The effect of flooding on wild rice, Zizania aquatica L.

Abstract

A natural wild rice stand in eastern Manitoba was studied during a normal growing season and a season characterized by major midsummer flooding. Flooding was associated with severe declines in total soluble-carbohydrate content of all organs at the end of the season, and failure to set seed. Total soluble-protein content showed large fluctuations, which were possibly related to protein catabolism. Plants growing at stable, normal water levels showed moderate concentrations of total soluble protein, and soluble-carbohydrate levels increased in all organs during seed production; much of these resources appeared to originate in the aerial leaves. Seasonal soluble-carbohydrate levels of many submerged organs were inversely correlated with water temperature. Air lacunae were greatly expanded in floating and aerial leaves subjected to submersion.