Influence of boron concentrations on some meta‐bolites of date palm and sorghum seedlings

Abstract

Date palm (Phoenix dactylifera L. cv Khedhri) and sorghum (sorghum Sudan grass hybrid cv sugar Graze 11) plants were grown in vermiculite in a controlled environment and watered with a nutrient solution containing eight different concentrations of boron (B) (0 to 500 ppm), six months for date palm and four weeks for sorghum. The chlorophyll (Chl) content of the seedlings increased significantly with low concentrations of B for both date palm and sorghum, but no further significant increases were observed at higher concentrations. Generally, there was a positive correlation between B and calcium (Ca) content in the tissues of both seedlings when B concentrations were increased in the media. A negative correlation was found between B concentration in the media and the tissue content of phenolic compounds and the activity of some enzymes, such as polyphenol oxidase, IAA‐oxidase and phenylalanine ammonia‐lyase in the tissue, while there was a positive correlation in the case of peroxidase. Ribonucleic acid (RNA) increased significantly in date palm with the increase of B in the medium, but for sorghum, the increase occurred at 10–100 ppm and decreased at 300 and 500 ppm B in the media.