Mass propagation of globe artichoke (Cynara scolymus): Evaluation of different hypotheses to overcome vitrification with special reference to water potential

In search of a technique for rapid clonal propagation and sanitation of Cynara scolymus L. we have been confronted with the problem of vitrification. We only succeeded in overcoming this problem by raising the agar concentration of our medium to 1.1% instead of 0.6%. By using the Chardakov‐method and direct measurement of the water potential with a thermocouple psychrometer we were able to prove that this result was attributable to the matric potential.