Teresa Cybularz-Urban, Ewa Hanus-Fajerska

Abstract. The study concerning the organogenetic reaction of micropropagated orchid tissues coinfected with Cymbidium mosaic virus and Odontoglossum ringspot virus and of respective healthy control clone is presented.

Experiments on morphogenetic abilities of Cattleya shönbrunensis × C. leopoldii gutata mericlones

Summary

The course of shoot and root regeneration of Cattleya shönbrunensis × C. leopoldii gutata clone infected with CyMV and ORSV was compared with healthy clone of respective hybrid during micropropagation stage of previously obtained mericlones. Shoots obtained from meristematic explants were cultured on solidified MS medium modified according to Kozak (1991) with addition of 2.0 mg·dm^-3 adenine sulphate, 9.7 mg·dm^-3 ascorbic acid and 4.95 mg·dm^-3 BA, 1.0 mg·dm^-3 NAA, 0.125 mg·dm^-3 2.4-D. Control healthy tissues were characterized by significantly higher multiplication rate in comparison to the contaminated material, whereas in CyMV and ORSV infected tissues temporal stimulation of shoot development was observed. The values of micropropagation coefficient were from 3.2 to 6.5 in infected material, depending on the examined passage during the six months period. The respective values of control clone were equal, or above ten. Virus infected cultures exhibited rather stable tendency to form aerial roots during every micropropagation passage, contrary to the reaction observed in healthy material. The viral replication in tissues brought about a clear decrease in fresh and dry matter of cultured tissues, the respective values being statistically significant. Plantlets obtained by micropropagation were successfully acclimatized to the greenhouse conditions, irrespective of health condition.