ISHS Acta Horticulturae 167: II Symposium on Growth Regulators in Floriculture
THE IN VITRO PROPAGATION OF THE TETRAPLOID FORMS OF RUDBECKIA HIRTA |
| Authors: | Z. Kovacs, E. Ladanyi |
| Abstract:
Favoured by growers for its yellow and brown colours, Rudbeckia hirta has been cultivated for a long time. The breeding of this plant is getting more importance these days. Beside the diploid species tetraploid ones have been produced, too. When these forms are cultivated too late, some problems arise in the seed crop. It is especially hard to get ripe seeds from the most beautiful and most vigorous specimens. Selection of these populations offers new possibilities. We tried to winter those plants that had been found surviving late and borne hardly any seeds. Wintering these plants in cold-frames (cold-beds) we got surprising results. Plants admired only for their drought tolerance up to now started blooming without any heating at the end of February. Producing clones, suitable for early blooming without heating, from a not egualized population was considered. That's why we tried the in vitro propagation, which was a new method with this species. As a result of cooperation between the Fruit and Ornamental-Plant Developing Company in Budapest (the former Horticultural Research Institute) and the Rozmaring Agricultural Cooperative, the in vitro-propagated off springs of specimens selected in the last year started blooming in the first days of July under open-air conditions. We found invitation of sterile tissue culture to be very difficult. For the buds' sterilization we used HgCO2 (2000 ppm) for five minutes. After this we washed the buds three times in sterile water. The buds were sterilized a second time by Chlorogen (2000 ppm) for 5–6 minutes, and afterwards washed again. The medium is MS macro- and microelements with 80 mg/l adenine sulphate, 10 mg/l kinetin, 0,5 mg/l IAA for the multiplication and 0,5 mg/l IBA for rooting. | |
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