Standardization of in vivo nitrate reductase activity and its pattern in the individual leaf blades of Myrica esculenta Buch. Ham. ex. D. Don

The pattern of in vivo nitrate reductase (NR) activity in the individual leaf blades of Myrica esculenta was studied under 0.2 M phosphate buffer solutions with pH ranging from 6.8 to 8.4 and concentrations of substrate solutions KNO3 varying from 0.025, 0.050, 0.10, 0.20 and 0.25 M. Phosphate buffer 0.10 M solutions of pH ranging from 6.0 to 8.4 were also tested with the 0.10, 0.15 and 0.20 substrate (KNO3) concentrations. Highest NR activity was observed with 0.10 M buffer concentration, pH 8.0, and substrate (KNO3) concentration 0.10 M. Among different leaf blades from top to bottom, NR activity increased up to 8th leaf position, and afterwards it decreased. Fresh and dry weight was higher between 6th–9th leaves. However, moisture content remained between 30 and 40 % in all the leaves. © 2014, Indian Society for Plant Physiology.