Effects of High Temperature and Growth Retardant on Dry Matter Accumulation, Hypocotyl Thickening, Photosynthesis, and Sugar Content in Radish (Raphanus sativus L.) Plants

摘要

Radial thickening of radish hypocotyls is inhibited by high temperature, but the inhibition is reversed by the application of growth retardants. To study these phenomena, dry weight accumulation, net photosynthesis (Pn), and sugar contents of developing plants were determined. These results showed that photosynthetic ability of leaves and glucose and fructose contents decreased in the hypocotyls of plants grown at an elevated temperature. Growth parameters for quantitative growth were unaffected by the high temperature, whereas reducing sugar content was slightly increased by the application of the growth retardant uniconazole P. These results indicate that the growth retardant affected the process of reducing sugar accumulation, but not Pn directly.