脱落酸对中国沙棘克隆生长调控机制的研究

目前，关于中国沙棘克隆生长调节的研究集中于外在机制。为探讨脱落酸在中国沙棘克隆生长调节过程中的作用机制，通过灌水强度形成土壤水分梯度，分析沙棘克隆生长参数、ABA含量、ABA/IAA、ABA/ZR、ABA/GA₃比值的响应规律及其因果关系。结果表明：随着灌水强度的增大，克隆生长(分株生长、克隆繁殖、克隆扩散)能力先升后降，而ABA含量及其比值先降后升，两者呈极显著负相关关系。因此，随着灌水强度“过小—适宜—过大”的变化，中国沙棘通过ABA制约的克隆生长调节形成与之相适应的克隆生长格局连续体“游击型—聚集型—游击型”。其中，“聚集型”格局以分株大、数量多、扩散能力强为特征，有利于种群稳定性和克隆持久性维持；“游击型”格局以分株小、数量少、扩散能力弱为特征，有利于种群对水分胁迫的适应，但以降低分株生长、克隆繁殖和克隆扩散能力为代价，提高了种群的早衰概率。

The Abscisic Acid Regulation Mechanism for Clonal Growth of Hippophae rhamnoides ssp. sinensis

Most researches focus on external mechanisms for the clonal growth regulation of Hippophae rhamnoides ssp. sinensis. In order to explore the Abscisic acid regulation mechanism for its clonal growth regulation. The soil water gradients were prepared by controlling the irrigation intensity. The responses of the clonal growth parameters, ABA content, and the ratios of ABA/IAA, ABA/ZR, and ABA/GA3 to the water gradients were analyzed, and the causal relationships between them were further examined. The findings indicated that the clonal growth (ramets, clonal propagation, clonal proliferation), increased first and then decreased with increasing irrigation intensity, while the ABA content and its ratios to other plant growth regulators showed a reverse trend. Therefore, with the change of irrigation intensity as ′deficit-balance-surplus′, the clonal growth of the plant patterned as ′scatter-cluster-scatter′, being regulated by ABA. The ramet in ′cluster′ is thickset with large quantity and strong in diffusion ability, which is beneficial to population stability and clonal persistence. The situation of the ′scatter′ is just the opposite of the ′cluster′, being favor to population adaptation to water stress at the expense of reducing the ramets growth, clonal propagation and the diffusion ability, which increased the probability of premature aging.