| Cryptomeria fortunei, as one of main commercial tree species and garden plants in southern China, has taken an important role in timber production and ecological construction. There are nearly all seedlings in production so far, but the yield of elite seeds is small and instability. The asexual reproduction was a little premature to meet the needs of large-scale afforestation. As a consequence, take the seedlings sprouted from Cryptomeria fortunei’s seeds and the stems from adult trees under sterile conditions acted as explants, the effects of different types of basic mediums and plant growth regulators on buds induction, multiplication and root formation were studied and the rapid propagation technique by tissue culture was established in this reseach. Here are the results:(1) Establishment of rapid propagation for sterile seedlings of Cryptomeria fortunei by tissue cultureThe pretreatment of seeds:the seeds were swelled first by a 2 h immersion in 0.3%(W/V)KMnO4 solution followed by a 24 h immersion in water with an initial temperature of 45℃. And then rinsed 5 h by running water after 30 min immersed by 0.1% (W/V) detergent solution. The pretreatment of seeds can enhance the effect of disinfection and stimulate the germination.Rapid immersed with 75% alcohol for 10 s plus 0.1% HgCl2 for 600 s was the best disinfection method for Cryptomeria for tunei’s, seeds after pretreatment with the contamination rate of 10.00% and the highest survival rate was 82.33%. The disinfected seeds were cultured in the media containing 30 g·L-1 sucrose and 7 g·L-1 agar only, then the seeds would sprouted sterile seedlings.The best medium for the buds induction of sterile seedlings was DCR+6-BA 0.2 mg·L-1 with the induction rate up to 73.33%, the cluster buds sprouted rapidly with verdant leaves, well growth and obviously height growth; DCR+6-BA 0.2 mg·L-1+IBA 0.05 mg·L-1/was the most suitable for buds multiplication while average height reaches 5.63 cm, value ratio reaches 11.00 and the cluster buds growth consistently and normality; the optimum for rooting which rooting rate achieved 90.00% was DCR+NAA 0.01 mg·L-1+IBA 0.2 mg·L-1 and the average number of roots was 4.09; the quality of root was good with long and thick taproots associated with lateral root; the suitable matrix for test-tube plantlet was pure sand while the survival rate in transplanting reached 89%.(2) Establishment of rapid propagation for stems of Cryptomeria fortunei by tissue cultureThe pretreatment of stems:heeled in the top stems from adult trees in greenhouse and sprayed a certain amount of 0.2%(W/V) carbendazim solution per week. Then the stems were immersed first by a 30 min immersed by detergent solution followed by rinsed 3 h by running water after brushing the dust on the surface. The pretreatment of stems can control the pollution of explants to a certain extent.Rapid immersed with 75% alcohol for 10 s plus 0.1% HgCl2 for 6 min was the best disinfection method for Cryptomeria for tunei’s stems with the contamination rate of 17.33% and the highest survival rate was 66.67%.The best medium for the buds induction of adult tree stems was WPM+6-BA 0.5 mg·L-1+IBA 0.3 mg·L-1 with the induction rate up to 82.67%, the average number of buds up to 4.27 and the average length of buds up to 3.18 cm, the cluster buds sprouted rapidly with verdant leaves and well growth; The best medium for the buds induction of adult tree stems was also suitable for buds multiplication while the average height reaches 5.12 cm, value ratio reaches 5.13 and the cluster buds growing well overall; the optimum for rooting was DCR+NAA 0.01 mg·L-1+IBA 0.2 mg·L-1, the same as seedlings, while rooting rate achieved 88.26%, the average number of roots were 4.09 and the average length of roots were 11.96 cm, the thick taproots associated with lateral roots sprouted from the base of buds; the transplanting still consistent with the seedlings while the survival rate in transplanting reached 85%. |
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