胡杨叶片解剖特征及其可塑性对土壤条件响应

表型可塑性对极端干旱区植物个体适应具有重要的意义。该研究选择内蒙古额济纳胡杨林内不同土壤条件下胡杨个体，对其叶片解剖结构与土壤因子关系进行分析，阐明不同土壤条件下叶片解剖结构及其可塑性规律。结果表明：除主脉木质部与维管束面积比外，异质性的土壤条件下胡杨叶片各解剖结构均存在明显的趋异适应；土壤水、盐条件影响了以上表皮细胞为代表的表皮组织的生长发育，土壤肥力影响了以主脉维管束为代表的输导组织以及栅栏组织的生长；生境环境异质性是胡杨叶片解剖结构可塑性的根本原因，解剖结构可塑性使得胡杨在不同环境、同一环境不同结构形成适应性差异，不同土壤条件下叶片主脉木质部、主脉维管束的可塑性较大，是胡杨适应异质性土壤条件的主要结构。叶片解剖结构特征及其可塑性对胡杨适应干旱环境具有重要生态作用。

Plasticity Response of Leaf Anatomical Characteristics of Populus euphratica in Different Soil Conditions

Phenotypic plasticity play the important role in the plant individual adaptation in extreme arid region. In this study, leaf anatomical structures of Populus euphratica were quantitatively analyzed to reveal the differences of phenotypic adaptive plasticity in three different soil conditions(Erdaoqiao, Qidaoqiao, Badaoqiao) in Egina, Innermongolia. The results showed that leaf anatomical structures of P. euphratica presented obvious divergence phenomenon in the heterogeneous soil conditions. Leaf anatomical structures of P. euphratica in Erdaoqiao, Qidaoqiao, Badaoqiao had different degrees of differences except main vein xylem/main vascular bundle area, and spongy tissue thickness had significant differences among three soil conditions. Soil moisture and salinity affected growth of epidermal tissue in represents of upper epidermal cell, and soil fertility affected growth of conducting tissue in represents of the main vein vascular bundle and palisade tissue in Ejina. Environmental heterogeneity is the root cause of leaf anatomical plasticity of P. euphratica. Leaf anatomical plasticity make P. euphratica adapt to different environments and different structures form adaptability difference in the same environment. Variation coefficient and plasticity index of the main vein xylem area and the main vein vascular bundle area were high, which showed main vein xylem and main vein vascular bundle were the major structure of P. euphratica in response to conditional changes. Leaf anatomical structure characteristics and its plasticity are the important adaptive strategy of P. euphratica in the dryland.