Drought Stress Responses of Prunus microcarpa C. A. Mey. subsp. tortusa Rootstocks under in vitro Conditions

Abstract

Background: Prunus microcarpa C.A. Mey. subsp. Tortusa (MK), a wild deciduous plant species, is native to Caucasus and West Asia and grows in a dry temperate climate zone. The plant is mainly used to obtain a dark greyish green dye from its leaves and it has an economic value due to ornamental characteristics. Therefore, this study aimed to determine the appropriate Polyethylene Glycol 8000 (PEG) doses for early detection of drought resistance using MK, SL-64, Garnem, Pixy and Gis-6 rootstocks.

Methods: The microshoots of each rootstock were planted at the end of the fourth subculture in Magenta GA7 vessels containing NRM medium. The medium contained 1.0 mg L-1 BA + 0.01 mg L-1 IBA supplemented with 30 g L-1 sucrose, gelled with 5.5 g L-1 agar and 0, 2, 3 and 4% PEG doses (four treatments). The cultures were kept at 23 +/- 2 degrees C temperature under 16 h light (80 mu mol m(-2) s(-1)) and 8 h dark photoperiod.

Result: The highest number of shoots was recorded in control treatment for MK rootstock (2.81 shoots plant(-1)) and in 4% PEG treatment for Gis-6 rootstock (2.81 shoots plant(-1)). Mean chlorophyll a (10.66 mg/f.w) and chlorophyll b (3.63 mg/f.w) contents in the control treatment were lower compared to the mean chlorophyll a (2.03 mg/f.w) and chlorophyll b (1.15 mg/f.w) contents of plants grown in PEG 4% dose. Prunus microcarpa genotypes of Turkey origin tested in this study could be used as potential rootstocks in arid and semi-arid region as safe as the other standard rootstocks tested.