Comparison between the Influences of Silver Nanoparticles and Silver Nitrate on the Growth and Phytochemical Properties of Borage (Borago officinalis L.)

Abstract

Climate is likely to render a number of physiological responses in plants affecting various phytohormones, such as ethylene which influences the growth and phytochemical properties of plants. Certain compounds are found to be effective in alleviating the ef- fects of ethylene e.g. silver nitrate, which saves the plants from the hazardous effects of ethylene and helps in modifying their growth and metabolism. Silver nanoparticles are considered as novel silver compounds that were developed with the help of nanotechnology. In a re- cent study, the foliar application of silver nanoparticles and silver nitrate during seed growth has been reported to minimize the rate of seed abscission and to maximize the seed yield of borage. The study has therefore been aimed to find out the comparison between the ef- fects of the foliar application of silver nanoparticles and silver nitrate on the vegetative and phytochemical properties of borage. Different concentrations of silver nitrate (0, 10, 20, and 30 mM) and silver nanoparticles (0, 0.2, 0.4, and 0.6 mM) were taken into considerations for finding out their efficacy; the aerial parts of borage plants were sprayed with these solutions at the onset of the flowering stage (65 days after cultivation) and were maintained un till flowering (98 days after cultivation). These solutions were reported to significantly en- hance the vegetative (leaf number, greenness of leaves, plant dry weight, inflorescence dry weight, and petal abscission) and phytochemi- cal (phenol, tannin and alkaloid content, mucilage percentage and swelling index) properties of borage. A stronger beneficial effect was observed with 0.6 mM concentrationof silver nanoparticles than the ones with other treatments regarding the maximization of the meas- ured properties of borage.