PDF(Pubmed)
Abstract：
Arundo donax L. (Arundinoideae subfamily, Poaceae family) is a sub-tropical and temperate climate reed that grows in arid and semi-arid environmental conditions, from eastern China to the Mediterranean basin, suggesting potential adaptations at the epicuticular level. A thorough physical-chemical examination of the adaxial and abaxial surfaces of A. donax leaf was performed herein in an attempt to track such chemophenetic adaptations. This sort of approach is of the utmost importance for the current debate about the hypothetical invasiveness of this species in the Mediterranean basin versus its natural colonization along the Plio-Pleistocene period. We concluded that the leaf surfaces contain, apart from stomata, prickles, and long, thin trichomes, and silicon-rich tetralobate phytolits. Chemically, the dominating elements in the leaf ashes are oxygen and potassium; minor amounts of calcium, silicon, magnesium, phosphorous, sulphur, and chlorine were also detected. In both surfaces the epicuticular waxes (whose density is higher in the adaxial surface than in the abaxial surface) form randomly orientated platelets, with irregular shape and variable size, and aggregated rodlets with variable diameter around the stomata. In the case of green mature leaves, the dominating organic compounds of the epicuticular waxes of both surfaces are triterpenoids. Both surfaces feature identical hydrophobic behaviour, and exhibit the same total transmittance, total reflectance, and absorption of incident light. The above findings suggest easy growth of the plant, remarkable epidermic robustness of the leaf, and control of water loss. These chemophenetic characteristics and human influence support a neolithization process of this species along the Mediterranean basin.
摘要：
ArundodonaxL.（Arundinoideae亚科，禾本科科）是一种亚热带和温带气候的芦苇，生长在干旱和半干旱的环境条件下，从中国东部到地中海盆地，提示在表皮水平的潜在适应。在本文中对A.donax叶的正面和背面进行了彻底的物理化学检查，以试图追踪这种化学表型适应。这种方法对于当前有关该物种在地中海盆地的假设入侵与上新世时期的自然定殖的辩论至关重要。我们得出结论，叶子表面包含，除了气孔,刺,和长,薄的毛状体，和富含硅的四乙醇酸盐植物tolits。化学上,叶灰中的主要元素是氧和钾；少量的钙，硅，镁，磷,硫磺,还检测到氯。在两个表面中，表皮蜡（其密度在前轴表面高于在后轴表面中）形成随机取向的血小板。不规则的形状和可变的大小，和围绕气孔的直径可变的聚集小棒。在绿色成熟叶子的情况下，两个表面的表皮蜡的主要有机化合物是三萜类。两个表面都具有相同的疏水行为，并表现出相同的总透射率，总反射率,和吸收入射光。上述发现表明植物容易生长，显著的表皮健壮性的叶子，控制失水。这些化学表型特征和人类影响支持该物种在地中海盆地的新石化过程。
