Laboratory of Plant Molecular Physiology, Centre of Biotechnology Borj-Cédria, P.B. 901, Hammam-Lif 2050, Tunisia.
Micron. 2014 Jan;56:68-72. doi: 10.1016/j.micron.2013.10.010. Epub 2013 Oct 21.
Cladode ultrastructural features of two prickly and two spineless Opuntia ficus-indica cultivars were examined using environmental scanning electron and atomic force microscopies. Observations focused on cladode as well as spine and glochid surface micromorphologies. Prickly cultivars were characterized by abundant cracked epicuticular wax deposits covering the cladode surface, with an amorphous structure as observed by AFM, while less abundant waxy plates were observed by ESEM on spineless cultivar cladodes. Further AFM observations allowed a rough granular and crystalloid epicuticular wax structure to be distinguished in spineless cultivars. Regarding spine micromorphology, prickly cultivars had strong persistent spines, observed by ESEM as a compact arrangement of oblong epidermal cells with a rough granular structure. However, deciduous spines in spineless cultivars had a broken transversely fissured epidermis covering a parallel arrangement of fibres. Through AFM, the deciduous spine surface presented an irregular hilly and smooth microrelief while persistent spines exhibited rough helical filamentous prints. ESEM and AFM studies of cladode surfaces from prickly and spineless cactus pear cultivars revealed valuable micro-morphological details that ought to be extended to a large number of O. ficus-indica cultivars.
采用环境扫描电子显微镜和原子力显微镜观察了两种带刺和两种无刺仙人掌果品种的茎刺超微结构特征。观察重点是茎刺、刺和钩毛的表面微观形态。带刺品种的茎刺表面覆盖着大量的裂片状表皮蜡质沉积物，用原子力显微镜观察呈无定形结构，而无刺品种的茎刺表面则观察到较少的蜡质板。进一步的原子力显微镜观察可以区分无刺品种茎刺表面粗糙的颗粒状和结晶状表皮蜡质结构。关于刺的微观形态，带刺品种的刺用扫描电子显微镜观察呈紧密排列的长形表皮细胞，具有粗糙的颗粒状结构。然而，无刺品种的脱落刺的表皮呈横向破裂，覆盖着纤维的平行排列。通过原子力显微镜观察，脱落刺的表面呈现出不规则的丘陵和平滑的微观起伏，而持久性刺则表现出粗糙的螺旋丝状痕迹。对带刺和无刺仙人掌果品种茎刺表面的扫描电子显微镜和原子力显微镜研究揭示了有价值的微观形态细节，这些细节应该扩展到大量的 O. ficus-indica 品种。
