中文摘要：

利用体视显微镜和扫描电子显微镜观察了荒漠植物多裂骆驼蓬粘液质种皮吸水前后的形态变化,通过种子吸水-脱水、粘土、漂浮和萌发实验研究了种皮纹饰和粘液特征在种子扩散和萌发中的适应意义,以期为研究该物种在荒漠环境中的适应策略提供理论依据。结果表明：（1）多裂骆驼蓬种皮纹饰由表皮细胞外切向壁的附属物向外突起形成,呈多面体网纹状;种皮纹饰上覆盖1层粘液薄膜,将多面体网眼围成封闭的腔,种子吸水后粘液薄膜变成凝胶状,腔内有气泡产生;粘液薄膜经过反复吸水-脱水后逐渐溶解消失。（2）种皮网眼状腔室结构和粘液薄膜可使种皮纹饰内储存空气,以增强种子的漂浮能力,有助于种子扩散;种皮纹饰和粘液还增强了种子的粘土能力,使种子锚定在土壤表面,避免种子裸露和活力丧失;此外,种皮纹饰及粘液的快速吸水和保水能力能防止种子失水,有效维持该物种在荒漠环境中的土壤种子库。（3）种皮纹饰和粘液虽可抑制种子萌发,但能促进幼根的伸长生长,对增强幼苗的建植能力有一定积极作用。

英文摘要：

The characteristic changes of mucilaginous seed coat before and after wetting were observed by dissecting microscope and scanning electron microscopy.The effects of seed coat ornamentation and mucilage on water uptake,sand adhesion,floatability and germination of seeds were analyzed.The result showed that：（1）The seed coat ornamentation of Peganum multisectum was formed by outward protruding appendages on the outer periclinal walls of epidermal cells and presented a reticular structure.Pellicles covered on the polyhedral meshes of seed coat ornamentation,making the meshes form closed chambers.After absorbing water,the pellicles became mucilaginous and a lot of bubbles appeared in the muci-lage chambers.The mucilage was gradually dissolved and disappeared after water absorption-dehydration.（2）The mucilage layer and chambers of seed can store much air,which facilitated seed floatation on moving water and further dispersal.Meanwhile,seed coat ornamentation and mucilage can enhance adhesive ability of seed to the soil and other plants,thereby escaping from seeds bareness to maintain seed vigor.The seed coat ornamentation and mucilage also can absorb a large amount of water quickly and hold water,thus maintaining soil seed bank in the harsh desert.（3）The mucilaginous seed coat can delay germination but promote seedlings growth in an unpredictable environment,which increasing the ability of plant establishment.