不同温度下卵叶韭更新芽内源激素的动态变化

 运用高效液相色谱法测定了3种不同温度下卵叶韭更新芽内源激素的动态变化。结果表明:(1) 卵叶韭更新芽休眠完全解除必需经过一段时间的冷温处理, 且冷温积累量与休眠解除程度和植株长势呈正相关趋势; (3 ±1) ℃处理不少于92 d可完全解除休眠, 而5～12℃、(20 ±1) ℃处理均不能完全解除休眠。(2) 贮藏31 d后, (3 ±1) ℃和5～12℃处理的GA₃ 和ZT含量上升, ABA含量下降, 其中( 3 ±1) ℃处理的上升和下降幅度更大, 解除休眠所需时间更短; 而(20 ±1) ℃处理在鳞茎干枯腐烂前GA₃ 和ZT含量下降, ABA含量上升, 更新芽不能萌发。(3) 卵叶韭更新芽休眠过程可分为预休眠、真休眠和强制休眠3个阶段, 其中预休眠阶段更新芽的GA₃、ZT、ABA和IAA含量居中; 真休眠阶段更新芽的GA₃ 和ZT含量较低, ABA含量较高, IAA含量较高或居中; 强制休眠阶段更新芽的GA₃、ZT含量达最大值, IAA含量略有增加, ABA含量降至最小值。(4) 卵叶韭更新芽休眠的解除可能主要受控于内源激素GA₃、ABA的含量水平和GA₃ /ABA比值, 当GA₃ / IAA比值大于16.59 ±3.90时, 卵叶韭更新芽的休眠就可能完全解除, 此外ZT也对萌发起着一定的作用。

Dynamic Changes of Endogenous Hormones in Allium ovalifolium Regeneration Buds from Dormancy to Sprouting under Different Temperatures

The changing rules of endogenous hormones in the regeneration buds of Allium ovalifolium during the period from dormancy to sp routing treated with different temperatureswere determined by HPLC. The results indicated that: 1) To relieve dormancy of regeneration buds of A llium ovalifolium required a p roper period of low temperature treatment, and the accumulation of low temperatures showed a positive and marked effect on both the degree of dormancy relieving and the growing performance of the plants. A treatment of ( 3 ±1) ℃ for no less than 92 d could relieve dormancy comp letely but treatments of 5 - 12℃ and (20 ±1) ℃ could not relieve dormancy efficiently. 2) The contents of GA₃ and ZT increased and the contents ofABA decreased after storage of buds at (3 ±1) ℃ and 5 - 12℃ for 31 d, amongwhich the contents of GA₃ , ZT and ABA treated with (3 ±1) ℃ changed remarkably, resulting in a shorter period to relieve dormancy. The dormancy could not be relievedat (20 ±1) ℃ treatment due to the increasing of ABA and the decreasing of GA₃ and ZT contents before its bulb drying rot. 3) The dormancy process of regeneration buds could be divided into three phases as predormancy,real dormancy and forced dormancy. In the period of predormancy, the contents of GA₃ , ZT, ABA and IAA were normal. In the period of real dormancy, the contents of GA₃ and ZT were low, and the contents of IAA were not stable, but the contents of ABA were high. In the period of forced dormancy, the contents of GA₃ and ZT reached the highest and the contents of ABA dropped to the lowestwith a little increase of IAA. 4) Dormancy relieving might be controlled mainly by the contents of GA3 and ABA and the ratios of GA3 to ABA. A ratio of GA₃ /ABA≥16.59 ±3.90 could relieve the dormancy of the regeneration buds completely. More ever, the contents of ZT might also play a certain role in relieving dormancy.