Studies On The Germination And Emergence Characteristic Of Polygonatum Sibiricum Red., Polygonatum Cyrtonema Hua. And Polygonatum Kingianum Coll.et Hemsl. Seeds

Polygonatum sibiricum Red.,Polygonatum cyrtonema Hua.,and Polygonatum kingianum Coll.et Hemsl.are crude drug of the Chinese herbal medicine Polygonatum.In recent years,with the shortage of wild resources of Polygonatum,the aritificial planting areas of these plants have been gradually expanding but the cultivation is difficult because of long seed dormancy and very slow growth from seed.At present,there are few reports on Germination and emergence of P.cyrtonema and P.kingianum and the studies on seed of P.sibiricum.are mostly concentrated in the germination stage.In this work,begin with the basic characteristics of three kinds of seeds and base on Move-Along Experiment to find out the dormancy characteristics and dormancy period of three kinds of P.sibiricum seeds.Furthermore,determine their dormancy types and screen out temperature conditions during germination and emergence.In accordance with the requirement of seed inspection rule,the basic characteristics of three kinds of P.sibiricum seeds were determined including the thousand-grain weight,seed vigor and so on.The seed germination characteristics were explored by stratification at different temperatures(4,15,20,15?).Also,the seeds inhibition effect on germination of Chinese cabbage seeds was determined.The embryo differentiation and development of three kinds of P.sibiricum seeds were observed by paraffin section.The results show that:Without apparent differentiation of the embryo,hypocotyl,radicle,and cotyledon,their embryos were simple,the average embryo rate of P.sibiricum,P.cyrtonema and P.kingianum seeds were 56.39%,39.71%and 39.27%;their saturated water absorption were 36.81%,86.74%and 89.90%,in a certain soaking time;The viability of P.sibiricum,P.cyrtonema and P.kingianum seeds were 100%,96%and 96%respectively after six 6 months' storage.The germination frequency of the P.cyrtonema and P.kingianum seeds were 80.67%and54%respectively after they were stratification at temperature 25? for 90 days and began to emerge 120days later.After that,all the seeds emerged within 15-20 days.The seeds of P.sibiricum could germinate and form small bulbs at 15,20,25? but the germination time and rate were different at different temperature conditions;Seeds gone into dormant after the small bulbs had grown to a certain stage.The emergence rate was 93.33%after 60 days at 4?.There were different levels of germination inhibitors in seeds and small bulbs of P.sibiricum.The study concludes that:The P.cyrtonema and P.kingianum seeds dormancy belonged to the category of Morphological dormancy and P.sibiricum seeds dormancy belonged to the category of morphological and physiological dormancy which the embryos must go through two phases of morphological postripeness and physiological postripeness;Water absorption and embryo viability were not the main reason for the low germination rate of the three kinds of P.sibiricum seeds;The P.cyrtonema and P.kingianum seeds could germinate and emergence at 25? and P.sibiricum seeds could normally germinate at 25?,but there were some inhibitor in their epicotyl and needed a certain low temperature stratification to release seed dormancy before emergence.