树苜蓿在甘肃的育苗试验

Breeding Trial of Chamaecytisus palmensis in Gansu Province

Chamaecytisus palmensis is an evergreen legume shrub. It was introduced to China in 2002 for the first time from Australia and since then many studies, including forced germination treatments, germination test, direct sowing, container seedling and cutting seedling propagations, over-winter response, have been conducted in three districts (Dingxi, Tianshui and Wudu) of Gansu province in 2002—2005. The results showed that germination of C. palmensis took very long probably because the seeds had lipidic coat and a 63% of the seeds had hard cost, and its 1 000-seed mass was 23^92 g. The six forced germination treatments were applied, and the effects of sodium carbonate and detergent treatments were moderate, however safe and practical among them. The viablility of all treated seeds were 82%, and the germination rate was 94^5% in lab. The field germination test showed that the seeds imbibing to coat rupture had the fastest germination speed, the seed imbibing without coat rupture had moderate germination speed and poorer germination rate, whereas the seeds without any treatment had slower germination speed and best germination rate. The average germination rate and survival rate were 91^1% and 82^1% of three types of seed. The suitable soil mulching depth was 2～3 cm. The cutting propagation had a higher callus produce rate of average 60^0% and lower rooting rate of average 20^5%. And the rooting rate of ABT treated cutting was higher than that of control plant, 10-hour treatment with ABT was better than 2-hour treatment, upper and middle section of shoot was better than lower section. %Chamaecytisus% palmensis is a shade-intolerant and fast-growing species, and its one-year old seedlings had an average over 1 m height and about 1 cm basal diameter, about one and a half years old seedling had an average over 2 m height, 3 cm basal diameter. The one year old seedling grew better in Dingxi district than in Wudu, whereas over 1-year-old seedling grew better in Wudu district either. The one year old seedlings were able naturally live through winter in Wudu but not in Dingxi and Tianshui mainly because of the differences in their climate factors. The results suggested that %C. palmensis% could be cultivated in the area of 33°24′ latitude and the southern area of Longnan, Gansu. However, it is very difficult to cultivate the species at large scale in Longnan area because the seedlings need to be protected for surviving over the harsh winter.