Seed Germination And Dormancy Of Zygophyllum Xanthoxylon(Bunge)Maxim In Dabancheng

Zygophyllum xanthoxylon(Bunge)Maxim.,which grows in a habitat with strong wind and it is also an cadidativespecies in vegetation restoration.In this study,Fruits were buried in Dabancheng in August 2015,and exhumed at regular intervals and tasted their at 4 temperatures with fruits for burial seeds and aerial seeds.We also investigated the seedling emergence of Z.xanthoxylon in nature.The main results of the research are as follows:(1)Some seeds(39%)of Z.xanthoxylon had dormancy at maturity during dispersal.Seasonal change in temperature and water significantly influence on germination.After 6 weeks of buried(September 2015),germination percentage was increased.After 18 weeks of buried(December 2015),exhumed seeds had a high germination percentage at low temperature.Dormancy were broken during autumn and winter.After 42 weeks of burial(July 2016),seeds reenter into secondary dormancy in summer,and they change their temperature require and can't germinate at high temperatures(25/15??30/15?).After 54 weeks of burial(September 2016),second dormancy were broken in autumn,and germination was increased.After 70 weeks of burial(December 2016),seeds germination more than 97% during second winter,and > 93% of the seeds were viable.Seeds exposed on surface had a higher germination than those in soil at high temperatures.Burial seed of Z.xanthoxylon had a seasonal conditional dormancy/nondormancy cycle in Dabancheng.(2)Aerial seeds that storage on maternal plants canopy for 4,6 months still had a high germination percentage(>93%).And the germination percentage of aerial seeds were higher than that on soil surface.Seeds that storage on maternal plants canopy can help to maintaining seed viability.(3)The number of seedling emergence of Z.xanthoxylon in May,June,July,August,September,October were 0.02/m2,0.4/m2,2.9/m2,0.7/m2,5.8/m2,2.4/m2 respectively.The number of seedling emergence at autumn significant higher than others.The microhabitats of seedling emergence is cluster of Ephedra przewalskii,single individual of Z.xanthoxylon and bare low land.