Effects Of Ddtc Sparyed After Waterlogging At Seedling Stage On Growth And Physiological Characteristics Of Soybean

Soybean is an important economic and raise land crop that would be subject to waterlogging in its growing season because of the concentrated rainfall in southern area. Therefore, taking appropriate measures to mitigate the waterlogging of soybean and improving recovery capabilities is significant. In this study, one pot experiment was taken that soybean (Glycine max var. Nannong99-6) and diethyldithiocarbamate (DDTC) was used to study the effects of DDTC on growth and physiological characteristics of soybean after different days of waterlogging at seedling stage, and in order to make a further explore, another pot experiment was conducted with two soybean varieties of Nannong99-6and Nannong1138-2(Glycine max var. Nannong1138-2), which provided theoretical basis of soybean waterlogging resistance and disaster reduction. The results were as follows:1.Waterlogging stress inhibited the growth of soybean that plant height, biomass, and root shoot ratio significantly decreased with prolonged stress, it could hardly achieve the normal level though the recovery after removing waterlogging stress, which finally resulted in a significant decreasing of the number of pods, pod weight, grains and yield per plant. The yield decreased more significantly with a harder recovery as waterlogging stress time lasted, in which the reduction of multi-seed pods was the most obvious. It would accelerate recovery spraying DDTC on soybean after stress removed that ultimately lower the range of yield decreasing, in which the increase of multi-seed pods was more important. The shorter the stress time lasted, the more obvious the spraying effect would be.2.With the deepening of waterlogging stress level, MDA and H2O2contents and the rate of O2·-production increased significantly, the same as SOD activity and HAsA and GSH contents while opposite the chlorophyll content, and the recovery ability of waterlogged soybean deceased after stress removed. However, it was DDTC which was sprayed after stress removed that inhibited SOD activity and decreased GSH content while increased HAsA content, so that O2·-, H2O2and MDA level obviously decreased that ultimately improved the recovery activity of waterlogged soybean. Though the recovery was slower with the longer stress time, the spraying effect would be more obvious.3. Waterlogging inhibited the growth of soybean that the levels of SOD, POD, HAsA and GSH all significantly improved in both of the two soybean varieties, in which the waterlogging tolerant variety Nannong99-6had a higher antioxidant ability so that it could maintain lower reactive oxygen species (ROS) and MDA levels, and also higher antioxidant ability after stress removed that made it have a quick recovery, which ultimately made the range of yield reduction lower than waterlogging sensitive variety. DDTC treatment inhibited SOD activity and decreased GSH content, and could induce the increasing of POD activity and HAsA content of the two soybeans, thus slowing down the decrease of antioxidant ability and maintaining a higher ROS scavenging ability after removing the stress to make O2·-, H2O2and MDA levels decreased rapidly, in which the waterlogging tolerant variety Nannong99-6was particularly evident, and ultimately reduced the yield cut, in which the sensitive variety Nannong1138-2had more apparent effect.