Research Of Source Regulation On Substance Production And Grain Nutrition Components Accumulation Of Transplanted Maize

In order to realize the double cropping pattern of grain crops in one year and improve the utilization efficiency of light,temperature and water in Liaoning Province,it is a feasible way to plant transplanted maize.It found that in order to increase yield,planting density was often increased during transplanting.However,the increase of maize density will cause inconsistency between source and sink.Source regulation can improve this situation during transplanting.With maize variety Liaodan 566 as material,planting density was83375hm-2 in the experimental base of Shenyang Agricultural University.Before seedling transplantation,different degrees of leaf cutting or root cutting(source reduction)were carried out,including 15% leaf cutting(L3),30% leaf cutting(L4),root cutting(L5),15% leaf cutting and rooting(L6)and 30% leaf cutting and rooting(L7).Direct seeding maize without source reduction was used as control 1(L1),and transplanted maize without source reduction was used as control 2(L2).It was studied that the effect of source reduction of agronomic characters,photosynthesis characteristic,dry matter production,accumulation and transport,grain develop and yield and quality of transplanted maize.The following results were obtained:1.All source reduction treatments reduced the plant height of transplanted maize,and the treatment of 15% cutting leaves and roots was significant(p<0.05).Reducing plant height can reduce the center of gravity of the plant and effectively prevent lodging.Leaf removal by 15% and 30% can effectively increase plant stem diameter,but removal of root causes leads to insufficient nutritional supply of roots at early stage of development,resulting in a significant reduction in plant stem diameter.Reducing leaf or root sources alone had no significant effect on ear height and ear height coefficient of transplanted maize,while removal of leaf and root sources together significantly(p<0.05)reduced panicle height and panicle height coefficient.2.Removal of 15% leaf source slowed down LAI decline,and maintained a high SPAD and Pn at later growth stage,delayed leaf senescence and prolonged the duration of dry matter accumulation in grains.Removal of leaf and root sources together lead to lower LAI,rapidly SPAD decreased and significantly(p<0.05)reduced Pn in the later growth stage.Therefore,the material production capacity was weakened and the senescence of ear leaf was accelerated.3.Removal of 15% leaf source increased dry matter accumulation after silking,accelerating the stem dry matter transfer of maize in the later growth stage.The maximum grouting rate and growth at the maximum grouting rate during the grouting period were significantly increased(p<0.05).Thus,grain weight increased significantly(p<0.05),which resulted in a significant(p<0.05)increase in yield at maturity.Removal of leaf and root sources together due to reduce excessive source resulted in more dry matter remaining in the stem and decreased assimilate accumulation,moreover,the accumulation of assimilates decreased,resulting in a significant(p<0.05)decrease in total dry matter weight at maturity.It also delayed the days when the maximum grouting rate was reached,and reduced the growth at the maximum grouting rate and the maximum grouting rate.As a result,the dry weight of grains at maturity stage was lower and the yield decreased significantly.4.Different effects of source alteration on grain starch,protein,total amino acids and oil concentration could be found.After reducing the source of transplanted maize,it was found that the grain oil content was not affected by the change of source-sink relationship,and there was no significant change.In addition to oil content,protein content and total amino acid content reached the maximum when the leaf source was reduced by 15% after transplanting at seedling stage.Removal of leaf and root causes significantly reduced(p<0.05)the percentage of protein in grains.The percentage of starch showed the opposite trend with the percentage of protein and total amino acid,and reached the maximum when the leaf and root sources were reduced by 15% after transplanting at seedling stage.