The Relationship Between Polyamines And Hormones During Apple Flower Bud Physiological Differentiation Period

The Red Fuji apple is the main cultivar in China. Because its shoots grow rapidly, it is difficult for the flower bud to form. This has impact on the quality, yield and therefore profit, and so in order to promote the Red Fuji apple, to solve the problem of differentiation is an urgent matter. The differentiation of the flower bud has a close relationship with the endogenous hormone level, the kind of hormone and the interaction among the hormones, and the balance among hormones can affect the differentiation of the flower bud. The polyamines are a kind of low molecular fatty group nitrogenous base. They have a close relationship with the synthesis, the organ differentiation, the membrane stability and the endogenous hormone balance. They were reported to have various effects on germination, blossoming, fruit set, differentiation of flower bud, sex expression, fruit growth, root system formation and resistance. Therefore to study the intrinsic relationship between polyamines and the hormone is quite important; however, there has been little study done on this relationship during the flower bud physiological differentiation period.In this paper, the changes of endogenous polyamines and endogenous hormones, and the effect of exogenous polyamines and MGBG hormone inhibitors on endogenous polyamines and endogenous hormones were studied with the Red Fuji apple and the Starkrimson during the flower bud physiological differentiation period. The main results are as follows:1. With 10^-310^-6mol/L of exogenous polyamines, it increased the content of endogenous polyamines in the Red Fuji apple and the Starkrimson. Polyamines at 10^-5mol/L had the most obvious effect. For the Red Fuji apple, Spd and Spm treatment had a better effect than Put. For the Starkrimson, Put treatment had the best effect. With 10^-310^-6mol/L of polyamine synthesis inhibitor MGBG, it reduced the content of endogenous polyamines in the Red Fuji apple and the Starkrimson. MGBG at 10^-5mol/L had the most obvious effect.2. In the leaf disk experiment, after 10^-5mol/L of Put treatment, endogenous Put content in the Red Fuji apple achieved the peak in 2 hours, endogenous Spd content achieved the peak in 6 hours, endogenous Spm content achieved the peak in 24 hours. After 10^-5mol/L of Spd treatment, endogenous Put content and Spd content both achieved the peak in 6 hours, but endogenous Spm content achieved the peak in 10 hours. After 10^-5mol/L of Spm treatment, endogenous Put, Spd and Spm contents all achieved the peak in 10 hours. Obviously the exogenous Put increased first the endogenous Put content, then the Spd content and then the Spm. It conforms to the polyamines biosynthesis rule. In the Starkrimson apple, the content change of endogenous polyamines had a similar tendency, only the times were different.3. The leaf disk experiment indicated that, in the Starkrimson apple leaves, GA₃ content and IAA content were lower compared to the Red Fuji apple, and the ZR content and the ABA content were higher than that in the Red Fuji apple leaves. In the Starkrimson apple, the (ABA+ZR)/GA₃ and ZR/GA₃ values were higher than that of the Red Fuji apple. In the Red Fuji apple and the Starkrimson, the GA₃ and the ABA content decreased compared to the control. The ZR and the IAA contents were...