Popis: |
Effectsof jasmonic acid (JA) and sucrose on tuber formation were studied in a commontuberous terrestrial orchid Pterostylis sanguinea D.L.Jones& M. Clements (dark banded greenhood orchid) from southwestern Australia.Seeds were germinated symbiotically in vitro on an oatmealagar (OMA) in the presence of a mycorrhizal fungus isolated from the orchidhost. Ten week-old seedlings were transferred into culture vessels containingOMA supplemented with JA (at concentrations 0, 0.1, 1, 5 or 10μM), sucrose (at concentrations 0, 5, 10 or 20 gl−1) or combinations of each. Tuber development in alltreatments occurred approximately twenty-six weeks after seed sowing. Theaddition of 5 or 10 g l−1 sucrose with JA to themedia resulted in higher frequencies of tuber formation in comparison to thecontrol. Significantly higher proportion of seedlings produced tuber when themedium was supplemented with 5 g l−1 sucrose incombination with 5 μM JA, compared to the control.In vitro tuber formation of Pterostylissanguinea can be improved by combined addition of appropriate levelsof JA and sucrose to OMA, which will aid in rapid in vitrotuberisation of terrestrial orchids. |