类芦根系对不同强度干旱胁迫的形态学响应

为了探讨类芦根系对干旱胁迫逆境的响应规律，为其在水土流失区推广和应用提供科学理论依据，以水土保持先锋植物类芦为研究对象，通过4个不同干旱强度胁迫的盆栽试验，测定不同干旱处理对类芦根系生物量和根系形态指标。结果表明：不同干旱强度胁迫处理，类芦根系总长度、表面积、平均直径、根系生物量的差异明显，而根体积差异较小。在不同程度干旱胁迫下，根体积、根平均直径随着干旱胁迫程度增加逐渐减小，且均比充足供水的小；而类芦根系总长度、根表面积、根系生物量、根冠比均比充足供水的大，中度干旱胁迫条件下（田间持水量40%±5%），类芦的根系长度、根表面积、根系生物量、地上部生物量、根冠比均为最大。类芦具有庞大的根系，抗旱和耐旱能力强；类芦根系增强延伸能力、扩大与土壤接触面积是对干旱逆境的形态学响应机制之一。

Morphological Response to Different Drought Stress in the Roots of Neyraudia reynaudiana

In order to discuss the response law of root in Neyraudia reynaudiana to drought stress, and provide scientific theoretical basis for the promotion and application of Neyraudia reynaudiana in soil erosion area, taking pioneer species Neyraudia reynaudiana which was widespread in southern China region of water and soil conservation as the research object, pot experiment with 4 different drought stress was designed, root morphology index and biomass distribution were determined in different treatments, and morphological response to drought stress was researched. The results showed that among treatments with different drought stress, there was significantly different in total root length, root surface-area, root average diameter, root biomass of Neyraudia reynaudiana, but not in the root volume. The root volume and root average diameter decreased with increasing drought stress, and there were lower under drought stress than enough water supplies. The total root length, root surface-area, root biomass, root-shoot ratio were greater under drought stress than enough water supply, and there were the largest under moderate drought stress with field moisture capacity by 40%±5% among different treatments. Neyraudia reynaudiana had strong drought-resistant and drought-tolerant, because it had a large root system with root length and root surface-area. Information on the response of root characters of elongation growth and enlargement root-soil interface of Neyraudia reynaudiana would provide one of useful information for explaining mechanisms of morphology response under drought stress.