Study On Cryopriservation Of Lauraceae Etc. Seeds Mechanism And Technology

The study on cryopreservation mechanism of recalcitrant seeds germplasm of tree species has very important theoretics and practic sense ,it can improve the seeds vigor and prolong the span of seeds conservation, which of six species were study on this article .such as Cinnamomum cassia,Cinnamomum caphora(L.),Litseacubeba,Machilus oreophila,Manglietia yuyuanensis Law.This study dealt with cryopreservation mchanism based on analysis of various rules of physiology and biochemistry characteristic, including dehydrogenase , a -amylase activity ,relative conductivity, MDA and proline content .Meanwhile the optimal technique of cryopreservation, including optimal moisture content (MC), freezing technique, thawing technique and pre-treatment technique of cryoprotectants,were drew out to serve for forest production. The results showed as follows.1.After cryopreservation, the dehydrogenase and a -amylase activity of 20% moisture content Cinnamomum cassia embroy was the highest by fast-freezing-quick-thawing method and the relatively conductivity was the lowest. MDA content was very low by mild-freezing-quick-thawing method ;Desiccation-tolerance of exised embryo 20% moisture content was well induced and its proline content accumulated more than any one of other.The vigor are maintained better than other treatment by using method of mild-freezing-quick-thawing.the relative conductivity was lowest by mild-freezing-quick-thawing method. With pre-treatment of cryoprotectants solution, optimal moisture content of exised embryo enhanced to 25%moisture content level, and the conservation effectiveness was better than that of no adding cryoprotectants treatment,which depended on the type and concentration of cryoprotectants.2.A11 the physiology and biochemistry characteristic index show that 15%moisture content Cinnamomum caphora embroy was adapt to cryopreservation by fast-freezing-quick-thawing mothod. With pre-treatment of cryoprotectants solution,the result was more better than with none.3.The dehydrogenased and a-amylase activity of 10% moisture content embroy were the highest and MDA content was the lowest by fast-freezing-quick-thawing method. Tts proline content was the highest by mild-freezing-quick-thawing method.With the cryoprotectants the optimal conservation was 15% moisture content and mild freezing mild thawing treament.4.The optimal treament of machilus oreophila emproy were combination of 10% moisture content and fast-freezing-quick-thawing,which dehydrogenase and a-amylase activity were all high .Relative conductivity and MDA were low and membrane repair ability of embroy is strong with fast-freezing-quick-thawing ,meanwhile the proline content was the lowest of 15% moisture content. With pre-treatment of cryoprotectants solution and mild-freezing-quick-thawing,optimalMC of ecised embryo enhanced to 15% moisture content level,which effectness is better than that of none.5.The optimal treatment of Sassafras tsumu embroy is 15% moisture content using mild-freezing-mild-thawing,the dehydrogenase activity was the highest and MDA content was the lowest.The relative conductivity is the lowest, After using the cryoprotectants and mild-freezing-mild-thawing the effectness is the best.6.Manglietia yuynanensis seed of 15% moisture content through fast-freezing-quick-thawing treatment.The dehydrogenase activity of 10% moisture content embroy with mild-freezing-quick-thawing, while the a-amylase activity and the proline content were the highest with fast-freezing-quick-thawing method.With pretreatment the relative conductivity of 15% moisture content seed through fast-freezing-quick-thawing treatment was the lowest ;the dehydrogenase activity of 15% moisture content embroy with fast-freezing-quick-thawing, while the a-amylase activity of 10% moisture and the proline content of 15% moisture content were the highest with mild-freezing-quick-thawing method.7.In a whole ,as for the cryopreservation of seed germplasm, especial of recalcitrant seed of tree species,,the key of success is to control moisture c...