Effects Of Waterlogging On Physiological Characteristics And Yield Of Soybean

Soybean is the most main oil-bearing crops cultivated in many place in China, The main stages of southern soybean are often in the rainy season, which are vulnerable to the harm of waterlogging stains. Waterlogging not only affects the phenotypic shape and physiological reactions of soybean, but also affects its production and quality. Therefore, waterlogging has been an important limiting factor to the high and stable yield of soybean. In this study, soybean (Glycine max var. Nannong99-6) was used to study the effect of short and long term waterlogging on the physiological characteristics and yield of soybean seedlings and its inner mechanism, thus providing theoretical basis and technical support for the cultivation of soybean waterlogging resistance. The results were as follows:1. waterlogging stress inhibited the growth of soybean. Biomass, leaf area, chlorophyll content, protein content all decreased significantly, while malonyldialdehyde (MDA), glutathione (GSH), ascorbic acid (AsA) and glutamine synthetase (GS) all increased. Physiological indexes had a certain recovery upon termination of waterlogging stress, and which amplitude was smaller. But these indexes can not be restored to the level of control, especially the recovery capability of soybean reduced with waterlogging stress time developing.2. Through the study of between the seedling stage and the flowering stage, effects of physiological indexes of waterlogging on seedling stage decreased because of the large amount of growth of soybean. At flowering stage, the major of plant nutrient meet the reproductive organs, while the nutritional deficiency of leaves caused by waterlogging can not be replenished timely, which led to be greater of impact on the flowering stage. 3. In sum, physiological indexes had no significant differences as compared with control within10days. The recovery capability of soybean after lifting of flooded10days was stronger than that of20days. Although it can not be regained the level of control in short term, the difference between control and waterlogging10days was smaller than waterlogging20days. So it could be concluded that10d might be the critical time of waterlogging for this soybean cultivar.