THE EFFECT OF NUTRIENT MEDIA IN MICROPROPAGATION AND IN VITRO CONSERVATION OF WILD POPULATION OF MAHALEB CHERRY (PRUNUS MAHALEB L.)

Abstract

Shoot tips of Prunus mahaleb L. isolated from wild populations of Zejmen (Lezhe), promising as rootstocks for sweet cherry cultivars, were submitted to in vitro culture to test if micropropagation could be used for their rapid production. This study was carried out to determine the optimal nutrient media for micropropagation and to develop a suitable protocol for mid-term storage of Prunus mahaleb L. germplasm. For micropropagation were tested three different basal media MS, WPM and LP, all the three combined with 0.3 mg l-1 BAP, 0.1 mg l-1 IBA, 0.3 mg l-1 GA3. The highest shoot length (5.53 cm) was observed on explants cultured on MS media, whereas this parameter was reduced on explants cultured on WPM and LP media (4.63 and 2.10 respectively). During subculture stage, MS and WPM media didn’t show statistical differences regarding to shoots number/explants and leaves number/explants. The rooting percentages of plantlets ranged from 10 to 90%, depending on NAA concentration in the rooting media. In order to find out a medium-term in vitro preservation protocol effect of reduced sucrose and MS salts concentrations and elimination of PGRs from nutrient media on a collection of 30 days old of in vitro wild mahaleb cherry nodal segments have been examined for different periods. The highest survival and regeneration percentage (respectively 93.36 % and 83.72 %) were found in cultures stored at ½ MS media without sucrose for the period of 3 months. The maximal time of conservation without subculture on reduced sucrose and MS salt (1/2MS) concentrations is up to 5 months and in basal MS media without PGRs is up to 3 months. Hence the shoot tips of Prunus mahaleb L. can be successfully stored in vitro for medium terms at ½ MS media without sucrose.