Studies On In Vitro Culture Of Flower Organs In Cymbidium Longibracteatum

In this study, spring sword (C.longibracteatum) flower organs (flower bud, flower stalk, gynostemium, calyx, pedicel) were used as explants for in vitro culture. The objectives were to elucidate the effects of different cutting methods, different basic media and different hormones on the browning, growth initiation and callus induction, also by different browning inhibitions to study the effect on browning in flower stalk. The full design, orthogonal design, combined with analysis of variance, multiple range annalysis, multiple comparisons and other statistical methods were employed to determine the factors and culture conditions. The results showed that:1 The longitudinal cutting was the best for flower buds,stalks and while pedicel, horizontal inscribed injury was suitable for calyx, gynostemium were better in non-cutting.2 For callus induction and growth of organs:(1) The best medium for callus induction from flower stalk was B5+2,4-D2.0mg/L +TDZ0.6mg/L+GA30.5mg/L, resulting in 7.32% of callus induction.2,4-D had significant effect on the callus inductiong, the suitable concentration was 2mg/L(2) No effects were found in the different hormones on the induction of callus in flower bud, gynostemium, calyx and pedicel, although the obvious changes were observed. Gynostemium and pedicel formed uneven surface, showing the potential trend of callus occurrence.3 Effects of different treatment on browning:(1) When the length of flower bud was 2cm, the flower stalk had low browning rate.(2) Flower stalk explants of 8mm thickness had the lowest rate of browning.(3) PVP, VC, Citric acid and 8-HQS had significant effects on browning control, but 8-HQS displayed best results with 33.82% of lower browning rate than the control. (4) Cold pretreatment also had significant effect on browning control, and 2℃for 24h was the best, resulting in 35.99% of lower browning rate than the control.(5) Thermal shock of 45℃for 10min could effectively reduce browning rate,39.11% lower than the control. But in thermal shock severer than 50℃for 120s, browning rate was 5.40% higher than the control.(6)The more frequent the transference, the lower browning of pedicel. The transference once a day showed the best effect on reduing the browning of flower stalks, in which the browning rate was 44.52% lower than the control.(7) When temperature was 15℃, the browning rate was 30.42% lower.