A white flowering Eastern redbud (Cercis canadensis var. alba L.) has been successfully micropropagated. Two node explants collected from the initial flush of spring growth were cultured on woody plant medium (WPM). Increased shoot multiplication occurred at 10,15 and 20 μM (2.3, 3.4 and 4.5 ppm) benzyladenine (BA). Microshoots were rooted in vitro on half strength WPM with a 15-day treatment of 100 and 300 μM (18.6 and 55.9 ppm) α-naphthaleneacetic acid (NAA) or 100 and 300 μM (20.3 and 60.9 ppm) indolebutyric acid (IBA) prior to being moved to full strength WPM without growth regulators. Percentage rooting and the mean number of roots per cutting were comparable between NAA and IBA treated microcuttings, however, the subsequent root morphology differed between the two treatments. NAA treated plants developed a coarse, unbranched root system, while IBA treated cuttings developed a more desireable fine, branched root system. Rooted microshoots were successfully acclimated to greenhouse conditions.
Published as Kentucky Agriculture Experiment Station Jounral Article 90-10-57.
2Graduate student, assistant professor and lab technician, resp.