Light Source and Cytokinin Type Affect Multiplication Rate, Chlorophyll Content and Stomata Formation of Amelanchier alnifolia Shoots in Vitro

Abstract

Amelanchier alnifolia, a deciduous shrub or small tree with edible berry-like fruit, is gaining importance as a commercial fruit crop. The application of micropropagation could complement conventional propagation methods of A. alnifolia. The present study aimed to investigate how two light treatments—a mix of red and blue LED lights with dominant wavelengths of 457 and 658 nm (RB LED) and conventional fluorescent lamps emitting light at broad wavelengths of 400-700 nm (FL)—in combination with three cytokinins (CK) belonging to either substituted adenines (6-benzylaminopurine, BAP; meta-Topolin, mT) or to phenylurea cytokinins (thidiazurone, TDZ) affected the multiplication rate, chlorophyll content, and stomata formation in in vitro culture of A. alnifolia axillary shoots. The two light sources proved equally effective in producing axillary shoots, but FL favorably influenced the elongation and chlorophyll content. On the other hand, RB LED lights triggered a significantly higher stomata number of A. alnifolia plantlets in vitro compared with those developed under FL. Presented results reveal a negative ratio between the stomata number and chlorophyll content in response to different cytokinins: TDZ induced the highest number of stomata while BAP significantly increased the chlorophyll content. As the largest number of axillary shoots per explant was achieved on the medium with addition of TDZ, it could be beneficial to use TDZ for multiplication, whereas the use of BAP could be advantageous in the last passage of multiplication before rooting.

Keywords

• led light
• fluorescent light
• cytokinin
• bap
• mt
• tdz
• in vitro propagation
• chlorophyll content
• stomata formation