纽荷尔脐橙果肉糖分积累和蔗糖代谢相关酶活性的变化

在纽荷尔脐橙果实不同发育时期测定了果肉中的蔗糖、葡萄糖和果糖含量以及蔗糖代谢相关酶的活性。结果表明:在果实膨大期,可溶性糖积累以蔗糖积累为主,3种可溶性糖含量积累同步上升,果实膨大期结束时是可溶性糖积累的关键时期;在成熟期,3种可溶性糖含量维持膨大期时的最高含量。9月前,果肉蔗糖转化酶(Ivr)活性明显下降,9月后,活性差异不显著;蔗糖磷酸合成酶(SPS)活性在8月最高,然后下降,成熟期又明显上升;蔗糖合成酶(SS)在果实膨大初期和成熟期分解活性高于合成活性,在果实膨大中、后期反之;蔗糖代谢酶类总活性和净活性变化与果实生长发育进程和果肉蔗糖含量的变化特点一致。

Study on the Sugar Accumulation Process of Newhall Navel Orange and Changes of Activities of Sucrose -metabolizing Enzymes

The contents of sucrose, fructose, glucose in flesh and activities of sucrose-metabolizing enzymes in flesh of Newhall navel orange, relationship between sugar accumulation and sucrose-metabolizing enzymes activities were analyzed. It was observed that the accumulative contents of 3 kinds of soluble sugar were increased with the similar rate in the fruit developing process of Newhall navel orange. There existed no remarkable difference in the content of 3 kinds of sugar between the mature period and the late expanding period. The activities of Ivr decreased obviously before September and changed constantly after September. The activity of SPS was the highest in August, and it increased during the mature period again. The change in the cleavage or synthesis activities of SPS and the changes in net activities accorded with the procedures of the growth and development of fruit and the character of change in the content of sucrose in flesh.