Micropropagation of Vaccinium arctostaphylos L. via lateral-bud culture

Abstract

The aim of this study was to determine the most suitable growth medium for rapid and efficient micropropagation of Vaccinium arctostaphylos L. (Ericaceae) via lateral-bud cultures. According to preliminary studies, the best explant collection time was late April and May. Accordingly, cuttings were taken from naturally growing V. arctostaphylos populations, and lateral shoot buds were used as explant sources. Anderson's rhododendron medium (AN), McCown's woody plant medium (WPM), and Murashige and Skoog (MS) basal medium, each supplemented with zeatin/indole-3-butyric acid (IBA) (1.0/0.1 mg L^{-1}), were tested to determine the best basal medium for multiple shoot formation; WPM was the most effective basal medium for this purpose. Subsequent shoot multiplication and development studies were carried out with WPM supplemented with an auxin, IBA (0.1 mg L^{-1}), and 2 different cytokinins, zeatin and thidiazuron (TDZ), in various concentrations (0.5, 1.0, and 2.0 mg L^{-1}, respectively). After a 6-week photoperiod (16/8 h, light/ dark) application, zeatin/IBA combinations were found to be the most suitable for shoot multiplication and growth. The highest shoot length (106.53%) was obtained from the medium supplemented with 1.0/0.1 mg L^{-1} zeatin/IBA, while the highest increases in leaf number (141.89%) and multiple shoot proliferation (10.55-fold) were obtained from medium supplemented with 2.0/0.1 mg L^{-1} zeatin/IBA. WPM was also employed as a rooting medium supplemented with different concentrations of IBA (from 0.5 mg L-1 to 8.0 mg L-1) and a 16/8 photoperiod or a completely dark regime. At this stage, the medium supplemented with 0.5 mg L^{-1} IBA was the best rooting growth regulator with 100% rooting success (16/8 photoperiod). Rooted plantlets transplanted into peat and perlite (2:1) substrate were subsequently acclimatized under climate chamber conditions.