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Titre : The Study on the Changes of Root Architecture and Leaf Physiological Index of Reaumuria Songarica in Ejina Desert

Auteur : 高天

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé partiel
The root system is the organ that plants use to absorb water and nutrients,and it provides the material basis for aboveground photosynthesis.Moreover,the physiological indexes of leaves reflect the adaptability of plants to the environment.Therefore,studying the morphological structure of roots,C and N content,and leaf protective enzyme characteristics is of great significance for revealing the adaptation strategies of root structures and functions to environmental physiology.The Reaumuria songarica community,which grows in the Ejna Desert Area,was selected as the study object.The temperature,humidity,and rainfall in the Reaumuria songarica habitat were observed.Besides,the soil moisture content,p H value,and electrical conductivity were also determined.Root system tracking methods were adopted to collect the complete root system of the Reaumuria songarica,and the root system architecture of Reaumuria songarica was analysed.Meanwhile,the C and N content in the root system as well as the protective enzyme activity and content of malondialdehyde in the leaves were measured.Additionally,the root system architecture and changes in leaf physiological indicators of Reaumuria songarica were investigated.Results indicated that:1.In the Ejna Desert,the soil texture of the Reaumuria songarica habitat was sandy soil.Also,the soil moisture content and volume weight increased with soil depth.The moisture content in the 40-60 cm soil layer was between 4.0%-6.7%,and the volume weight of the surface soil and 70-100 cm soil layer was 1.46-1.56 g/cm 3and 1.57-1.76g/cm 3,respectively.In the area with lower soil bulk density 1.46-1.64 g/cm 3,the number of Reaumuria songarica radical axes was 14-16,and the length of the main root was approximately 69 cm.In the area with higher soil bulk density,the number of radical axes was 16-20,and the main root length was around 65 cm.To adapt to hard dry soil,the lateral root branches,lateral root number,and total lateral root length of Reaumuria songarica increased,which indicates that the Reaumuria songarica root has morphological plasticity.2.The topological index of the Reaumuria songarica root system in the Ejna Desert was small,and its topological indexes reached 0.08±0.01.Furthermore,the root system branching patterns were similar to a forked branch structure.Reaumuria songarica roots featured good fractal characteristics,as the fractal dimension was 1.17±0.02 and the fractal abundance reached 1.44±0.03.Besides,fractal dimension and fractal abundance had a significant positive correlation with the average root connection length.Due to the larger average connection length of the Reaumuria songarica root system,its effective nutrition space was expanded

Mots clés : Reaumuria songarica ;Specific root length ;Specific surface area ;Carbon nitrogen ratio ;Root sequence ;Topology coefficient ;Protective enzyme ;

Présentation (CNKI)