TY - JOUR AU1 - Penzkofer, Michael AU2 - Baron, Andrea AU3 - Naumann, Annette AU4 - Krähmer, Andrea AU5 - Schulz, Hartwig AU6 - Heuberger, Heidi AB - Background: The essential oil is an important compound of the root and rhizome of medicinally used valerian (Valeriana officinalis L. s.l.), with a stated minimum content in the European pharmacopoeia. The essential oil is located in droplets, of which the position and distribution in the total root cross-section of different valerian varieties, root thicknesses and root horizons are determined in this study using an adapted fluorescence-microscopy and automatic imaging analysis method. The study was initiated by the following facts: • A probable negative correlation between essential oil content and root thickness in selected single plants (elites), observed during the breeding of coarsely rooted valerian with high oil content. • Higher essential oil content after careful hand-harvest and processing of the roots. Results: In preliminary tests, the existence of oil containing droplets in the outer and inner regions of the valerian roots was confirmed by histological techniques and light-microscopy, as well as Fourier-transform infrared spectros- copy. Based on this, fluorescence-microscopy followed by image analysis of entire root cross-sections, showed that a large number of oil droplets (on average 43% of total oil droplets) are located close to the root surface. The remaining oil droplets are located in the inner regions TI - Characterization of essential oil distribution in the root cross-section of Valeriana officinalis L. s.l. by using histological imaging techniques JF - Plant Methods DO - 10.1186/s13007-018-0309-4 DA - 2018-06-04 UR - https://www.deepdyve.com/lp/springer-journals/characterization-of-essential-oil-distribution-in-the-root-cross-Wsx031KNua SP - 1 EP - 15 VL - 14 IS - 1 DP - DeepDyve ER -