A Preliminary Study on Dormancy and Germination Physiology of Endangered Species Berchemiella wilsonii (Schneid.) Nakai var.pubipetiolata H.Qian Seeds

Berchemiella wilsonii (Schneid.) Nakai var.pubipetiolata H.Qian,an endangered plant,is endemic to China and the national third-class protected plant.Seed vigor,tested by TTC,is very low(32%),however,empty seeds and seeds without vigor amount to 28% and 40%,respectively,demonstrating that there is a limitation in seed development of B.wilsonii (Schneid.) Nakai var.pubipetiolata H.Qian.The poor water permeability of seed coat,testified by water absorption experiment,hinders water absorption during seed germination.In every part of the seed exists germination inhibitors,the most in seed embryo,which restrain seed germination and induce seed dormancy of B.wilsonii var.pubipetiolata.Seed germination rate and germination index are improved after soaked by different GA₃ concentrations for 24 hours before germination.The effect of 300 mg/L GA₃ is the most significant and it can also markedly increase the activity of catalsae,peroxidase and dehydrogenase during the early 3 days after germination.Sees germination rate of B.wilsonii var.pubipetiolat is rather low because of the presence of seed dormancy and low seed vigor,as well as poor activity of the several enzymes concerned with germination capacity,and these are also considered as the main factors to cause B.wilsonii var.pubipetiolat endangerment in the aspect of germination physiology.