Studies On The Relationships Between Polyamine Metabolism And Compatibility Of Rootstock-scion And Flower-fruit Development In Persimmon

Sweet persimmon 'Taishuu',astringent persimmon 'Xiaofangshi',persimmon rootstock 'D.lotus L.',Diospyros kaki Thunb.var.silvestris Mak of 'Dabieshanyeshi'and 'Yizhengyeshi'were used as experimental materials in this article.The relationships between the persimmon'Taishuu' graft compatibility of persimmon stock and scion and endogenous polyamine metabolism were investigated.The relationships between the development of persimmon fruits and calyxes and polyamine metabolism in 'Taishuu" and 'Xiaofangshi' were analyzed.The effects of polyamine on flower buds development and polyamine metabolism in Taishuu' were discussed.The main results were as follows:1.In the compatibility combination of persimmon stock and scion,young leaves of the rootstocks contained the free polyamine cadaverine(Cad)and the mature leaves of rootstocks contained the bound polyamine Cad,furthermore,the bound polyamine spermine(Spm)content in the young leaves of the rootstock was significantly higher than that of the scion,and the bound polyamine putrescine(Put)content in the mature leaves of the rootstock was significantly higher than that of the scion also.The difference of the free polyamines Put and spermidine(Spd)contents of the mature leaves in the compatible combinations of stock and scion were less than the incompatibility.The research can provide experimental basis for constructing biochemical indicators for the early screening of sweet persimmon.2.The contents of free polyamines Spd and Spm in sweet persimmon fruits were significantly higher than that in astringent persimmon 10 days after full bloom.On the contrary,the contents of free polyamine Put,bound polyamines Put,Spd and Spm in sweet persimmon fruits were significantly lower than that in astringent persimmon.There were four kinds of free polyamines Put,Spd,Spm,Hex and five kinds of bound polyamines Put,Spd,Spm,Hex,Cad.3.Calyxes removal could apparently reduce the contents of bound polyamines Put,Spd,Cad in fruits and inhibit the fruit growth,which indicated that calyxes could regulate the metabolism of polyamines in fruits,and bound polyamine Cad might be the key polyamines to produce this regulation.4.Spd and Put treatment could apparently increase the contents of free polyamines Put,Spd,Spm and Hex in fruits,reduce the contents of bound polyamines Put,Spd,Spm,Hex,Cad and improve the fruit growth,which indicated that exogenous Spd and Put could increase the synthesis of free polyamines and inhibite the synthesis of bound polyamines in persimmon fruits.5.The changes of high levels of the free polyamines Put and Hex and bound polyamines Put,Spd,Spm,Cad and Hex were the characteristics of polyamine metabolism in male flower bud differentiation,although the detection of free polyamine Cad content,and the high level of free polyamine Spm content were the characteristics of polyamine metabolism in female flower bud differentiation of sweet persimmon.6.The exogenous treatment with 100 ppm polyamine Spd could significantly increase the contents of free and bound polyamines Put,Spd in male flower buds,which inhibited the synthesis of bound polyamines Spm,Cad and Hex in male flower buds.The exogenous treatment with 50 ppm polyamine Put could considerably increase the free and bound polyamine Put in male flower buds,which inhibited the synthesis of the free polyamines Spd,Spm and Hex and the bound polyamines Spm,Cad in the male flower buds.