Regional Distribution Characteristics Of Stem And Leaf Morphological Structure Of Three Sandy Plants

To study the response of the morphology and structure of the sandy plants to the regional differentiation,in this research,taking Hedysarum laeve,Caragana Microphylla and Nitraria sibirica which from Hulunbuir,Horqin,Hunshandake and MuUs sandy land as research objects,field measurement,paraffin section technology and leaf dissociation technology were used to observe and analyze the regional differentiation characteristics.Morphology and tissue structure of each plant stems and leaves were studied,and also,the correlation between plant morphology,structure and ecological factors were analyzed by Correlation Analysis software.The results showed that:(1)There were different differences in morphology and anatomical structure of three kinds of plant stems and leaves from different regions,among which the stem and leaf morphology and structure of Hedysarum laeve and Caragana microphylla from Hunshandake and Horqin Sandy land were the most significant and Nitraria sibirica stems from Hulunbeier sandy land and Horqin Sandy Land;the difference of leaf morphological structure was the most significant.(2)With the increase of drought degree,the epidermis thickness,cortical thickness and diameter of three kinds of plant stems increased,the diameter of medullary cavity decreased,the upper and lower epidermal cells of leaves thickened,the more developed the fencing tissue,the degeneration and even disappeared of sponge tissue,the diameter of the main vein vascular bundle became larger and the stomatal density decreased.(3)Due to the long-term effects of arid environment,there are a large number of idioblast in the anatomical structure of the stems and leaves of Hedysarum laeve,which have the functions of resisting drought and storage,and the number of heterogeneous cells per unit area near the upper and lower epidermis increases with the increase of drought degree.(4)The correlation between meteorological factors and the measured indexes of stems and leaves of three sandy plants in different regions was analyzed.It was concluded that annual average precipitation,seasonal precipitation and annual average evaporation were the main factors affecting the morphological and structural changes.The epidermal thickness,diameter and pith diameter of stems,leaf thickness,thickness of upper and lower epidermal cells,thickness of palisade tissue,stomatal density and meteorological factors were the main factors.The correlation is large.