Achieving desired plant growth regulator levels in liquid plant tissue culture media that include activated carbon.

This paper is part of a series considering the impact of activated carbon (AC) on the composition of plant tissue culture media. Using liquid culture media for initiation of Norway spruce embryogenic tissue and eight different ACs, we present a method for achieving target plant growth regulator (PGR) levels in AC-containing medium based on sorption isotherms for individual PGRs. Linear relationships were found between PGR adsorption and specific BET (Brunauer, Emmett, Teller theory) surface area and specific total pore volume of AC. When using a new AC, this linear relationship allows one to achieve multiple PGR levels similar to historic levels through adjustment of the mass of AC based on its relative BET surface area or relative total pore volume. Target levels of PGRs and an initiation success similar to that in medium without AC were achieved with several different AC types when AC mass was adjusted on the basis of pore volume.