Nitrogen uptake during the leafless period in juvenile plants of a winter-green perennial herb, Lycoris radiata var. radiata (Amaryllidaceae)

Abstract

Leafless plants are often assumed to be in a dormant stage with low physiological activity. However, having an ability to take up nutrients during the leafless period may be beneficial if nutrient availability is high during that period. We examined a winter-green geophyte, Lycoris radiata var. radiata, to determine whether it maintained root activity during the leafless period for this species (from June to September in central Japan). The species had roots throughout the year, but new roots emerged mainly during the leafless period. The new roots took up applied nitrogen during the leafless period. The annual maximum rate of root respiration occurred in July. These results suggest that the leafless period is not a dormant period for L. radiata var. radiata; instead, it is a period with high root activity.