In vitro Regeneration of Rudbeckia hirta ‘Plainview Farm’ from Leaf Tissue
NortheastRegion Meeting of ASHS
Rudbeckia hirta L. ‘Plainview Farm’, a new multiple-layered ray flowered cultivar, shows potential for potted plant production. After several years of seed germination, this specific morphological trait was still unstable from generation to generation. To maintain its unique features, new leaves were disinfested using 10% ultra bleach as explants. Leaf sections (0.25 cm2) were cultured on MS medium supplemented with either BA (0.5, 1.0, and 2.0 mg·L−1), KT (2.5, 5, and 10 mg·L−1), or ZT (0.5, 1.0, and 2.0 mg·L−1) to induce the callus and microshoots at 27.2 ±1.85 °C and 16-hour photoperiod. After cultivation for 33 days, all treatments significantly induced callus, and the callus sizes were 1.5- to 2.4-fold bigger than those with no cytokinin. KT (2.5 mg·L−1) was the better cytokinin concentration for callus induction and microshoot formation. A total of four microshoots per explant could be produced from that KT concentration. All induced microshoots were cultured on MS medium at its one-quarter strength containing either IBA or NAA (0.5, 1.5, and 3.0 mg·L−1). No significant rooting difference was observed in comparison with the control (no auxin). The plantlets were transplanted, acclimated in a mist system, and grown in a greenhouse. A total of 96.4% of the potted plants derived from tissue culture were multiple layers of ray flowers, with only 9.6% from seed germination. Therefore, in vitro regeneration of ‘Plainview Farm’ was a feasible way to produce the double-flowered plants.
In Vitro Regeneration of Rudbeckia Hirta ‘Plainview Farm’ from Leaf Tissue, Northeast Region Meeting of ASHS, Newark, DE, 10 January 2009.