Effects of gelling agents on growth, mineral composition and naphthoquinone content of in vitro explants of hybrid walnut tree (Juglans regia × Juglans nigra) E Barbas, C Jay-Allemand, P Doumas, S Chaillou and D CornuAnn. For. Sci., 50 2 (1993) 177-186DOI: https://doi.org/10.1051/forest:19930205