Sun Jinhua, Rong Zheng, Yang Liu, Zhu Qimeng, Yuan Yabo, Feng Zhipei, Li Limei, Li Nixuan, Zhang Lei, Guo Shaoxin
College of Forestry, Henan Agricultural University, Wenhua Road of Jinshui District in Zhengzhou City of Henan Province, Zhengzhou 450002, China.
Henan Ecological and Environmental Monitoring Center, No. 10 Xueli Road, Zhengdong New District, Zhengzhou City, Henan Province, Zhengzhou 450046, China.
Tree Physiol. 2024 Feb 6;44(1). doi: 10.1093/treephys/tpad130.
Root pruning hinders the absorption and utilization of nutrients and water by seedlings in the short term. Arbuscular mycorrhizal fungi (AMF) are an important source of nutrient and water for seedlings except for the root system. However, the mechanism by which AMF affect the physiological growth of seedlings after root pruning has rarely been studied. In this study, a pot experiment was conducted through a three-compartment partition system to clarify the effects of Funneliformis mosseae (F. mosseae) strain BGC XJ07A on the physiological growth of root-pruned Robinia pseudoacacia seedlings. Five root pruning treatments (zero, one-fifth, one-fourth, one-third and one-half of the taproot length were removed) were applied to noninoculated seedlings and those inoculated with F. mosseae. The results showed that the presence of F. mosseae significantly increased the shoot and root biomasses, leaf photosynthetic rate, stomatal conductance and transpiration rate. The root projected area, root surface area, average root diameter, root density, root volume and number of root tips of the inoculated seedlings were higher than those without inoculation in all root pruning treatments. The root cytokinin, gibberellins and indole-3-acetic acid concentrations, but root abscisic acid concentration, were higher than those measured in the absence of inoculation in all root pruning treatments. Moreover, the changes in the root endogenous hormone concentrations of the seedlings were closely related to the root morphological development and seedling biomass. The AMF increased the soil available nitrogen, soil available phosphorus, soil available potassium and soil organic matter concentrations compared with the noninoculated treatment. These results indicate that AMF can alleviate the adverse effects of root pruning on the physiological growth of R. pseudoacacia and soil properties, and can provide a basis for AMF application to forest cultivation and the sustainable development of forest ecosystems.
根系修剪在短期内会阻碍幼苗对养分和水分的吸收与利用。丛枝菌根真菌（AMF）是除根系外幼苗重要的养分和水分来源。然而，AMF影响根系修剪后幼苗生理生长的机制鲜有研究。本研究通过三室分隔系统进行盆栽试验，以阐明摩西管柄囊霉（F. mosseae）菌株BGC XJ07A对根系修剪的刺槐幼苗生理生长的影响。对未接种和接种F. mosseae的幼苗进行了五种根系修剪处理（去除主根长度的零、五分之一、四分之一、三分之一和二分之一）。结果表明，F. mosseae的存在显著增加了地上部和根系生物量、叶片光合速率、气孔导度和蒸腾速率。在所有根系修剪处理中，接种幼苗的根系投影面积、根表面积、平均根直径、根密度、根体积和根尖数量均高于未接种的幼苗。在所有根系修剪处理中，根系细胞分裂素、赤霉素和吲哚 - 3 - 乙酸浓度均高于未接种时的测定值，但根系脱落酸浓度除外。此外，幼苗根系内源激素浓度的变化与根系形态发育和幼苗生物量密切相关。与未接种处理相比，AMF提高了土壤有效氮、土壤有效磷、土壤有效钾和土壤有机质浓度。这些结果表明，AMF可以缓解根系修剪对刺槐生理生长和土壤性质的不利影响，并可为AMF在森林培育中的应用及森林生态系统的可持续发展提供依据。
