Micropropagation of bog blueberry (Vaccinium uliginosum L.) distributed in Bulgaria

Abstract

The aim of the present study is to develop a system for micropropagation of bog blueberries. They are distributed from 1700 to 2500 m above sea level in the mountains Rila, Pirin, Western and Central Balkan Mountain, Vitosha, Osogovo, Western Sredna Gora and Western and Middle Rhodopes. An approach for the statistical optimization of micropropagation media under laboratory conditions has been applied for the first time. Sterile explants were introduced in vitro on WPM, enriched with 3 mg.l-1 2-iP and pH 4.2. To optimize proliferation, nine variants of WPM were tested with the addition of growth regulators (zeatin and 2-iP) in varying concentrations (1.5 - 3.5 mg.l-1), organic additives (casein hydrolisate and myo-inositol and pH values (4.3 - 4.8). The best result regarding the reproduction coefficient was found on M1 nutrient medium (3.77 pcs/explant), enriched with 3.5 mg.l-1 zeatin and 2-iP, 250 mg.l-1 casein hydrolisate, pH 4.8. The largest average length of shoots was reported on the modified medium M9 with 2.63 cm. The resulting micro shoots were rooted on WPM nutrient medium, halved macrosol content and different levels of IAA (0.5 - 1 mg.l-1), myo-inositol and pH. The highest percentage of rooting was found on R8 nutrient medium with 56.7%.