Effects of plant growth regulator concentration and light exposure time on in vitro propagation of strawberry (Fragaria x ananassa Duch.)

Strawberry (Fragaria x ananassaDuch.) is a fruit with a characteristic aroma, bright red color, juiciness, and sweetness that is consumed in large quantities. In this study, plant growth regulators (2,4- D: 2,4-dichlorophenoxyacetic acid; BA: 6- enzylaminopurine; IBA: indole-3-butyric acid; NAA: naphthaleneacetic acid), light exposure time (0 h/day, 16 h/day), and MS (Murashige & Skoog) medium, were used to determine the concentration and light exposure time suitable for the process of callus formation, shoot multiplication, and root formation of strawberry plants. The results showed that the MS medium supplemented with 2.0 mg/L 2,4-D under no light condition had the highest callus formation rate (69.3%), and the callus weight was 254.8 mg at 49 days after inoculation. The combination of 0.5 mg/L BA + 0.5 mg/L IBA had the best results in terms of shoot multiplication coefficient (11.9 times), shoot height (3.8 cm), number of leaves/shoot cluster (40.0 leaves), and fresh weight of shoot cluster (2.4 g) after 42 days of culture. The MS medium supplemented with 0.1 mg/L NAA had the highest rooting rate (100%), 17.3 roots/plant with a root length of 2.5 cm, root collar diameter of 2.5 mm, plant height of 5.2 cm, and 5.6 leaves/plant at 21 days after inoculation.