强旱生小灌木绵刺劈裂生长过程中内源激素含量变化的研究

 研究强旱生小灌木绵刺(Potaninia mongolica)劈裂生长过程中内源激素含量的变化。结果表明：1）4种生长状态中，完全劈裂的植株的叶片及劈裂发生部位ABA的含量比其它3种状态的都低，而其根中ABA的含量最大。同其它几种激素相比，ABA在绵刺体内的含量最大；2）劈裂生长发生之前，在劈裂发生部位IAA积累量大，尤其是在即将劈裂的过渡植株的劈裂发生部位IAA含量最大；3）劈裂生长发生过程中GA3含量的变化与IAA的变化有同步性；4）ZR的含量也是在劈裂生长发生前的绵刺的劈裂发生部位中较大，随着劈裂生长的发生，植物从根部向叶片及劈裂发生部位运输的ZR有逐渐降低的趋势，而在劈裂生长发生的过渡阶段，ZR从根部向劈裂发生部位运输的比例较大，分别为19.44%和20%；5）IAA、GA3、ZR 三者协调促进劈裂发生部位细胞的生长和分裂，而ABA的积累对绵刺适应干旱的环境条件起到了一定的调节作用。

CHANGES IN THE ENDOGENOUS PHYTOHORMONE CONTENT OF THE SUPER-XEROPHYTIC SHRUBLET, POTANINIA MONGOLICA,DURING FISSURATE GROWTH

Potaninia mongolica is an archaic, single_species genus plant and is a member of the Rosaceae family. It is well adapted to drought environments. P. mongolica reproduces primarily by vegetative means, but it also can reproduce sexually. This species has two modes of vegetative reproduction: one is that the branches drop and grow new vegetal body and the other is by fissurate growth. Many other xerophilous plants in the Inner Mongolia West Erdos region share the same characteristic of fissurate growth, which is an adaptive strategy to drought environments. Correlated studies of fissurate growth are few, and this is the first report on the changes of the endogenous phytohormone content during fissurate growth. We determined the content of ABA, IAA, GA 3, ZR in tissues of P. mongolica in different states of fissurate growth using ELISA (Enzyme_Linked Immunosorbent Assay), to relate changes of phytohormone content to changes during fissurate growth. The results are as follows: 1) in the four states measured, ABA content was the lowest in the leaf and the fissurate part during the fissurated state and highest in the root. Compared with other endogenous phytohormones, ABA content was the highest. 2) before fissuration, IAA accumulated greatly in the fissurate part, especially during the transitional state, and IAA content was the highest in the fissurate part. 3) during fissurate growth, changes in GA 3 content followed that of the IAA content. 4) ZR content was also the highest in the fissurate part before fissuration. During fissurate growth, ZR content carried from the root to the fissurate part and the leaf decreased gradually, and, during the transitional state, the percent of ZR carried from the root to the fissurate part was higher; these were 19.44% and 20%. 5) IAA, GA 3, and ZR mutually regulated and promoted the growth and splitting of the cells in the fissurate part, and the accumulation of ABA in P. mongolica roots was an adaptive response to its droughty environment.