School of Geology and Environment, Xi’an University of Science and Technology
Research Institute of Mining and Ecological Environment Restoration in West China, Xi’an University of Science and Technology
State Key Laboratory for Coal Resources and Safe Mining, China University of Mining and Technology-Beijing

干旱半干旱区煤矿露天开采破坏了地表形态，加速水土流失，水资源的缺失严重影响了露天矿排土场植被恢复的效果。土层重构与微生物修复技术为解决露天矿排土场植被缺水困境指明了方向，但目前对土层重构下植物根系形态特征与土壤水分利用的关系以及深色有隔内生真菌(DSE)在其中起到的重要作用缺乏足够的认识，因此，本研究旨在探究土层重构模式下玉米根系生长和水分利用情况以及DSE的作用机制。研究对象为玉米，在温室进行为期4个月的土层重构室内模拟试验。试验布设3组处理，分别为空白对照(N-CK)、土层重构不接种DSE(L-CK)、土层重构且接种DSE(L-DSE)。试验结果表明：① 与纯砂土处理相比，土层重构处理的玉米根系总根长度降低了39.7%，根系中小于0.3 mm细根的比例提高了8.86%，深层(50～70 cm)土壤水分的利用率提高了16.1%。② 与土层重构不接种DSE处理相比，接种DSE玉米的叶片脯氨酸含量提高了69.8%，30～50 cm土层根系根尖数、比根长分别提高了106.6%、38.5%，且深层水分的利用效率相较于纯砂土处理及土层重构不接种DSE处理分别增加了29.3%、11.1%。③ 玉米根系的根尖数与比根长是土层重构模式下实现对深层土壤水分高效利用的关键根系特征。综合研究表明，土层重构有助于优化玉米根系结构，提高细根所占比例及根尖数目，改善缺水环境下玉米的水分利用模式，且土层重构模式下接种DSE可以通过提高玉米叶片脯氨酸含量，优化玉米根系结构等途径提高对深层土壤水分的利用率，进而提高作物的长期抗旱能力。

Open-pit mining of coal mines in arid and semi-arid areas destroys surface morphology, accelerates soil water loss, and the lack of water resources seriously affects the effect of vegetation restoration in open pit dump. Soil reconstruction technology and microbial remediation technology point out the direction to solve the water shortage dilemma of vegetation in open pit dump, but the relationship between plant root morphological characteristics and soil water use efficiency under soil reconfiguration and the important role of dark septum endophytic fungi (DSE) in soil reconfiguration are not well understood. The purpose of this study was to explore the root growth and water use of maize under soil layer reconstruction mode, as well as the mechanism of DSE. The study object was maize, and the soil layer reconstruction experiment was simulated in a greenhouse for 4 months. The experiment was arranged in three groups: blank control(N-CK), soil layer reconstruction without DSE inoculation(L-CK), soil layer reconstruction with DSE inoculation(L-DSE). The results showed that: ① Compared with blank control treatment, the total root length of maize root system under soil layer reconstruction treatment was reduced by 39.7%, the proportion of fine roots less than 0.3mm in the root system was increased by 8.86%, and the water use efficiency of deep (50−70 cm) soil was increased by 16.1%. ② Compared with the reconstructed soil layer without DSE inoculation, the proline content in leaves of maize inoculated with DSE increased by 69.8%, the number of root tips and specific root length in 30−50 cm soil layer increased by 106.6% and 38.5%, respectively. In addition, the water use efficiency in deep soil increased by 29.3% and 11.1%, respectively, compared with that of N-CK and L-CK. ③ Root tip number and fine root volume of the maize root system are the key root characteristics to achieve efficient use of soil water under the soil layer reconstruction model. The combined study showed that soil layer reconstruction was helpful to optimize the root structure of maize, increase the proportion of fine roots and the number of root tips, and improve the water use pattern of maize under water shortage environment, and DSE inoculation under the soil layer reconfiguration model could improve the use rate of deep soil water by increasing the content of proline in leaves and optimizing the structure of maize root system, so as to improve the long-term drought resistance of crops.

国家自然科学基金面上资助项目(51974326)；国家重点研发计划资助项目(2022YFF1303300)

毕银丽，李明超，柯增鸣，等. 土层重构模式下接种DSE对玉米根系形态及水分利用的影响[J]. 煤炭学报，2023，48(8)：3191−3203.

BI Yinli，LI Mingchao，KE Zengming，et al. Effects of dse inoculation on maize growth and water use under soil reconfiguration mode[J]. Journal of China Coal Society，2023，48(8)：3191−3203.