Results of using premature inflorescences as starting material for the in-vitro establishment and the micropropagation by direct adventitious shoot formation from of Valeriana officinalis L. s.l.

In this study a method was founded to generate genetically uniform plant material for the breeding work on valerian (Valeriana officinalis L. s.l.) at the Bavarian State Research Center for Agriculture (LfL). Explants were taken from young inflorescences and transferred to in-vitro culture. The Murashige&Skoog based establish-medium contained 0.5 mg/l benzylaminopurine (BAP), the growth-medium 5 mg/I BAP. Roots were formed also without auxins or without a reduction of cytokinin. The temperature in the culture chamber was between 22 and 24 degrees C, and the culture room was illuminated in a twelve hour alternation. The plant clusters, grown from the explants, were separated into single plants, which were used for new propagation cycles. In total, three propagation cycles were applied. The total growth rate determined after approximately 32 weeks of cultivation averaged at 1:85. The addition of an antibiotic to the establish-medium showed no improvement against contamination with visible pathogens in the culture vessels. However, a higher propagation rate was observed. The tested in-vitro propagation method, using flower-bud explants and subcultures of lateral shoot-clusters, yielded satisfactory propagation rates and could be successfully adapted to the breeding material.