Changes in Endogenous Polyamine Contents During Fruit Development of Litchi (Litchi chinensis)

Putrescine (Put), spermidine (Spd) and spermine (Spm) contents in the pericarp, seed and aril ofHuaizhi litchi (Litchi chinensis Sonn.) were analysed during fruit development. The results showed that Spdlevel was the highest among the three polyamines in fruit, followed by Put and Spm. The contents of threepolyamines peaked at 7 and 28 days after anthesis (DAA). The total endogenous polyamine contents in differentfruit tissues were highest at their initial growth stage, then decreased steeply, and kept a stable level during stageⅡ-b (56~70 DAA). In contrast, the contents of the three polyamines on per fruit basis were all the lowestduring 0~21 DAA, and then exhibited a small peak at 28 DAA. But during fruit rapid growth, Spd contentincreased abruptly, while Put and Spm levels rose slowly.