present study we investigated the effects of temperature, scarification, dry storage, stratification, phytohormone and light on dormancy-breaking and germination of C. coggygria var. cinerea seeds. The present study showed that excised embryos produce normal seedlings. Both dry storage and GA₃ were helpful in both dormancy-breaking and germination of scarified seeds. Neither 6-BA nor ethephon promoted germination of fresh scarified seeds. With increasing stratification time at 5 degrees C, seeds germinated over a wider temperature range. Light inhibited germination of scarified seeds, but cold moist stratification and ethephon treatment could partially offset the inhibitory effects of light on breaking physiological dormancy of scarified seeds. These results indicate that C. coggygria var. cinerea seeds possess Type 3, non-deep physiological dormancy. We hypothesize that physical dormancy can also include a few levels which result from different developmental state of the seed coat or endocarp.