Effect of gibberellin and retardants on the germination of seeds with different types of reserve substances under the conditions of skoto- and photomorphogenesis
Keywords: effect of light, morphogenesis, source-sink system, seed germination, gibberellins, retardants
AbstractThe influence of preparations of phytohormone gibberellin and antigibberellin–retardants tebuconazole and chlormequat chloride – on the germination of plant seeds with different types of reserve compounds in the light (photomorphogenesis) and in the dark (skotomorphogenesis) was studied. It was established that under the action of gibberellin, stimulation of the aboveground part and root system growth of maize, beans and pumpkin seedlings was more intensive in comparison with the control. This process was faster in the dark. The use of tebuconazole and chlormequat chloride significantly inhibited the process of germination both in the light and in the dark. At the same time, the coefficient of the use of reserve substances was maximal under the action of gibberellin, and minimum under the action of retardants, both under the conditions of skoto- and photomorphogenesis. The change in the growth characteristics and the coefficient of the use of reserve substances of bean seeds was accompanied by a decrease in the content of total nitrogen, indicating the use of reserve nitrogen-containing compounds in the processes of morphogenesis. The content of protein nitrogen in the control was lower under the conditions of skotomorphogenesis than in the photomorphic seedlings, and the opposite effect was noted for the actions of gibberellin and the retardant. In the later stages of germination, the largest reserve oil of pumpkin seed remained in cotyledonary leaves of photomorphic plants under the effects of chlormequat chloride, which clearly correlated with the least intense growth rates of seedlings in this variant, both in the light and darkness. Under conditions of skotomorphogenesis the growth stimulating effect of gibberellin significantly increased, and the light blocked the action of this phytohormone.