新温185号核桃根系呼吸特性及其对土壤氮素反应机理研究

根系是树木吸收养分、水分的重要器官，根系和地上部分生物量的分配形式决定着地上生物量的收获量，养分（尤其是氮）供给是改变生物量分配格局的重要因素，也是影响森林生产力的主要因素之一。根系呼吸为树木吸收、运输、同化养分提供能量的过程，但同时也是大量消耗光合产物的过程。所以，通过水肥控制调整根系呼吸是实现地上生物量收获最大化的根本。项目以新疆南疆盆地早实核桃主栽品种新温185号为研究对象，采用典型调查和控制环境、部分控制环境模拟试验相结合的方法，从不同径级根系呼吸动态（包括生长呼吸和维持呼吸）、根系呼吸对土壤氮供给量的反应、不同径级根系碳水化合物组成与含量、不同径级根系吸收能力（如活性吸收面积、质膜ATP酶活性）等研究入手，探讨根系级别与功能间的相关性，旨在阐明氮素供给对根系呼吸的调控机理，为新温185号核桃的养分管理提供理论依据。

Root is an important organ which absorbs nutrient and water. The biomass accumulation of aboveground is affected by the biomass partitioning pattern between root and aboveground part of plant. Nutrient, especially nitrogen, is one of key factors to altering biomass allocation pattern, and is also one of important factors to influence forest productivity. Root respiration is a process of providing energy which is used to absorb, transport and assimilate nutrients, as well as a process of photosynthetic consumption. Thus root respiration modulated by means of water and nutrient contol is the foundation to maximize aboveground biomass accumulation. In the study, Xinjiang precious walnut Juglans regia‘Xinwen185’ will be taken as the research object. Combining typical investigation with simulating study in control or semi-control environment will be adopted in the study. And respiration dynamic of root in different diameter and in different ranks, including growth respiration and maintenance respiration, the responses of root respiration to soil nitrogen availability, the content and components of root carbohydrates, and the absorption ability of root in different diameter in terms of active absorption area and the plasma membrane H+-ATPase will be studied in this research programme. The aims of the study are to explore the relationship between the division of root diameter class and its function plantation, and to illuminate the response regularity of root respiration to soil nitrogen supply and providing the theory basis for nutrient management of J. regia ‘Xinwen185’.