山药不同种质资源的叶下表皮微形态研究

Micro-morphology of leaf abaxial epidermis in different germplasms of Dioscorea polystachya

为了解山药种质资源间的相互关系、消除品种混乱,为选育优良品种提供理论依据,对33份山药种质资源的叶下表皮微形态进行显微观察。结果表明,山药叶下表皮细胞形状均为不规则形,表皮细胞大小变化显著,垂周壁类型有平直、微波状弯曲、波状弯曲及深波状弯曲。气孔器类型均为不定型,形状有椭圆形及长椭圆形;气孔器大小和气孔指数变化较稳定,而气孔器密度在种质资源间差异较大。提出的"细胞形状系数"是指某一细胞平周壁的表面积与周长同该细胞垂周壁相等的圆的面积之百分比,可定量地反映细胞形状变异程度,其值为19.31%～70.60%。根据山药叶下表皮微形态特征可将33份山药种质资源分成4个类型。

In order to reveal the relationships of germplasms of Dioscorea polystachya, eliminate the confusion of its cultivars and provide theoretical base for breeding,the micro morphology of leaf abaxial epidermis of 33 germplasms of D. polyslachya under optical microscope were studied. The results showed that the shapes of the leaf abaxial epidermis cells were all irregular and their varieties of sizes were remarkable. The anticlinal walls are straight, sinuolate, sinuous or sinuate. All of the stomatal apparatuses are anomocytic types and their shapes are elliptic and long-elliptic. Among the 33 different germplasms, the variation of stomatal size and index was small but the stomatal density was large. The‘Cell Form Coefficient＇, which was the area percent of a cell＇s perielinal wall to a circle which the perimeter is the same with the cell＇s anticlinal wall＇s, was tentatively suggested. From 19.31 %to 70.60%, the value of Cell Form Coefficient can reflect the irregular level of epidermis cells quantificationally and four types were recognized according to the leaf abaxial epidermis micro-morphological characters of the 33 germplasms.