Specific features of in vitro micropropagation of various representatives of the genus Rhododendron

One of the best plants for landscaping urban areas are representatives of the genus Rhododendron L. However, there is the problem of obtaining planting material because traditional propagation methods are inefficient or take a lot of time and resources. In vitro micropropagation can be a solution to this problem. The research objects were Rhododendron Helsinky University, Rhododendron hybrid Marianna v. Weizsacker, and Rhododendron caucasicum var. Rosea. Three variants of Woody Plant Medium (WPM) were used for the experiment: with the addition of benzylaminopurine/indolylbutyric acid or naphthylacetic acid/kinetin in the proportion of ¼ mg/l, and a control variant without hormones. The analysis of the effect of different concentrations of phytohormones has demonstrated that for different representatives there are specific combinations of growth regulators. For Rh. caucasicum var. Rosea the hormone-free medium was the most suitable for plant growth as well as the appearance of shoots of order II. For Rh. hybrid Marianna v. Weizsacker, the optimal medium for plant growth was also a hormone-free medium, but the addition of naphthylacetic acid / kinetin enhanced the tillering. The presence of benzylaminopurine / indolylbutyric in the medium had a negative effect on the species and the hybrid. The use of these hormones for Rh. Helsinky University resulted in stimulation of growth and tillering of the plant, while naphthylacetic acid / kinetin hormones caused a depressing effect.