旱生植物刺山柑不同种群茎叶的解剖学研究

Anatomy of stem and leaf in different populations of Capparis spinosa in China

刺山柑常分布于极端干旱的戈壁与砾石山坡,然而其适应干旱环境的解剖学机理却未见报道。对分布于新疆石河子、新疆库尔勒以及西藏札达的3个刺山柑种群茎、叶材料进行了比较解剖学研究。结果表明:不同种群材料均具有适应旱生环境的典型结构特征:茎表皮有表皮毛和发达的角质层,皮层较厚,维管组织发达,髓明显;叶为双栅型等面叶,上、下表皮均有气孔分布,气孔密集,但以下表皮气孔数目为多,角质层、栅栏组织、输导组织十分发达。随着生境干旱程度的加剧,其茎、叶的旱生结构特征也愈加显著。由于库尔勒的刺山柑种群分布于干旱石质山坡的阳坡,年降水量只有50mm,而夏季岩石表面温度却高达80℃。因此,该种群植株的茎、叶比其它种群具有更为显著的旱生结构。

Capparis spinosa often lives on extremely arid Gobi desert or arid stony mountain, but there were few works about the relationship between its anatomical structure and its adaptation to arid living condition. In this pa- per, anatomical structures of stem and leaf of the cappers in different populations（Shihezi,Korla in Xinjiang, and Zhada in Tibet）were studied. The results showed that the anatomical structure was highly adapted to its arid environment： there were epidermal hairs and obvious cuticle on the epidermis of stems, and also developed cortex, pith and vascular tissue in stems. The leaf was isobilateral with double palisade tissue. Dense stomata existed on both upper and lower epidermis, there were significant cuticle,palisade tissue and conducting tissue in leaf. Its characteristics of xerophil were more obvious as available water condition in soil became worse in natural habitats. C. spinosa in Korla population was of much significant xeromorphic traits than that in other populations because of its severe arid habitat.