The effects of permanent magnetic fields on in vitro growth of Phalaenopsis plantlets

Abstract

SummaryThis is the first study to address the effects of permanent magnetic fields (MFs) on the in vitro growth of Phalaenopsis plantlets. Uniform Phalaenopsis Gallant Beau ‘George Vazquez’ plantlets, each with two leaves and two roots, and each approx. 2 cm in height, were excised from a mass of protocorm-like bodies (PLBs) after 3 months of sub-culture. The plantlets (n = 21) were cultured in a film culture system (‘Miracle Pack’®) under MFs of different intensity: 0.10, 0.15, or 0.20 Tesla (T). Each culture vessel at each MF intensity was cultured on the North (N) or South (S) poles of specialised magnets. The 0.15 T MF was also applied for different lengths of time (1, 2, or 3 months) at both the N and S poles. Control plantlets were simply exposed to the naturally-occurring geo-MF, and not to any induced MF. All MFs tested had a positive influence on shoot and root development, but did not influence chlorophyll contents. Among all the intensities and polarities of MF tested, 0.10 T – S had the greatest positive influence on specific growth parameters of Phalaenopsis plantlets such as maximum leaf length, root length, fresh weight and dry weight of shoots and roots, and leaf width. Constant exposure to a MF of 0.15 T for 3 months, at either the N or S poles, significantly enhanced the development of plantlets.The results obtained in this study indicate that MFs can have a positive effect on the efficiency and quality of clonal Phalaenopsis plantlets during commercial production. The MFs from commercially-produced permanent magnets enhanced Phalaenopsis plantlet growth significantly and can be used as a novel means to study the effect of MFs on plant growth and development, or to control morphogenesis in limited spaces such as space stations.