Fig 2. Determination of viability of early Picea abies somatic embryos in eight week old clusters (non-vital staining).

(A) Schematic of the cluster structure of ESEs; (1) view from the top and (2) bottom, (a) inner part of cluster and (b) outer part of cluster. (B) Staining with 2,3,5-triphenyltetrazolium chloride (TTC). (C) Staining with acetocarmine; (a) embryos from the inner cluster, (b) embryos from the outer cluster.