Study On Virus-Elimination And Rapid Propagation Of Many Flower Betony (Stachys Floridana Schuttl.ex Benth.)

The culturation of the tip meristem of many flower Betony which was about 0.3-0.5 mm in length with 1 or 2 primordia leaves had been investigated on different culture medium. At the same time, the effect of different techniques on the virus-free rate of regeneration planlets by tip meristem cultured in vitro, the regeneration and rapid propagation system were studied, too. The results showed:As the basic medium for many flower Betony culturation in vitro, MS was the best in all media include White, MA, B5 and Ne. The optimal medium for the tip meristem culture was MS+6-BA 0.5 mg/L+NAA 0.1 mg/L+sucrose 4%, on which 74.1% plantlet ratio was produced. The different treatment to produce virus-free plantlet by the tip meristem culture was studied. The results showed that the size of excised shoot tip was negative correlated with the virus-free rate of plantlet. Too smaller shoot tip make operation and regeneration difficult. The attempt of using 0.5 mm length shoot tip was successed with 71.4% plantlet rate and 30.0% virus-free rate produced. The virus-free rate could be increased markedly by using the tip meristem culturation technique together with the techniques such as cut of stem tip more than one times, higher temperature pre-treatment of the planr material. However the survival rate might be degraded. The suitable method to obtain virus-free plantlet was to pre-treat the plants at 42℃ for 15 days firstly, and then to cut the shoot tip(0.5 mm long) one times. 50.0% survival rate and 57.1% virus-free rate were gained with this method.Explants in different development period showed differences in callus induction.The younger and tender the explants were, the better the callus induction would be. Leaf discs, stem segments and anther could all be induced to produce callus, and the induction rate could reach 100%. However, only 61.2% induction rate was got from anther. The callus from variant explants showed differences in buds differentiation. Adventitious buds can be obtained from leaf and stem callus ,but not from anther callus.The best medium for leaf discs to induce callus was MS+6-BA 2.5 mg/L+NAA 1.5 mg/L+IAA 1.0 mg/L. It wassuitable to induce callus from stem segments and anther on MS+6-BA 2.0 mg/L+NAA 1.5 mg/L+IAA 0.5 mg/L. The best adventitious buds induction medium for leaf and stem callus was MS+6-BA 1.0 mg/L+NAA 0.8 mg/L+GA3 2.0mg/L, with 71.4%, 78.6% induction rate, respectively.The stem apex, leaf disc and stem segments as explants were used to study the effects of different hormones treatments on the adventitious bud induction and propagation.The results showed that stem apex and stem segments had low reproducing rate with only got 5-7 buds per explant in longer buds induction, while leaf disc had not showed ability to reproduce.The best way to get more reproducing plantlet (14.3 per explant)was to lengthen the bud from the bud lump which was gotten from the induced stem segments on MS medium supplemented with 6-BA 5.0 mg/L. The bud lump can be propagated for a long time and the reproducing ability would not decreased on MS medium with 6-BA 4.5 mg/L and GA3 1.0 mg/L. The better medium for bud elongation is MS+6-BA 1.5 mg/L +NAA 0.4 mg/L +GA3 0.5 mg/L.The effects of the photoperiod, temperature, sucrose, 6-BA and CCC on in vitro stolon induction were studied. The results showed that dark cultural condition is essential to stolon induction. Short photoperiod (8h/d) and long photoperiod (14h/d) would make stolons grow into branches. Lower sucrose concentration (3%) inhibited stolon induction and only got feeble branches were produced. If 6-BA 5mg/l and CCC 500mg/L be supplemented to the medium, smaller stolon could be formed. This procession was apparently promoted by higher sucrose concentration. 6-BA and CCC were not essential to stolon induction, but they could significantly accelerate the development of stolon and enhance the average output per plantlet. The situable temperature was 20℃. Higher temperature may degrade the stolon number.1/2MS medium with 0.5 mg/L NAA and 3% activit...