Abstract:Adventitious buds were induced from peduncle buds and leaves of nine Phalaenopsis varieties on the same media,so as to compare the differences of shoot induction rates and propagation coefficients among varieties.On the basis of above results,three representative varieties,‘Neyshan guniang’,‘Brother Dream “L” ’ and ‘Kaleidoscope’ were selected,which had the maximum,medium and minimum propagation coefficient,respectively,to optimize the adventitious bud propagation condition.Meanwhile,the effects of heat-shock treatment on explants browning were studied with the highest browning degree variety ‘Neyshan guniang’.The results showed that:(1)There were significant differences on adventitious bud induction rates among different varieties,and so were propagation/differentiation coefficients.In the experiment,it had been observed that high flower stalk bud induction rates and propagation coefficients were accompanied with high leaf in vitro shoot induction rates and differentiation coefficients.(2)The major influence factor of shoot proliferation in vitro was 6-benzylaminopurine (6-BA),followed by coconut milk.The suitable medium for adventitious bud propagation of ‘Neyshan guniang’ and ‘Brother Dream “L” ’ was 1/2 MS+7.0 mg·L-1 6-BA+0.2 mg·L-1 NAA+100 mL·L-1 coconut milk,and the medium 1/2MS+5.0 mg·L-1 6-BA+0.2 mg·L-1 NAA+50 mL·L-1 coconut milk was appropriate for the adventitious bud propagation of ‘Kaleidoscope’.(3)Explants browning could be significantly inhibited by heat shock at 40℃ for 9 min.Browning index,total phenol content and PAL activity were significantly below against CK in leaves cultured after heat shock treatments,and they had very significantly positive correlation.These proved that short time of heat-shock could reduce PAL activity and phenol compounds accumulation,thus reduce brown injury in the process of culture.