| Two regeneration systems were established respectively on Cynanchum auriculatum through two approachs: one was inducement and differentiation of callus with leaf, stems , seeds and radicles as explants and the other was inducement of clustered shoot. The main results can be summarized as follows:1. Inducement of callus: The effects of different medium and hormone combinations on callus formation were greatly,the best basic medium is MS ,and auxin 2,4-D is a key factor in callus formation. Callus could be induced by different explants including leaf, stem and seed, but induce ratio and growth form of callus were different from each other. It was proved that stem was the best explant for inducing callus.2. Inducement and proliferation of buds: The callus turned green and formatted many buds after transferred into the culture medium, and then clustered shoot was formatted. The best medium for differentiation was KT2.0 mg.L-1+ NAA0.1 mg.L-1,and the highest differentiation rate could reach to 74.3%. Roots began to grow after the callus were transferred into the rooting medium. On the 1/2MS medium with IAA 0.2mg.L-1 and NAA 0.5mg.L-1, the highest rooting rate could reach to 89.5%, NAA was the key factor for changing the form.3. Inducement of clustered shoot and regeneration system was established: Shoot could induce with axilla bud , stem and stem tip as explant, and the best culture medium was MS+KT1.0mg.L-1+NAA 0.1mg.L-1, on which the highest induce ratio was 100.0%. The best culture medium for subculture was MS+KT1.5 mg.L-1 +NAA0.05 mg.L-1, and the highest differentiation time was up to 5.6.4. Influence of agar concentrations on callus browning and vitrification:The callus multiplication times could reach to 4.9 and the callus grew fast and good when agar concentration was 8g.L-1.Callus Browning rate increased as agar concentrations iccreased. The browning was very serious when it above 8.5g.L-1 while vitrification was very serious when it under 7.5 g.L-1.
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