砧木对柑桔嫁接幼树早果影响的生理生化研究

本文研究了枳和红桔两种砧木对柑桔嫁接幼树结果早晚影响的生理生化差异。1.枳砧树较红桔树至少提早二年开花,枳砧树的单叶面积、株高、新梢生长量和干径均小于红桔砧树;2.花芽生理分化期枳砧树叶片的可溶性糖、淀粉及还原糖的含量均高于红桔砧树,叶片总氮含量变化不大,但在花芽形态分化期,砧木对叶片可溶性蛋白质含量的影响较大。叶片C/N比值与花芽形成存在一定相关关系。10月上中旬各因子二种砧木树的相对含量有一明显逆转过程,3.花芽生理分化期枳砧树叶片内源玉米素和脱落酸含量高于红桔砧树,赤霉素(GA_3)低于红桔砧树,整个试验期间,Z/GA_3和ABA/GA_3比值均为枳砧树高于红桔砧树。

PHYSIOLOGICAL AND BIOCHEMICAL STUDIES ON THE ROOTSTOCK EFFECTS ON EARLY BEARING OF GRAFTED CITRUS CULTIVARS

In this research, the physiological and biochemical differences of the early bearing effects of trifoliate orange and Hongju rootstocks were studied during the period of flower bud differentiation. Experimental results are summerized as follows:1. Jincheng and Bonanza Navel orange trees on trifoliate orange rootstock could flower two years earlier than those on Hongju rootstock. The single leaf area, height, shoot growth, and trunk diameter of trees on trifoliate orange rootstock were all smaller than those on Hongju rootstock. This suggested that there was a certain negative correlation between early bearing and growth vigor,2. During the physiological differentiation stage of flower bud, the level of soluble sugar, starch and reducing sugar of scion leaves for trees on trifoliate orange rootstock were all higher than those on Hongju rootstock. The certain differences of the contents of nitrogen and soluble protein for trees on two rootstocks were found at the later stage. There were certain relationships between the C/N ratio and the flower-bud differentiation as well as the amount of flowers. About the end of September and the early October, there was an outstanding inverted trend for the related contents of nutrients in two rootstocks. This meant that the distribution of nutrients among the various parts of plant wound play a important role in flower bud differentiation and early flowering.3. During the flower-bud differentiation period, the contents of endogenous zeatin and ABA in leaves of trees on trifoliate orange root-stock were significantly higher than those on Hongju rootstock , but GA3 was significantly lower. This indicated that zeatin and ABA pro-moted and GA3 inhibited flower bud differentiation. The cause of early flowering of trees on trifoliate orange rootstock might be that: the growth point got more ABA and zeatin, less GA3; the changes of hor-mone balance could therefore initiate flower bud differentiation.