杨桃新梢花芽分化及其碳水化合物含量的变化

 以6年生盆栽甜杨桃为材料，观察了新梢上各节位芽的分化情况，比较了新梢上不同节位的碳水化合物含量。结果表明：当第2节位开始“露红”（肉眼可辨红色的花芽）时，新梢上各节位上的芽（顶芽除外）基本上进入形态分化阶段。第3和第4节位“露红”的枝条，韧皮部和木质部可溶性糖含量比第1位和第2位“露红”的枝条高。徒长枝第1节位的可溶性糖和淀粉含量都较高，第3、第5节位的含量与第1或第2节位“露红”的成花枝上相应节位的含量相当。本研究结果表明，杨桃新梢上的芽在进行形态分化的过程中，枝条仍在积累碳水化合物。

Flower Bud Differentiation and Changes of Carbohydrate in New Shoots in Averrhoa carambola

Histological differentiation of flower buds in different nodes of new shoots in 6 years old potted Averrhoa carambola was studied. Also carbohydrate contents in these nodes were assayed. The results showed that when the second node of the bud in new shoot became red, buds in this new shoot had almost been in his- tological differentiation stage except for the apical bud. Soluble sugar contents in phloem and xylem in shoots in which the first or the second bud became red were lower than those shoots in which the third or fourth bud became red. Soluble sugar and starch levels in the first node in water shoots were high, and those in the third and fifth nodes were low. The results indicated that new shoots still accumulate carbohydrates when its buds were in histological differentiation stage.