A Systematic Study On The Genus Of Ceratoides And Its Genus

In this paper, the taxonomic status and system location of Chenopodium and the related genera was discussed by the pollen morphology of Chenopodium L., Dysphania R. Brown, Axyris L., Atriplex L.and Spinacia L. under LM and SEM. While we observe the leaf epidermal micromorphology of Chenopodium L. and the related genera to further study the relationship of various species within Chenopodium L. and the related genera.1、Pollen morphologyA pollen morphology study of 18 species of Chenopodium L. and the related genera in china was taken in this paper. Acetic anhydride decomposition method was adopted. We observed them under under light microscope and transmission electron microscope. It was found that pollen grains are radially symmetrica and spheroidal. There are some differences in average value of size. The pollen grains are porous and pantopolyporate. The aperture is rotundate. Their exine structure is similar. The exine has two layers. Ektexine overlying endexine is thick. Endexine has horizontal stripes which is vertical to contours. Under the electron microscope, we can see that the exine ornamentation is granulate. Grana size, density and clarity are different in different species. The pollen of chenopodium has a diversity on some morphological features, but only manifested in some quantifiable characteristics, such as the size of the pollen, aperture number and size, the number of small spines, but these features is not stable enough in Chenopodium and having a certain variation range. It is not convenience for the study of Chenopodium, and has not found significant regularity in the Chenopodium.2、Leaf epidermal micromorphologyIn this paper we choose 14 species leaf blade of Chenopodium L. and related genera in china, observe leaf blade under light microscope and give a statistics and analysis to epidermal cell shape, anticlinal wall style, stomatal apparatus type, stomatal aspect ratio and so on. The result reveal that 1) The epidermal cell shape of Chenopodium and related genera is polygonal or irregular shape; The anticlinal wall is straight to curved or wavy bow; The upper epidermis have stomatal apparatus or not; The lower epidermis have stomatal apparatus; The type of stomata is anomocytic type; 2) In the study of leaf epidermal micromorphology,there is not obvious regularity in stomatal aspect ratio, stomatal density and stomatal index; 3) The upper and lower epidermal cell of Dysphania aristata and Dysphania schraderiana are all irregular shape, The anticlinal walls are all waveshap, They have a close relationship, This are consistent with the recent phylogeny result and support that put them in the same tribe Dysphanieae. And because of that the anticlinal wall of Dysphania aristata is shallow wave,that of Dysphania schraderiana is wave,so the two should be setted in different genera: The former belongs to genera Teloxys,the latter belongs to genera Dysphania; 4) The upper epidermal of Chenopodium hybridum and Axyris hybridum don’t have stomatal apparatus and the lower epidermal of them have stomatal apparatus. But they belongs to different genera. Their relation need further study; 5) The recent phylogeny support that C. glaucum and C. urbicum subsp. sinicum should be setted in the same genera Oxybasis,But their leaf epidermal micromorphology don’t support it, Sukhorukov take a carpological study about chenopodiaceae and he also don’t support it.