钾对水稻籽粒发育中激素变化的影响

EFFECTS OF POTASSIUM ON THE VARIATION OF HORMONES IN DEVELOPING HYBRID RICE SEEDS

在水稻籽粒成熟过程中,CTK、IAA、GA和ABA依次出现。其中,CTK的升降与初生胚和胚乳形成的时间基本吻合,ABA的高峰期与籽粒进入腊熟期的时间完全一致,说明籽粒的发育与成熟受内源激素的调节。钾显著降低了空壳率,可能是提高了CTK的含量,使受精卵的退化率降低;推迟了ABA出现的高峰期,使灌浆期延长,转移到籽粒中的碳水化合物增多,因而粒重加大。

A pot-experiment was conducted to study the relationship between potassium nutrient and hormones in developing hybrid riee seeds in an acidie purplish soil (pH 5.41 available potassium 2.41μm g^(-1), total potassium 10.2g Kg^(-1)). Three treatments were employed 1. check (K_0); 2. K_1(0.05g KCl/Kg soil), 3. K_2(0.25g KCl/Kg soil). It was found that the sequence of hormone appearance in the seeds were CTK, IAA, GA and ABA. The zygote development coincided with the CTK appearance and disappearance, while the peak of ABA seemed synchronized with seed maturation. It suggests that seed development and maturation is controlled by hormones. Furthermore, potassium remarkably decreased the rate of unfilled grains. The reason for this may be that potassium promoted CTK synthesis, which resulted in less zygote degeneration, while potassium enhanced grain weight because the peak of ABA was prolonged for 4 to 5 days, whereby the maturation was postponed and carbohydrate transeolation to seeds was increased.