Effects of magnetized water treatment on growth characteristics and ion absorption, transportation, and distribution inPopulus×euramericana‘Neva’ under NaCl stress

Abstract

The effects of magnetized water irrigation on the growth and ionic movements of one-year-old potted seedlings of Populus × euramericana ‘Neva’ were investigated. A magnetic treatment device was used to treat the plants. The contents of K+, Na+, Ca2+, and Mg2+in leaves and roots were analyzed by atomic absorption spectrophotometry (AAS), and the fluxes of K+, Na+, Ca2+, Mg2+, and H+in mesophyll cells and in meristematic zones were measured using a noninvasive micro-test technique (NIMT) after 30 days of treatment. After 90 days, the plants were harvested, and their growth indices and root morphology were measured. The results showed that (i) compared with nonmagnetic treatments (NMT), the magnetic treatments (MT) led to higher K+and Mg2+contents and lower Ca2+content in roots and leaves, while the Na+content was lower and the K+/Na+ratio was higher; (ii) MT enhanced Na+efflux, increased H+influx, and decreased K+and Mg2+efflux compared with NMT; (iii) MT resulted in greater height, diameter, and leaf area of the plants and increased the length, surface area, and number of root tips compared with NMT; and (iv) stomatal conductance (Gs), net photosynthetic rate (Pn), intercellular CO2concentration (Ci), and water use efficiency (WUE) were increased in MT, whereas both transpiration rate (Tr) and stomatal limiting value (Ls) were decreased compared with NMT. The results indicate that the use of magnetized water can promote plant quality and regulate the ion absorption, transpiration, and distribution. Thus, MT is conducive to the re-establishment of ionic homeostatic mechanisms via ion-selective absorption and transportation under salt stress.