Ex situ conservation of Cycas debaoensis:a rare and endangered plant

Cycas debaoensis, an endemic species in China, is classified as a first grade national, key protected wild plant and was introduced to the Botanical Garden from Debao, Guangxi in 2002. This paper reports the ex situ conservation of C. debaoensis in Guilin. In the study area, leaf sprouting of mature plants happened from May to July, flowering occurred from May to June, and fruit maturity was from the middle 10 days to the last 10 days of November. Stem growth was slow with plant height averaging an increase of 1.90 cm a year, and ground-level diameter averaging an increased of 2.14 cm a year. Since C. debaoensis seed needed dormancy and could germinate after ripening, wet sand was the preferred storage method, having a seed germination rate of about 80%. Through several year's observation, C. debaoensis from calcareous soils in the southern subtropical zone could grow well, bloom, bear fruit, and have strong cold resistance in acidic soils. Ex situ conservation was successfully carried out in Guilin Botanical Garden.