The Cryopreservation Of Euonymus Bungeanus And Analysis Of The Effect After Cryopreservation

In this paper,Euonymus bungeanus was taken as experimental material.We used dif ferent preservation methods to study the cryopreservation of Euonymus bungeanus germ plasm resource,including seed,pollen and shoot tips.After cryopreservation,the vitality and related physiological indexes of preservation materials were determined to compare the effects of different preservation methods and select the best one.The conclusions are as follows:1.For the cryopreservation of Euonymus bungeanus seed,moisture content and fre ezing methods are main factors after cryopreservation.The results showed that: the ge rmination rate of different moisture content of Euonymus bungeanus seeds could reach more than 92% before cryopreservation.the seed germination rate which moisture conte nt is 8.0% is 62% by rapid freezing method,which is higher than that of other water contents;the activity of peroxidase,superoxide dismutase and dehydrogenase of the see d with moisture content of 8.0% is higher than that of other seed moisture content;the relative conductivity and malonaldehyde of the seed with moisture content of 8.0% are consistent with the seed before cryopreservation,while the other water content of seed s are increased by different degrees;the activity of catalase of the seed with moisture content of 8.0% is consistent with the seed before cryopreservation,while the other wa ter content of seeds are decreased by different degrees.Therefore,the preservation effec t of seed with moisture content of 8.0% by rapid freezing cryopreservation is the best.2.For the cryopreservation of Euonymus bungeanus pollen,the results indicated th at: the optimum concentration of sucrose and boric acid of Euonymus bungeanus pollen germination is sucrose 100g/L + boric acid 150mg/L,of which the pollen germination rate up to 18.23%.The optimum incubation time and incubation condition were 2h a t room temperature.The highest pollen vitality is 16:00 in a day.After cryopreservation,the germination rate of the pollen with moisture content of 4.14% by 30 min after tha wing at room temperature is highest,of which the pollen germination rate up to 13.02%.3.For the cryopreservation of Euonymus bungeanus shoot tips,the shoot tips tissu e culture system of Euonymus bungeanus was built and the shoot tips cryopreservation system was established on this basis.The results showed that: Euonymus bungeanus sh oot tips is taken as explants which are sterilized by the way that 75% alcohol 10s+0.1%HgCl24min.Then these shoot tips are cultured on the MS medium with 6-BA1.0 m g/L+NAA0.1 mg/L for callus induction the induction rate of which is up to 98%.When the callus show up,these callus is cultured on the MS medium with 6-BA1.5mg/L+NAA0.2mg/L for bud differentiation and proliferation;the differentiation rate is 99% an d proliferation coefficient is 3.21;moreover,the differentiation buds grow well.As for the shoot tips cryopreservation system of Euonymus bungeanus,procedure was establish ed as follows: Sterile shoot tips with a length of 2~3mm are excised under a stereo m icroscope,which are precultured in liquid MS medium with 0.4mol/L sucrose for 2 day s.Then these shoot tips are loaded in loading solution for 10 min and dehydrated with PVS2 solution for 60 min at 0?.After cryopreservation,shoot tips are treated with upl oading solution for 10 min and cultured on the MS medium with 6-BA1.0 mg/L in the dark for 7 days for recovery culture the survival rate of which is over 75%.