芋营养器官中的草酸钙晶体及其可能的生理作用

利用徒手切片,在光学显微镜下对芋(Colocasia esculenta(L.)Schott)营养器官中晶体的类型和分布进行了观察和研究,并用化学方法对晶体的化学成分进行了鉴定。结果表明,芋营养器官中的晶体为草酸钙结晶体,形态上可以分为针晶和簇晶两大类。含针晶束的异细胞有3种类型:含发射型草酸钙针晶束异细胞(存在于叶片、叶柄、块茎中),含大型草酸钙针晶束异细胞(存在于叶片、叶柄、块茎、块茎皮中),含大量草酸钙针晶的管状异细胞(仅存在于不定根中)。草酸钙针晶也有散乱分布于块茎和不定根中的。草酸钙簇晶在叶片、叶柄、块茎、块茎皮、不定根中均有分布,且叶片、叶柄、块茎皮中的簇晶比块茎和不定根中的尖锐。芋营养器官中的草酸钙晶体很可能是作为一种防御机制,防止动物的取食。

Calcium Oxalate Crystals in the Vegetative Organs of Colocasia esculenta (L.) Schott ( Araceae ) and Their Possible Physiological Function

The morphology and distribution of calcium oxalate crystals in the vegetative organs of Colocasia esculenta (Araceae) were investigated by hand section under light microscope,and their chemical comstituents were identified by chemical methods. The results showed that the crystals were calcium oxalate crystals which could be divided into two types: needle and cluster crystals. There were three types of rhaphide idioblasts, such as biforines (exist in leaf, petiole and tuber), giant rhaphide bundles (exist in leaf, petiole, tuber and tuber bark), and tubular idioblast with abundant of rhaphides (only exist in adventitious root). The calcium oxalate rhaphides also scatter in tuber and adventitious root. Calcium oxalate druses crystals distribute in leaf, petiole, tuber, tuber bark and adventitious root, and the druses crystals in leaf, petiole and tuber bark were sharper than those in tuber and adventitious root. These calcium oxalate crystals in the vegetative organs of C. esculenta could be used as a defensive mechanism to prevent animal feeding.