Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis ...Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis in protocorm-like-bodies （PLBs） of C. insigne was studied. Synthetic phytohormones such as BA and TDZ （cytokinins） and NAA （auxin） were used for comparison. PLBs of C. insigne were explanted on modified Murashige and Skoog medium supplemented with the single addition of chitosan and NAG, and the combination of BA （benzyladenine） and NAA （1-naphthaleneacetic acid） also with the combination of NAA and TDZ （thidiazuron） among different concentrations. Combination treatments of auxin and cytokinins, the highest percentage of PLBs formation was 73% and shoot formation was 67% when cultured on the medium supplemented with 1.0 mg L1 BA without NAA. Combination treatment of NAA and TDZ, the PLBs formation was 90% and shoot formation was 60% obtained from medium supplemented with 1.0 mg Lt of NAA ＋ 0.1 mg L^-1 TDZ. Single addition of chitosan and NAG with modified MS medium was more effective for new PLBs and shoot formation. The highest percentage of PLBs formation was 87% and shoot formation was 80% obtained from the medium supplemented with 0.1 mg L^-1 chitosan. On the other hand, the PLBs formation rate reached 93% and shoot formation rate was 87% obtained from the medium supplemented with 0.01 mg L^-1 NAG. Application of polysaccharides to in vitro orchid PLBs allows developing new PLBs and shoot to form plantlet without synthetic phytohormones.展开更多
Protocorm-like bodies （PLBs） or thin cell layers （TCLs） derived from PLBs of hybrid Cymbidium Twilight Moon ＇Day Light＇ can induce new or neo-PLBs on Teixeira Cymbidium （TC） medium, which contains 0.1 mg/L a- ...Protocorm-like bodies （PLBs） or thin cell layers （TCLs） derived from PLBs of hybrid Cymbidium Twilight Moon ＇Day Light＇ can induce new or neo-PLBs on Teixeira Cymbidium （TC） medium, which contains 0.1 mg/L a- naphthaleneacetic acid, 0.1 mg/L kinetin, 2 g/L tryptone and 20 g/L sucrose, and is solidified with 8 g/L Bacto agar. This study aimed to assess the response ofneo-PLB formation to an ethylene-liberating compound （2-chloroethylphosphonic acid （CEPA））, to two ethylene inhibitors （silver nitrate （AgNO3） and aminoethoxyvinylglycine （AVG））, and to aeration （made possible by using Milliseal~ or autoclaved filter paper）. AgNO3 at 1 or 2 mg/L in TC medium significantly increased the fresh weight of PLBs while 1 mg/L of AgNO3 also showed a significant increase in the number ofneo-PLB from both half-PLBs and from tTCLs. In contrast, AVG and CEPA inhibited neo-PLB formation. Neo-PLB formation from half-PLB or TCL explants in the presence of aeration resulted in significantly lower neo-PLB weight. The use of AgNO3 and aeration are alternative means to mass produce neo-PLBs for micropropagation purposes.展开更多
文摘Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis in protocorm-like-bodies （PLBs） of C. insigne was studied. Synthetic phytohormones such as BA and TDZ （cytokinins） and NAA （auxin） were used for comparison. PLBs of C. insigne were explanted on modified Murashige and Skoog medium supplemented with the single addition of chitosan and NAG, and the combination of BA （benzyladenine） and NAA （1-naphthaleneacetic acid） also with the combination of NAA and TDZ （thidiazuron） among different concentrations. Combination treatments of auxin and cytokinins, the highest percentage of PLBs formation was 73% and shoot formation was 67% when cultured on the medium supplemented with 1.0 mg L1 BA without NAA. Combination treatment of NAA and TDZ, the PLBs formation was 90% and shoot formation was 60% obtained from medium supplemented with 1.0 mg Lt of NAA ＋ 0.1 mg L^-1 TDZ. Single addition of chitosan and NAG with modified MS medium was more effective for new PLBs and shoot formation. The highest percentage of PLBs formation was 87% and shoot formation was 80% obtained from the medium supplemented with 0.1 mg L^-1 chitosan. On the other hand, the PLBs formation rate reached 93% and shoot formation rate was 87% obtained from the medium supplemented with 0.01 mg L^-1 NAG. Application of polysaccharides to in vitro orchid PLBs allows developing new PLBs and shoot to form plantlet without synthetic phytohormones.
文摘Protocorm-like bodies （PLBs） or thin cell layers （TCLs） derived from PLBs of hybrid Cymbidium Twilight Moon ＇Day Light＇ can induce new or neo-PLBs on Teixeira Cymbidium （TC） medium, which contains 0.1 mg/L a- naphthaleneacetic acid, 0.1 mg/L kinetin, 2 g/L tryptone and 20 g/L sucrose, and is solidified with 8 g/L Bacto agar. This study aimed to assess the response ofneo-PLB formation to an ethylene-liberating compound （2-chloroethylphosphonic acid （CEPA））, to two ethylene inhibitors （silver nitrate （AgNO3） and aminoethoxyvinylglycine （AVG））, and to aeration （made possible by using Milliseal~ or autoclaved filter paper）. AgNO3 at 1 or 2 mg/L in TC medium significantly increased the fresh weight of PLBs while 1 mg/L of AgNO3 also showed a significant increase in the number ofneo-PLB from both half-PLBs and from tTCLs. In contrast, AVG and CEPA inhibited neo-PLB formation. Neo-PLB formation from half-PLB or TCL explants in the presence of aeration resulted in significantly lower neo-PLB weight. The use of AgNO3 and aeration are alternative means to mass produce neo-PLBs for micropropagation purposes.
