Effect Of Cryopreservation On Physiological Characteristics Of Iris Ensata Seeds And Establishment Of Regeneration System

Iris ensata Thunb is the main research material of this experiment which based on the previous study. We mainly studied the physiological characteristics effect of the dehydration processing and cryopreservation on I. ensata seed, the influence factors for cryopreservation of I.ensata seed and the establishment of callus regeneration system for I. ensata seed in order to lay the foundation of the long-term preservation and development and utilization of germplasm for I.ensata, which can also provide research materials for transgenic engineering research. The main results are as follows,1.I. ensata seeds have strong resistance to dehydration. When the water content of seed reached 5.0%, seed germination rate was 91.00%. The superoxide dismutase (SOD) activity, peroxidase (POD) activity, Catalase (CAT) activity and soluble protein content, proline content, of seed significantly better than seeds without dehydration treatment, and malondialdehyde (MDA) content, conductivity lower than seeds without dehydration treatment. Appropriate dehydration treatment can improve the viability of the I. ensata seeds. We analyzed that the water content of about 5.0% is optimum moisture in the dehydration processing at room temperature.2.I. ensata seeds can be preserved by cryopreservation. Seed moisture and thaw mode are both the key factor for I. ensata seeds cryopreservation. The activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT)and proline content in the seed of 3.6% water content were significantly superior to other seed moisture content after cryopreservation, and malondialdehyde (MDA) content is low. The cultivate seedlings were height and thick, dark green color, emergence and tidy, the best performing growth conditions. The 3.6% water content and tap water thawing were the most suitable for the cryopreservation and thaw mode.3. The shoot tips was regarded as explants, which was disinfected by the method that explants were soaked in 75% alcohol for 30s and disinfect in 0.1% HgCl2 for 8min. The best culture medium for inducing callus was MS+6-BA1.0 mg/L+NAA0.5 mg/L+2,4-D1.0 mg/L. Callus induction rate reached 51.51%. Leaf is not suitable as a callus induction explant for I. ensata.4. The optimum bud induced medium for callus was MS+6-BA 1.0 mg/L+NAA 0.5 mg/L+KT 1.0 mg/L, the differentiation rate of up to 72.31%.5. The optimum rooting induced medium for callus adventitious bud was MS+NAA 1.5 mg/L. The rooting rate was 100.00% and rooting coefficient was 9.80. The roots were very thick.