Reduction of the subculture frequency in three Mediterranean species during micropropagation

C. Mascarello, E. Sacco, D. Di Silvestro, M. Pamato, B. Ruffoni
During micropropagation there are non-productive periods during which the plants can be stored in slow growth at very low temperatures to avoid expensive subcultures. In certain cases, the plants do not survive at this conditions and need particular care. This is the case of several Mediterranean species, such as Ceratonia siliqua L., Arbutus unedo L. and Myrtus communis L. Selected genotypes of these species with already established micropropagation protocols have been grown for maintenance at two temperatures (18 or 24°C) to evaluate the explant survival every 45 days during 6 months of storage without substrate renewal. The media used were: MS salts and vitamins, pH 5.7, agar 8 g L-1 added with: BA (0.1 mg L-1) for C. siliqua, Zea (1 mg L-1) for A. unedo and BA (0.5 mg L-1) + IAA (0.2 mg L-1) for M. communis. Every 45 days, explant samples were evaluated recording growth parameters (explants height, multiplication rate, relative growth rate (RGR), damage (%), death (%) and quality index) and then transferred at 24°C in fresh medium to observe the recovery performances. Results showed that for the three species, at 18°C it is possible to store the material maintaining high quality for up to 135 days. M. communis can be moreover stored for 180 days at the same temperature.
Mascarello, C., Sacco, E., Di Silvestro, D., Pamato, M. and Ruffoni, B. 2017. Reduction of the subculture frequency in three Mediterranean species during micropropagation. Acta Hort. (ISHS) 1155:461-466
carob, myrtle, regrowth, strawberry tree, storage

Acta Horticulturae