稻属三种植物叶片下表皮的形态比较

The Morphological Comparison of Abaxial Epidermis of Leaf in Three Oryza Species

摘要:

稻属有20多种，其中有3种和其他物种明显不同。Oryza eichingeri被认为在亚洲和非洲间断分布；O. officinalis和O. punctata被证明同时含有二倍体和四倍体。为了识别种内微形态差异, 利用光镜和扫描电镜，对这3物种的成熟叶片下表皮进行了观察。结果表明，O. eichingeri的叶脉长细胞乳突形状在种内是不一致的，除了斯里兰卡地理宗具有的瘤状乳突外，乌干达地理宗还具有长条状的乳突；同样，种内多样性也存在于O. officinalis和O. punctata内，特别存在于它们不同倍性的细胞型间。在O. officinalis中，四倍体有粒状气孔器外围乳突和脉带表皮毛较少，二倍体细胞型具有三角形拱状排列的气孔器外围乳突和较密集的脉带表皮毛；而在O. punctata中，和四倍体相比，二倍体具有小的长细胞表面乳突和低密度分布的气孔。这些稳定的差异为3种植物的种内鉴定和分类修订提供了新的证据。

Abstract:

The genus Oryza is agriculturally important. It includes more than 20 species, 3 of which differ particularly from the others. O. eichingeri is thought to distribute in both Asia and Africa disjunct, while the species O. officinalis and O. punctata have been confirmed to have both diploidy and tetraploidy. Abaxial epidermal characters of mature leaves in the 3 species were investigated under both light microscope (LM) and scanning electron microscope (SEM) to identify intraspecies micromorphological difference. Inconstant shape of the papillaes on the intercostal long cells within O. eichingeri was found. thane经受和 the nodular papillaes distributing on the leaf epidermis of Sri Lanka geographical race of the species, the elongate papillaes were also observed in Uganda race. Similarly, interspecies diversity existed in O. officinalis and O. punctata, especially among their different ploidies. In contrast to the granular shape papillaes around the stomata and less density of trichoma on costal zones in tetraploidies of O. officinalis, the triangle and overarching shape papillaes, and denser trachoma were observed in diploidies. Meanwhile, comparing with their tetraploid counterparts, the smallpapillaes on the intercostal long cells and low density of stoma were otherwise found in diploidies of O. punctata. These stable differences on abaxial epidermis of leaves could provide new evidences for recognition of the three species and identification of intraspecies taxa.