[Seed germination characteristics and regeneration mechanism of Stellera chamaejasme population].
Stellera chamaejasme is a perennial herbaceous plant of Thymelaceae, as one of major poisonous plant species to animal, distributing in Northeast, Northwest, and Southeast of China. In some area on the degraded steppes, the plant grew with abnormal abundance and badly endangered the health of animals. The germination capacity of Stellera chamaejasme seed that collected from soil seed bank and immediately gathered from the plant was studied under different temperature, light condition and five pretreatments (rupture seed pericarp, remove seed pericarp, soaked in 98% H2SO4 for 5 min, soaked in 0.2% KNO3 for 24 h, and kept at 10 degrees C for a week). The seed germination percentage (GP) of the plant was lower in the mass and it was 13% under constant temperature 25 degrees C with dark condition. The suitable temperatures for germination of the seeds were constant 30 degrees C or alternative 10-30 degrees C. To rupture or to remove seed pericarp could significantly increase GP and it was 49% and 47%, respectively. GP under pretreatment of seed soaked in 98% H2SO4 for 5 min was 32%. The pretreatments of seed soaked in 0.2% KNO3 for 24 h and seed kept at 10 degrees C for a week had no significantly effects on increasing GP. The seed germination was not sensitive to light condition. The hardness of the seeds was mainly responsible for the seed dormancy and low germination rate. The GP of S. chamaejasme seeds in the soil seed bank was higher than that gathered in the immediate year. Based on the comprehensive analysis with the lower GP and the results of field observation, it was concluded that S. chamaejasme seeds did not germinate every year in nature, and chance of population regeneration was random or periodic.
Key Laboratory for Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China. xingf@nenu.edu.cn
Fu
F
Xing
Jixun
J
Guo
Yanhong
Y
Wang
D018525:Germination; D008027:Light; D012038:Regeneration; D012639:Seeds / Q000254:growth & development*; D013696:Temperature; D029645:Thymelaeaceae / Q000254:growth & development*