Effects Of A New Plant Growth Regulator On Soybean Photosynthetic Physiology,Yield And Quality

In the face of growing population pressure,ensuring food supplies is particularly important.Plant growth regulators can regulate the crop growth and increase yield.The aim of the experiment is to study the effects of the new triazole plant growth regulator,CGR3-1,on soybean growth and development,and to provide scientific evidence for the application of regulators in leguminous crops.The study was conducted in 2018 at the National Coarse Cereals Engineering Research Center.Two soybean(Glycinemax(L.)Merr.)cultivars ‘Hefeng50' and ‘kenfeng16' were selected as experimental materials.The study determined the photosynthetic characteristics,yield and fatty acid composition of CGR3-1-treated(1-(3,3-Dimethyl-2-oxybutyl)-1H-1,2,4-triazole-3-carboxylic acid)soybean plants.The main results are as follows:1.Applying CGR3-1 at V3 stage significantly improved the PN of Hefeng 50 at flowing stage(R1)and seed-filling stage(R5),and Kenfeng16 at R1 stage,and increased by 27.68%,21.90% and 97.16%,respectively.The application CGR3-1 at R1 stage had no significant impact on PN,however,an obvious increase in Hefeng50 gs was found at R1 stage.In addition,CGR3-1 markedly improved the performance of Ci for Hefeng50 on DAS91 and for Kenfeng16 at initial seed-filling stage.Spraying CGR3-1 at R5 stage was not significantly affected the gas exchange parameters for Hefeng50 and Kenfeng16.2.CGR3-1 sprayed at Tthird-trifoliolate stage(V3)significantly decreased the accumulation of starch at R6 stage in Hefeng50 and Kenfeng16 leaves,which decreased by 2.03% and 14.11%,respectively.CGR3-1 application at V3 stage significantly increased the sucrose content in Hefeng50 seed while decreased its content in the pod shell.For Kenfeng16 sucrose content,CGR3-1 treatment markedly decreased its content in seed and increased in pod shell.Applying CGR3-1 at R1 stage improved the sucrose content in Hefeng50 leaves,however,reduced the accumulation of starch.A 53.89% reduction was found in seed sucrose content in Hefeng50 CGR3-1 treatment,while the starch content also reduced by 24.21% compared to control group.Kenfeng16 starch content significantly increased in CGR3-1-treated soybean seed at R6 stage,and improved by 47.62%.The application of CGR3-1 dramatically increased the pod shell starch content in Hefeng50,while significantly decreased the pod shell sucrose content in Kenfeng16.The application of CGR3-1 at R5 stage increased the starch content in Hefeng50 and Kenfeng16 leaves at R6 stage.The performances of seed sucrose were different in two CGR3-1-treated soybean cultivars,which increased by 34.59% for Hefeng50 and decreased by 25.49% for Kenfeng16.In addition,CGR3-1 application at R5 stage decreased the pod shell starch content in Kenfeng16 at R6 stage.3.Applying CGR3-1 at V3 stage reduced the soybean hundred-grain weight.The application of CGR3-1 at R1 stage increased the hundred-grain weight,increased the number of pods and grains per plant in Kenfeng16,and its yield increased by 27.62%.The application of CGR3-1 at R5 stage increased the hundred-grain weight for Hefeng50,and increased by 9.98% compared to the control,while reduced by 3.52% in Kenfeng16.CGR3-1 is beneficial for the increase of Hefeng50 seed linoleic acid content when applied at V3 stage.4.CGR3-1 can regulate the biosynthesis of chlorophyll when applied at flowering stage,and the responses of Hefeng50 and Kenfeng16 to CGR3-1 are different.CGR3-1 improve the expression of HEMA(Glyma.04G089800),CHLI(Glyma.07G204300),CHLM(Glyma.05G200500,Glyma.08G007900)for the biosynthesis of chlorophyll in Kenfeng16.Despite the expression of CHLI(Glyma.07G204300)and CHLM(Glyma.05G200500,Glyma.08G007900)are high in Hefeng50,the down-regulation of HEMA(Glyma.04G089800)for the biosynthesis of chlorophyll,and up-regulation of HEMH(Glyma.04G050400)for the biosynthesis of heme.In summary,CGR3-1 can increase crop yield,especially for Kenfeng16 soybean plants when applied at R1 stage.The application of CGR3-1 at R1 stage promoted the biosynthesis of chlorophyll in Kenfeng16,and the soybean plant had good ventilation and light transmission,the received light for whole plant leaves was high,which showed a higher yield compared to treat at V3 and R5 stage.Applying CGR3-1 at V3 stage was beneficial to increase Hefeng50 seeds linoleic acid content.