根域限制对牡丹花器官碳代谢的影响

Effects of root restriction on carbohydrate metabolism in tree peony floral organs

研究了根域限制(盆栽)对牡丹花器官(花瓣、雄蕊、雌蕊)碳代谢的影响,探索根域限制下牡丹花器官中光合同化物分配和转化酶的变化,为提高盆栽牡丹开花质量、延长花期提供理论和技术支持。结果表明,在根域限制条件下,牡丹花器官出现如下变化:(1)花朵的直径和厚度都显著降低,花器官干质量增加缓慢;(2)花器官之间干质量的分配发生变化,分配到雄蕊的比例增加;(3)花器官总体的蔗糖、己糖含量降低,其中在花瓣和雌蕊中降低程度大,雄蕊中降低程度小;花器官中淀粉含量降低,其中雌蕊中降低最显著。(4)所有花器官中酸性转化酶(Acid Invertase,AI,EC 3.2.1.26)活性显著降低,AI活性的降低使牡丹花瓣、花粉和子房的生长和发育活力都受到影响。因此,根域限制条件下,牡丹花器官库强小,拉动蔗糖输送到花器官的动力不足,蔗糖输送少,蔗糖被利用后,能形成淀粉被存储起来作为储备资源也少,碳水化合物储备资源受限,调动碳水化合物利用的动力不足,以牡丹花径小,开花不良,败育率较高等形式表现出来。

This paper studied the carbon metabolism of tree peony＇ s flower organ （ petal, stamen, pis- til） under root restriction, to explore the photoassimilate partitioning and invertase activity of tree peony under root restriction, aiming to improve flower quality and to extend flowering period. The results showed that, under root restriction, tree peony＇ s flower organ showed the following changes ： 1. The diameter and thickness of tree peony flower were significantly reduced and dry matter increase rate was much lower;2. Dry matter distribution of flower organ changed, which distributed relatively more to stamens; 3. Sucrose content and hexose content of tree peony flower organ were decreased, which reduced much more in petals and pistils than in stamens. The starch content in flower organs were lower than control generally, which reduced much more in stamens; 4. Acid invertase （AI） activities of tree peo- ny flower organ were significantly lower than that of the control, which influenced growth and develop- ment of petal, pollen and ovary. It can be seen that the sink strength of flower organ was not strong enough and have insufficient power to transport sucrose. Sucrose was transported little. When sucrose was used, there was less sucrose to form starch as a reserve resource. There were not enough carbohy- drate and lack of motivation to mobilize carbohydrate to utilize, so the flower diameter was small, with bad flowering and higher abortion rate in tree peony when it was growing under root restriction.