Effects of Exogenous Strigolactone on Wheat Grain Filling and Yield Formation in Different Cultivation Densities

Abstract

Wheat is one of the main crops in northern China, and drought has been a major problem in wheat cultivation. As a new type of plant hormone, Strigolactone (SLs), its effect on drought resistance of wheat needs to be studied extensively. In this study, the effects of SLs on the growth and development of wheat from florescence stage to maturity stage were determined by plant physiological and enzyme-linked immunoassay techniques. The results showed that, with the progress of reproductive development, leaf spraying exogenous SLs not only delayed the peak of ABA content, promoted the increase of IAA and GA content in the early stage, changed the metabolic balance of hormone in leaves, and thus changed the physiological metabolic process. Especially under the condition of high density, the effects of SLs were more obvious. And, with the change of the blade metabolic balance, its net photosynthetic rate and the level of carbon dioxide fixation increased, and SOD and POD activity enhanced, MDA content decreased, indicating that aging rate of leaves was slowed down and matter accumulation ability enhanced, so as to improve the filling rate and increase the weight of the mature grain, eventually promoted the yield of wheat. Through the above analysis, it can be seen that exogenous SLs can effectively improve the yield of wheat under high density condition, which provides reliable theoretical and technical support for its practical application in the field.