Relationship Between Substance Changes And Desiccation Tolerance For Seeds Of Acer Mono And A. Triflorum During Development Process

It was studied of the changes of soluble sugar,faecula,soluble protein,ABA and antioxidative systems(SOD,CAT,POD)in seeds of Acer mono and A.triflorum at developing period.The purpose is to study the changes in material accumulating and desiccation tolerance of the seeds,find the reasonable harvest of seed.We also dry the seeds of A.mono and A. triflorum in natural,to learn the change of material which relate to the desiccation tolerance. The main results were as follows:During the developing of seed,its fresh weight,germination rate and vigour increased rapidly,the storage substance accumulated;the seed after anthesis for 120 days displayed the maximal level.The A.mono seeds after anthesis for 100 days displayed the strongest desiccation tolerance,while the A.triflorum seeds obtained the maximum desiccation tolerance at 120 days after anthesis.The A.mono seeds optimum harvest should be among 100～120 days after anthesis,while the A.triflorum seeds'optimum harvest should be 120 days after anthesis.The seeds of A.mono and A.triflorum among 100-120 days after anthesis,its moisture content decreased;during natural drought of seed,germination rate and vigour index of seeds at diffent developing period showed descendent tendency,the tendency of the activity of peroxidase(POD)was increased and then decreased at the same time,and the change tendency of superoxide dismutase(SOD)and catalase(CAT)was decreased-increasde-decreased,the seeds displayed low desiccation tolerance.The seeds of A.mono and A.triflorum experience mature desiccation,but they didn't obtain enough desiccation tolerance.The experimentation showed that seeds of A.mono and A.triflorum maybe belong to intermediate seeds or low recalcitrant.During the whole development of A.mono and A.triflorum seeds,the content of ABA was low at all time;during natural drought,the content of ABA changeless or decreased. The low content of ABA maybe caused the seeds displayed low desiccation tolerance.