【作者】 王彦波；

【导师】 刘慧英；

【作者基本信息】 石河子大学 ， 蔬菜学， 2007， 硕士

【摘要】 西瓜嫁接技术已是当前生产上提高抗性、克服连作障碍、防治枯萎病的一项行之有效的措施。但在嫁接西瓜植株抗性提高的同时,西瓜果实的品质往往有所下降,果实的含糖量有所降低。许多研究已证明GA和ABA能够对植物体内的内源激素水平、糖代谢相关酶以及许多糖代谢相关基因的表达等起到重要的调节作用,从而改善果实内糖的运输和卸载,最终促进果实中的糖分积累。目前,有关GA和ABA对嫁接西瓜果实糖分积累调控机理的研究较少。因此,本试验旨在通过使用不同浓度和种类的外源激素GA和ABA对嫁接西瓜果实进行处理,研究外源GA和ABA对嫁接西瓜果实糖分积累的影响机制,为外源激素在改善果实品质方面提供理论和实践依据。本试验研究结果如下:1.外源赤霉素处理可以提高嫁接西瓜果实内果糖和葡萄糖的含量,降低了蔗糖的含量;外源脱落酸则对这三种糖均有促进效果。在嫁接西瓜果实发育中后期,几种激素处理均促进了果实中可溶性总糖含量的增加,这对果实糖的积累和品质的形成都起到了重要的作用。其中以50 mg/L ABA处理的促进作用最为显著。2.外源赤霉素处理可使嫁接西瓜果实内源赤霉素和脱落酸的含量增加,外源脱落酸处理只能促进内源脱落酸的增加而对内源赤霉素则起到了抑制作用。外源激素作用的不同使果实内源赤霉素和脱落酸的含量和比例也发生了变化,因此对糖的构成和积累效果也发生了变化。3.嫁接西瓜果实糖的代谢过程是由AI、NI、SPS、SS四种糖代谢酶共同作用的结果,外源激素的处理也是通过影响这几种糖代谢酶的活性来起到对果实糖的调控的。其中AI和NI的活性升高有利于蔗糖的分解和果糖和葡萄糖的积累,SPS和SS的活性升高则有利于蔗糖的积累。外源赤霉素处理使嫁接西瓜果实的转化酶的活性提高,而使SPS和SS的活性有所降低。因此使果实中果糖和葡萄糖的含量增加而蔗糖的含量降低了;外源脱落酸则对糖代谢酶AI、NI、SPS、SS的活性都起到了一定的促进效果,所以果实中几种糖的含量都有所增加。更多还原

【Abstract】 Grafting is an important technique to control continuous cropping disturbance and to prevent the occurrence of soil-brane diseases and to increase stress resistance of watermelon plant in china. But, the qualities and sugar contents of grafted watermelon fruit,decreased when resistance of watermelon plant increased. In recent years, Many studies had declared that GA and ABA play important regulative roles on the level of hormones、Sucrose metabolism enzymes and expression of many genes. GA and ABA can improve the transportation and download and accumulation of sugar in fruits of plant. But, the studies on effect of exogenous GA and ABA on sugar accumulation of grafted watermelon fruit,were rare..In the present study ,we investigated the effects of different GA and ABA concentrations on sugar accumulation of grafted watermelon fruits, the main purpose was to clarify the physiological mechanisms of GA and ABA concentrations on sugar accumulation of grafted watermelon fruits and give help to improve the fruit quality of grafted watermelon.The results were showed as follows:Firstly, Exogenous GA can improve the fructose and glucose content of grafted watermelon fruit,but it reduced the sucrose content;Exogenous ABA has advance in these three sugars.It is different between exogenous GA and ABA effect to sugars,but they let the soluble sugar content rised at the middle and latter period of grafted watermelon fruit.It is important to fruit sugar accumulated and quality formed. The treatment of 50ppmABA is best in all.Secondly, Exogenous GA can improve endogenous GA and ABA content of grafted watermelon fruit. Exogenous ABA only increased endogenous ABA content and restrained endogenous GA content of grafted watermelon fruit.The different of exogenous hormone made the content and proportion of endogenous GA and ABA had changed.So the effect of sugar composing and accumulation also had changed.Finally, The sucrose metabolism of grafted watermelon fruits can be adjusted by AI、NI、SPS and SS. The treatment of Exogenous Hormones can effect the activity of sucrose metabolism enzyme,for this the sugars of grafted watermelon fruits can be controlled.The raise of AI and NI activity is beneficial to sucrose analyzed and fructose or glucose accumulated.The raise of SPS and SS activity is beneficial to sucrose accumulated. Exogenous GA can improve Invertase activity of grafted watermelon fruit and restricted the SPS and SS activity.So the fructose or glucose content has increasing and the sucrose has reducing. Exogenous ABA can improve this four Sucrose Metabolism Enzyme activity at all.So the content of these three sugar has increased.更多还原