Effects On Yield Physiological Characters Of Soybean And Seed Submicroscopic Structure Under Plant Growth Regulators

Soybean is important foodstuff crops and economic crops in the world,and it has high nutritional value.Thus it is great significance that yield of soybean and quality of grain were improved through control technology.In this study,we chose Dongnong 46 as the experimental material,and we used four kinds of plant growth regulators(TIBA,RE,SBS and DTA-6)to spray its leaf at different growth and development stages.We studied the effect of the four regulators on the development of soybean grain from the yield traits of soybean plants as well as physiological feature and submicroscopic structure of seed.The experimental results are as follows:1 The impact of the regulators on the yield traits of soybean plants:the soybean plants sprayed by four kinds of regulators all increased pods per plant,seeds per plant and seed weight per plant.But the soybean plants sprayed by TIBA was stunted obviously,reducing the bottom pot height and plant height while3-seed pods and 2-seed pods per plant was much more than those of the control.However,the hundred-seed weight was decreased slightly,indicating that the accumulation of dry matter was decreased.At the same time,RE,SBS and DTA-6 increased hundred-seed weight,and SBS had specially obvious effect on hundred-seed weight,indicating SBS had a significant role in increasing the material accumulation of storage cells.DTA-6 increased seeds per plant and seed weight per plant notably.Generally speaking,the four regulators all increased the yield of soybean,reaching significant difference,while DTA-6 had the best effect(increased by 21.83%).2 The impact of the regulators on physiological feature of soybean seed:through determining photosynthetic rate and chlorophyll content of soybean leaf and content of protein,fat,soluble sugar and starch of soybean seed,we found that SBS could improve the photosynthetic rate and chlorophyll content of soybean leaf obviously,higher than the CK at R1 and R2 stage.Likely,DTA-6 has a certain influence on increasing the photosynthetic rate and chlorophyll content of the leaf.RE was the one which produced the greatest impact on the content of protein and fat of seed at R6 stage,and DTA-6 was the second one,while SBS showed a negative correlation with the content of fat,which was lower than that of CK,during this period.At R7 stage,RE was still the best one improving the content of protein and fat of seed,while DTA-6 improved protein content obviously and TIBA enhanced rapid growth of fat content.At R8 stage,SBS could promote the increase of protein content,resulting in the maximum of protein content of seed,however,the fat content was not improved significantly,compared to that of CK.In addition,RE increased both the protein content and the fat content obviously.Thus,the effect of the four treatments on the protein content of seed at R8 stage from high to low was SBS>RE>DTA-6>TIBA>CK.For fat content,it was RE>TIBA>DTA-6>SBS>CK.The analysis of the content of starch and soluble sugar of the soybean seed at three development stages,R6 and R7 showed that SBS generated the greatest impact on the increase of starch and soluble sugar content which was much higher than that of CK,and DTA-6 was the next one.However,TIBA and RE made the starch and soluble sugar content of seed lower than that of CK.At R8 stage,the soluble sugar and starch content of seed of plant treated by TIBA,RE or SBS was lower than that of CK,the treatment of DTA-6 was higher than that of CK,indicating that TIBA,RE or SBS may speed up the metabolism of the soluble sugar and starch and thus played a promotion role on the growth and development of seed,however DTA-6 could slow the grain growth and development and further resulted in the extension of growth period.3 The impact of the regulators on the submicroscopic structure of soybean seed:using transmission electron microscope(TEM)and scanning electron microscope(SEM),the submicroscopic structure observation on storage cells of seed from four treatments found that,at R6 stage TIBA had a role in the aggregation of protein bodies,and SBS made the shape of protein bodies irregular while RE and DTA-6 increased the number of protein bodies and lipid bodies obviously.At R7 stage,TIBA had a slight impact on the aggregation of protein bodies,but increased the number of lipid bodies which arranged more closely.There were still many protein bodies and lipid bodies in storage cells under RE treatment.while many starch granules and protein bodies under SBS treatment.DTA-6 had a certain role in increasing of protein bodies,the unevenness of shape and size of protein bodies,it made the average diameter of protein bodies larger than that of CK.At Rg stage,storage cells were rich in various substances and protein bodies were large.Storage cells under treatment of RE SBS or DTA-6 had more protein bodies,and RE promoted protein bodies to arrange more closely while DTA-6 led to larger protein bodies,there were still some starch granules unconverted in the storage cells under treatment of DTA-6,indicating that DTA-6 slowed the degradation or conversion of the starch granules.The lipid bodies arranged loosely in storage cells under treatment of SBS,but closely and fully under treatment of RE or TIBA.