Search and Access Archived Conference Presentations

The 2009 ASHS Annual Conference

2174:
Effects of Ethylene Associated Compounds On In Vitro Growth and Differentiation of Cymbidium Sinense Rhizomes In Media for Rhizome Propagation and Shoot Differentiation

Saturday, July 25, 2009
Illinois/Missouri/Meramec (Millennium Hotel St. Louis)
Yao-Chien Alex Chang, Dept. of Horticulture, National Taiwan University, Taipei 10617, Taiwan
Jhen-Ying Pan, Dept. of Horticulture, National Taiwan University, Taipei 10617, Taiwan
Nean Lee, Dept. of Horticulture, National Taiwan University, Taipei 10617, Taiwan
The gaseous plant hormone, ethylene, can induce a great range of plant responses in growth and development. In tissue culture, ethylene may promote or inhibit shoot formation, depending on species. Rhizome culture of Cymbidium sinense in cytokinin-free medium resulted in rhizome proliferation but shoot differentiation in cytokinin-added medium. In this study, we investigated the effects of 1-aminocyclopropane-1-carboxylic acid (ACC), aminooxyacetic acid (AOA), and AgNO3 on shoot formation in rhizome culture. Rhizome sections of Cym. sinense 'Rui Bao' x Cym. sinense 'Guang Hua Die' was used as plant material; each chemical was tested at concentrations of 0, 50, and 100 μM. Ethylene evolution was monitored by gas chromatography. Supplementing ACC in rhizome propagation medium promoted rhizome growth and branching; adding AgNO3 suppressed rhizome growth but increased shoot differentiation and growth. In shoot differentiation medium, adding ACC significantly inhibited shoot and root growth, while AgNO3 increased shoot growth. These results implied that ethylene may promote rhizome growth but inhibit shoot formation in Cymbidium sinense, thought it should be further confirmed. The addition of ACC or AgNO3 increased ethylene evolution. It seemed that AgNO3 increased ethylene synthesis but inhibited ethylene action. Adding 50 or 100 μM AOA in both media resulted in suppressing rhizome and shoot growth; it may be attributed to that these concentrations were too high and caused toxicity.