title: Weak static and extremely low frequency magnetic fields affect in vitro pollen germination.
abstract: This study concerns the effects of a weak static magnetic field (MF) at 10 µT oriented downward, combined with a 16-Hz sinusoidal MF (10 µT), on in vitro pollen germination of kiwifruit (Actinidia deliciosa). Extremely low frequency magnetic field (ELF-MF) exposure was carried out by a signal generator unit connected to a copper wire solenoid, inside which samples where placed. Two different kinds of treatment were performed: direct and indirect. In the direct treatment, pollen samples were directly exposed during rehydration, germination, or both. In the indirect treatment, the pollen growth medium was prepared with water aliquots (at standard temperature of 20°C and pH = 6.74) that were exposed before use for 8 or 24 h. The main purpose of our research was to identify a biological marker (in vitro pollen germination in a stressing growth medium without Ca2+) susceptible to the effects of direct or indirect ELF-MF exposure. The working variable was the pollen germination rate, as detected blind after 3 h 30 min by an Axioplan microscope. A directionally consistent recovery of germination percentage was observed both for direct exposure (during germination and both rehydration and germination phases) and water-mediated exposure (with water exposed for 24 h and immediately used). Our results suggest that the ELF-MF treatment might partially remove the inhibitory effect caused by the lack of Ca2+ in the culture medium, inducing a release of internal Ca2+ stored in the secretory vesicles of pollen plasma membrane. Although preliminary, findings seem to indicate the in vitro pollen performance as adequate to study the effects of ELF-MFs on living matter.
authors.affiliation: Department of Agro-Environmental Science and Technology, Faculty of Agriculture, Bologna University, Italy. lucietta.betti@unibo.it
authors.forename: Lucietta
authors.initials: L
authors.lastname: Betti
authors.forename: Grazia
authors.initials: G
authors.lastname: Trebbi
authors.forename: Fabio
authors.initials: F
authors.lastname: Fregola
authors.forename: Michela
authors.initials: M
authors.lastname: Zurla
authors.forename: Pietro
authors.initials: P
authors.lastname: Mesirca
authors.forename: Maurizio
authors.initials: M
authors.lastname: Brizzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Borghini
mesh_terms: D029042:Actinidia / Q000254:growth & development* / Q000648:ultrastructure; D015415:Biomarkers / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D018525:Germination / Q000502:physiology*; D060526:Magnetic Fields; D011058:Pollen / Q000254:growth & development* / Q000648:ultrastructure; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism
chemical_list: D015415:Biomarkers; D014867:Water; D002118:Calcium