Study On The Morphological Anatomy Of Elymus L. Plants

In this study, 18 wild germplasm materials of 5 species of Elymus L. were collected from seven provinces such as Inner Mongolia, Ningxia, Gansu, Xinjiang, Qinghai and Tibet. Comparative studied were carried deeply and carefully from morphological characteristics, leaf epidermal features, transverse section structures of leaves and stems, the main results as follows:1. Phenotypic variation was assessed by measuring 19 characters to Elymus subiricus L., Elymus excelsus T., Elymus dahuricus T., Elymus cylindricus(Franch.)Honda and Elymus nutans. The results showed that the different characters had different variation, some characters including flag leaf length, flag leaf width, number of spikelet, the first internode length, lemma awn length, glume length, glume awn length had higher coefficient of variance than others. These seven features are the main variance characters.2. The anatomaical structures of leaves were the same among these species, comprised of leaf epidermal cells, leaf tissues and leaf veins. While vascular bundle diameter, upper epidermis thickness, cuticular thickness, midrib enation and the morphology of leaf margin had significant variation among species (P<0.05).3. The characteristics of lower epidermis cells of five species were familiar with regular shape and dense arrangement. While the size of lower epidermis cell and stomata apparatus, the morphology of subsidiary cell and anticlinal wall had significant variation among species(P<0.05). The morphological variation and quantitative parameters can be considered as the principle of the species classification of Elymus L., stomatal index and stomatal length as the parameters of Elymus L. resistance.4. Among the lower epidermis indices, stomata length, stomata width, the length of long cell and the shape of subsidiary cell had different correlation with five ecological factors, such as altitude, latitude, longitude, annual average temperature and annual precipitation. Stomata length, long cell length and the shape of subsidiary showed very significant positive correlation with latitudes, while stomata width showed significant negative correlation with altitude.5. Compared of stem anatomic structure of two Elymus excelsus T. from different source, the result showed that a material of Ningxia was better than anther of Xinjiang because of the Ningxia material having a strong vascular tissue. The strong vascular tissue leaded to a strong effect of transportation and support.Compared the heading stage with maturing stage of stem anatomic structure, it was showed some different characters. The stem transverse section of heading stage had some characters as followed. The outer had a leaf sheath transverse section which was wide and the immaturity tissue; the inside was the main stem transverse section which had undifferentiating vascular bundle; pith cavity did not exist in the middle stem.6. The main prominent morphological difference of leaf lower epidermic cell and the quantitative varivance indexs of the leaf transverse section can be tried as genetic mark to identifiy the intraspecific and interspecific genetic variation of Elymus L.