Effect Of Branch Bending Angle On Carbon、Nitrogen、Phosphor And Endogenous Polyamines Contents Inshoot Termiani Ofapple

Fuji is the main cultivar in China,while it is more difficult to flower compared with Gala,and also withthe biennial bearing.Branch bending has been indispensable for fruit tree trimming,which could improve the fruit quality and yield,through its ability to suppress theapical dominance,adjust the balance of hormones and promote flowering,In order to explore the relationship between polyamines and apple flower bud differentiation and the effect of branch bending on its content,in the experiment we took Fuji and Gala as test materials to investigate the contents of C,N and P,and meanwhile using high performance liquid chromatography(HPLC),to measure the contents of polyamines in different shoot terminals at different branch angles(0°、70°、90°、110°)in a period and to study the dynamic changes of these substances.The obtained results are as follows:1、Branch bending could obviously increase the flower rate.The contents of carbon and nitrogen in different shoot terminals were higher than phosphorus in the growth period of Fuji and Gala.For Fuji,the contents of carbon and phosphorusraised graduallywith the increase of bending angle,while the nitrogen content decreased,and they all had significant differences among the different treatments.The results in Gala were similar to Fuji,except that there were not much differencebetween 90° and 110°.2、The results we obtained suggested that flowering rate was raised when increased the bending angle.PAs were involved in the flower bud formation and the contents of Put,Spd and Spm in the whole floral bud differentiation all showed an increasing trend,among them Spm was the highest.The contents of endogenous polyamines in ’Gala’ were higher than that of Fuji,which indicated that the level of endogenous polyamines was closely related to the floral ability during the flower bud formation.While the PAs contents of spur were higher than that of medium-long shoot,which may be the results of polyamine synthesis and metabolism,or be related to the demands of different periods in flower fprmation.3、For Fuji,the polyamines contents at 110° were significantly higher than the other treatments,while ’Gala’ was 90°.This phenomenon above demonstrated that there were differences about the effect of branchbending on different cultivars and the polyamines contents within them.These results suggest that there was a relationship between floral bud differentiation and polyamines,and the concentration of PAs was related to cultivar,branch type and bending angle.‘Fuji’ and ‘Gala’ showed an maximum value about the polyamines level under 110°、90°,respectively,at the same time with the highest flowering rate.So we can regulate the polyamines contents in floral formation through it or spraying polyamines to achieve the aims of promoting flowering and increasing the field in production.