荔枝树成花与碳水化合物器官分布的关系研究

 选择荔枝不同末端梢抽生期的植株, 于成花诱导期间取样分析, 比较了高成花树与低成花树可溶性糖和淀粉含量的变化。‘桂味’荔枝末端秋梢抽生早的树(10 月5 日抽梢) 成花枝率为95.8% , 而抽生晚的树(11月15 日抽梢) 为18.0% ,‘妃子笑’荔枝10月1日抽梢树和‘糯米糍’荔枝两个抽梢期树(10 月15 日和11 月5 日) 的成花枝率均在99%以上。从11月中旬到1月中旬, 各器官可溶性糖含量一般先上升而后下降; 淀粉含量则不同程度地提高。低温来临前各器官淀粉含量差异不大, 到花发端之前, 3个品种高成花率树的淀粉含量以小枝(粗度1 cm) 为最高, 形成从小枝到末端秋梢和叶片的下降梯度, 而低成花率的桂味荔枝树的淀粉含量则未见这种梯度。认为这种淀粉含量分布可能是荔枝枝梢接受成花诱导、反映诱花效果的一个标志。

Flower Formation and Patterns of Carbohydrate Distribution in Litchi Trees

The study aimed to investigate the carbohydrate changes during flower induction of litchi (Litchichinensis Sonn. ) trees. In‘Guiwei’litchi, 95.8% terminal shoots flowered on trees of early (Oct.5) terminal flushing whereas only 18.0 % on trees of late (Nov.15) flushing. Over 99 % of terminal shoots in ‘Nuomici’and‘Feizixiao’litchi trees , irrespective of flushing early or late (from Oct.1 to Nov.5) , formed flower panicles. The contents of soluble sugars and starch in roots (1 cm in diameter) , trunks (5-8 cm in diameter) , large branches (3-5 cm in diameter) , small branches (1 cm in diameter) , terminal autumnal shoots and leaves were investigated over the period from November to January. Results showed that the concentration of soluble sugars increased from November to December and then decreased in January, while the starch concentration increased progressively , especially in the upper parts of the canopy. Starch concentrations in the heavy flowering trees were highest in small branches and decreased acropetally and basipetally , whereas the concentrations of soluble sugars were highest in the terminal shoots. Starch concentration in the leaves was higher than that in the terminal shoots of the light flowering trees. It is suggested that carbohydrate distribution pattern may serve as an indication for the judging of the floral induction effect in litchi .