Response of Maize to Cold Stress During Vegetative Growth1

Abstract

AbstractIn several maize (Zea mays L.) growing regions, sudden, shortterm decreases in temperature may occur when plants are in early vegetative growth stages. Limited research has been reported, however, on the effects of short periods of cold stress during early vegetative stages on subsequent growth and development. Consequently, we studied responses of inbreds A619, B14A, B37, and FR4A to 3/8, 5/10, and 7/12 C night/day temperatures administered for 72 hours at three vegetative growth stages in a growth chamber. Distinct genotypic responses to temperature stress were observed. Seedling growth of B14A was reduced by about 50% by 3/8 and 5/10 C temperatures compared to control plants under constant 10/16 C night/day temperatures. The 3/8 C treatment caused a significant increase in heat units required for B14A to reach the pollen shedding stage of development. These traits were not affected by cold treatments for A619 and B37.A second experiment with B14A, B37, and their single cross hybrid (B14A ✕ B37) was performed with a 72‐hour, 3/8 C temperature treatment imposed at the third‐leaf stage. Treated plants of inbred B14A produced significantly less shoot, root, and total plant dry weight/heat unit than did control plants grown constantly at 10/16 C night/day temperatures. Inbred B37 was not affected by temperature treatments, and the B14A ✕ B37 single cross exhibited a dominant phenotype for tolerance to cold stress. We concluded that maize response to short‐term temperature stress is under genetic control.