Peroxidase Activity in Roots and Leaves of Soybeans1

Abstract

Peroxidase activity in leaves and roots of 24 soybean (Glycine max (L.) Merr.) cultivars was determined 63, 83, and 109 days after planting. Peroxidase activity in soybean leaves increased with each sampling period. The mean activity of all cultivars at 83 and 109 days was 1.8 and 5.4 times greater, respectively, than at 63 days after planting. Peroxidase activity in leaves of most cultivars varied considerably during the season.At 63, 83, and 109 days after planting, peroxidase activity of roots was 17, 7, and 4 times greater, respectively, than in leaves. Activity in soybean roots, as in the leaves, varied considerably with the sampling periods. The mean peroxidase activity in roots was relatively high at 63 days, decreased at 83 days, and increased to 1.2 times the initial activity at 109 days. There was a much greater range between highest and lowest peroxidase activities in both leaves and roots of soybean cultivars at 63 days than at other sampling periods. When peroxidase activity in roots and leaves of five soybean cultivars each in maturity groups II, III, and IV were compared at 63, 83, and 109 days after planting, there was no relation between peroxidase activity and plant maturity.