克隆植物中国沙棘生长对外源植物激素的响应

The growth of clonal plant Hippophae rhamnoides L. ssp. sinensis in response to exogenous phytohormone

关于植物克隆生长调节问题,目前集中于外在机制的研究。为了探讨中国沙棘克隆生长调节的内在机制,采用3×3回归设计进行田间试验,期望了解不同生长性状对IAA和CTK用量及其配比的响应规律。结果表明:(1)生长性状对激素用量的响应规律呈典型的钟形曲面模式,即各生长指标均存在一个产量峰值,峰值以前生长指标随IAA、CTK用量的增大而提高,峰值以后生长指标随IAA、CTK用量的增大而下降。(2)不同生长指标对激素用量及其配比的响应规律具有一定差异,较高的IAA比例有利于促进树高生长,较高的CTK比例有利于促进地径和冠幅生长,而几乎相等的IAA和CTK用量有利于种群生物量积累。(3)在激素用量适宜的情况下,中国沙棘生长潜力得到充分发挥,形成高大的个体,较多的子株,有利于提高种群对生境资源的占据和利用,并提高排斥其他植物种类入侵的能力;当激素用量过高或过低时,中国沙棘以降低生长量为代价,形成矮小的个体,减少子株数量,有利于削弱个体之间的竞争。这一结果为了解中国沙棘克隆生长内在调节机制提供了线索。(4)根据不同生长指标的激素效应方程,求出了相应的IAA和CTK的最佳用量和最佳配比,以及合理施激素区域和最低成本线。(5)克隆子株数量增幅与地径和冠幅生长量增幅呈极显著正相关、与种群生物量增幅呈显著正相关,即适宜的IAA和CTK用量既可加速个体生长、也能促进克隆子株的产生。

In order to maintain the stability and persistence of clonal population,clonal plant can make good use of favourable patches or avoid adverse patches by clonal plasticity regulation if the environment conditions are changed.Meanwhile the fitness of population is improved.The adjusting mechanism of clonal plasticity includes external mechanism and internal mechanism.However,researches about clonal plants growth regulation mainly focus on the external mechanism.In order to understand the intrinsic mechanism of clonal growth regulation of Hippophae rhamnoides L.ssp.sinensis,growth and biomass increment in response to Exogenous Phytohormone,IAA in combination with CTK,was studied by 3×3 regression design.The results showed that,（1） the regularity of growth traits in response to the amount of Phytohormone showed the convex surface models.Each growth index has a maximum value.The growth was improved as the increasing of amount of IAA and CTK in front of maximum value,and the growth was decreased as the increasing of amount of IAA and CTK in back of maximum value.（2） The regularities of different growth indexes in response to the amount and ratio of Phytohormone had some differences-the higher amount of IAA was advantage to the height growth of stem,the higher amount of CTK was advantage to the diameter growth and crown width growth,the nearly amount of IAA and CTK beneficial to the accumulation of population biomass.（3） The growth potential of Hippophae rhamnoides L.ssp.sinensis was plenty developed when the amount of Exogenous Phytohormone was feasible.The individuals were tall and the amount of daughter ramet was increased.It was beneficial to not only population improve the lock-in and occupation and utilization to environment resource but also advance the ability of exclude other plants invading.When the amount of Exogenous Phytohormone was too high or too low,the individuals were short and the amount of daughter ramet was reduced to be beneficial to weaken the competition among individuals.This result provided clue to the internal adjusting mechanism of clonal growth.（4）The best amounts and rations of IAA and CTK,reasonable Phytohormones ranges and op-curve lines were gained based on Phytohormone effect equations of different growth index.（5）The increment of daughter ramet was not only significantly related to diameter increment and crown width increment but also highly related to population biomass.It showed the individual growth and daughter ramet generation were accelerated by the feasible amount of IAA and CTK.