国庆1号温州蜜柑转化酶和糖分积累特性研究

Characteristics of Sugar Accumulation and Invertase Activity in Citrus unshiu Marc Var. Guoqing No.1

研究了国庆1号温州蜜柑叶片、果皮和果肉中的蔗糖和还原糖含量,以及酸性转化酶(AI)和中性转化酶(NI)的活性变化,结果表明:(1)果肉中的蔗糖和还原糖随着果实的发育而积累增加;果皮和叶片中的还原糖和蔗糖在整个果实发育阶段积累较少.(2)转化酶活性表现出组织特异性,其中果肉中的酸性转化酶活性随着糖分积累而下降,中性转化酶活性基本保持在一个稳定水平;果皮中的转化酶(AI和NI)活性随着果实发育而上升,随后酸性转化酶活性在8月份以后开始快速下降,到果实成熟时都保持在较低水平,中性转化酶在7月中旬就开始缓慢下降,随后也保持在较低水平;叶片中酸性转化酶活性在6～8月份较低,而此时中性转化酶活性却处在较高水平,在8～10月酸性转化酶的活性则快速升高,并保持在较高水平,而中性转化酶活性却逐渐降低,然后保持在较低水平.另外通过分析转化酶活性和糖分关系表明,国庆1号温州蜜柑果肉中的酸性转化酶与果实快速生长和成熟期糖分积累有着重要的关系.

Sugar contents and invertase activity including acid invertase (AI) and neutral invertase (NI) in leaf, peel and pulp of Citrus unshiu Marc Var. Guoqing No.1 were analyzed respectively. Sugars including sucrose and reduced sugar accumulated with the development of fruit, but those in peel and leaf had little accumulation. The AI activity in pulp declined continuously as sugar accumulation, and the NI activity almost kept constant level. The AI and NI activity in peel gradually increased at the beginning stage of fruit development, and then decreased after Aug. and the middle of July respectively to a lower level. The AI in leaf showed a higher activity than the NI from June to August, and a lower activity from August to October. Analyses of the relationship between invertase activity and sugar accumulation showed that the AI in pulp of Citrus unshiu Marc. Var. Guoqing No.1 plays a pivotal role in the tissue enlargement and sugar accumulation during the fruit maturation.