Abstract:To determine the activity of endopeptidease and the degradation of arachin in cotyledons of varying vigour peanut seeds during germination, the new harvested peanut seeds(as seeds of high vigour)were stored under relative humility of 95±1% at 28℃ (as seeds of medium vigour)and 40℃(as seeds of low vigour)for 7 days.After the treatment,the vigour index,endopeptidase activity and rate of arachin degradation were reduced.The isoenzyme of endopeptidase also changed.A new isoenzyme exhibited on PAGE in cotyledons of germinating seed of medium vigour on the 3rd to 6th days,and seeds of low vigour on the 6th day.The results showed that the ability of nutrition supply controlled the seed germination, and the endopeptidase played an important role.It was considered that the aging seed syntheses a new endopeptidase isoenzyme in order to accelerate the arachin degradation during seed germination.
