title: Imaging of Norway spruce early somatic embryos with the ESEM, Cryo-SEM and laser scanning microscope.
abstract: This article describes the surface structure of Norway spruce early somatic embryos (ESEs) as a typical culture with asynchronous development. The microstructure of extracellular matrix covering ESEs were observed using the environmental scanning electron microscope as a primary tool and using the scanning electron microscope with cryo attachment and laser electron microscope as a complementary tool allowing our results to be proven independently. The fresh samples were observed in conditions of the air environment of the environmental scanning electron microscope (ESEM) with the pressure from 550Pa to 690Pa and the low temperature of the sample from -18°C to -22°C. The samples were studied using two different types of detector to allow studying either the thin surface structure or material composition. The scanning electron microscope with cryo attachment was used for imaging frozen extracellular matrix microstructure with higher resolution. The combination of both electron microscopy methods was suitable for observation of "native" plant samples, allowing correct evaluation of our results, free of error and artifacts.
authors.affiliation: Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic. Electronic address: vilem@isibrno.cz.
authors.forename: Vilém
authors.initials: V
authors.lastname: Neděla
authors.affiliation: Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Hřib
authors.affiliation: Department of Plant Biology, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic.
authors.forename: Ladislav
authors.initials: L
authors.lastname: Havel
authors.affiliation: Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Hudec
authors.affiliation: Environmental Electron Microscopy Group, Institute of Scientific Instruments of the CAS, Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Runštuk
mesh_terms: D003080:Cold Temperature; D020285:Cryoelectron Microscopy / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D009664:Norway; D028222:Picea / Q000196:embryology; D012639:Seeds / Q000648:ultrastructure*
keywords: Bright field/dark field microscopy; Cryo-SEM; ESEM; Extracellular matrix; Picea abies; Somatic embryogenesis