【摘要】 以2种一年生盐生草本植物钠猪毛菜、盐生草为试验对象,研究干旱和盐分胁迫对2种盐生植物生长和生物量分配的影响。结果表明:不同程度干旱和盐分胁迫显著影响了2种盐生植物的生长、生物量积累和生物量的分割。生长分析表明:2种盐生植物在生长率、根冠比、叶面积比方面皆存在明显可塑性,且根冠比、叶面积比的变化均受到个体发育漂变的影响;在整个营养生长期的不同处理组中,根冠比、叶面积比总体上呈逐渐降低趋势。不同干旱胁迫处理下2种盐生植物的根冠比和叶面积比的变化与最优理论和模型的预测相一致;随干旱胁迫的加重,根冠比增大而叶面积比减小。但在盐分胁迫条件下,2种盐生植物并未出现基于最优分配理论来调节生物量分配模式,且2种盐生植物根冠比和叶面积比的响应表现出明显的种间差异。此外,不同处理组间植物生物量分配特征(根冠比、叶面积比)的差异,往往只存在于生活史的某一时期,在整个营养生长期间,并不自始至终保持一致。更多还原

【Abstract】 Some plants of the annual desert halophyte species,Salsola nitraria and Halogeton glomeratus,were potted under controlled conditions of two separate gradients of drought and salt stress,and their seeds were gathered from their natural habitats.Frequent harvests were used to determine the response of growth and allocation(root vs.shoot,and leaf area vs.biomass) of the 2 species during a 70-day period so as to understand the effects of soil drought and salt stress on the growth and biomass allocation of these plants,find out whether these plants respond to the environment change by adjusting biomass allocation among various vegetative organs,and determine whether some suitable measures can be taken for the biomass allocation with optimal partitioning theory.The results reveal that the different gradients of drought and salt stress affect significantly the growth,biomass accumulation and biomass partition of the 2 desert halophyte species.The analyzed results also reveal that there is an obvious plasticity in the growth,root-canopy ratio and leaf area ratio of these halophyte species,and the root-canopy ratio and leaf area ratio are affected by the ontogenetic drift,that is the root-canopy ratio and leaf area ratio are in a gradual decrease trend during the vegetative period.Under the different gradients of drought stress,the change values of root-canopy ratio and leaf area ratio of these halophyte species accord with the results predicted with the optimal theory and model,that is the root-canopy ratio is increased but the leaf area ratio is decreased with increasing the drought stress.However,the change of biomass allocation of these annual desert halophyte species does not occur with changing the salt stress,and the responses of root-canopy ratio and leaf area ratio of these 2 species to varying gradients of salt stress are different.更多还原