Exploratory Studies On In Vitro Flowering Of The Hybrid Plbs And Plantlets From Cymbidium Longibracteatum×Cymbidium Hybridium

Studies on in vitro flowering were carried out using the hybrid PLBs and plantlets of Cymbidium longibracteatum’cuixian’ and C. hybridium Enzan Stream’Orpheus’as material. The objective of the studies was to initiate a basic research for in vitro flowering of interspecies hybrids in Cymbidium. The main results are as follows.1. The effects of6-BA on in vitro flowering were not obvious. When concentration of6-BA was2.5mg/L, the induction rates of leaf buds for two materials had the maximum34.78%and19.22%. Plantlets grew slower when the concentration of6-BA was higher.2. The effects of TDZ on in vitro flowering were not obvious. The induction rate of leaf buds was47.89%when the concentration of TDZ was0.6mg/L. The browning was worst when the concentration of TDZ was0.4mg/L.3. The effects of N on in vitro flowering were not obvious with TDZ, high phosphorus content and fluctuated temperatures.1/4N was the best one for the induction of the leaf buds in which the leaf bud induction rates were53.31%and49.29%, respectively. The nitrogen content at too low level resulted in etiolation.4. The effects of sugar on in vitro flowering were not obvious with TDZ, high phosphorus content, low nitrogen content and fluctuated temperature.4%sugar was the best one for the induction of the leaf buds in which the leaf bud induction rates were41.96%and46.56%, respectively. The sugar concentration at too high kevek gave rise to etiolation.5. The effects of ABA on in vitro flowering were not obvious with TDZ, high phosphorus content, low nitrogen content, high sugar concentration and fluctuated temperature. Best induction of leaf buds (49.31%and45.70%) was obtained when the concentration of ABA was0.4mg/L. A bud with flower bud appearances was observed in the variable temperature treatment, but it failed to further develop.6. The effects of PP333on in vitro flowering were not obvious with TDZ0.5mg/L,5P,1/2N and sugar4%. The best concentration of PP333was4mg/L where the leaf bud induction rate was50.57%.7. The effects of N, sugar,6-BA and ABA on in vitro flowering were not obvious. The optimal medium for leaf bud induction was MS(1/4N)+NAA0.2mg/L+AC0.5g/L+sugar4%+6-BA4.0mg/L+ABA0.2mg/L where the leaf bud induction rate was54.84%.