ObjectiveTo investigate the alleviating effect of calcium cyanamide （CaCN₂） soil fumigation on replanting problems of Rehmannia glutinosa. MethodsNewly soil （NP） was used as the control group， while three treatment groups were established： replanted soil （RP）， newly soil treated with CaCN₂ （120 g·m²， tillage depth 25 cm） （NPCC）， and replanted soil treated with CaCN₂ （RPCC）. R. glutinosa was cultivated in all groups. At harvest， the tuber agronomic traits （number of enlarged roots， maximum root diameter， fresh weight， dry weight） were measured. The content of catalpol and rehmannioside D was quantified by ultra-high-performance liquid chromatography （UPLC） to evaluate medicinal quality. Rhizosphere soil available nutrients and enzyme activities were analyzed by assay kits. The community structure and composition of fungi and bacteria in rhizosphere soil were assessed via internal transcribed spacer 2 （ITS2） sequencing and 16S rDNA sequencing， respectively. ResultsCompared with NP， the RP group showed obviously reduced in tuber agronomic traits and quality indicators （P0.05）. However， the RPCC group showed significant improvement in agronomic traits and a notable increase in rehmannioside D content compared to RP （P0.05）. The contents of available phosphorus and potassium in RPCC and NP groups were obviously lower than those in RP （P0.05）. The polyphenol oxidase soil （S-PPO） activity in RP was obviously lower than in NP （P0.05）， while sucrose soil （S-SC）， acid phosphatase soil （S-ACP）， and S-PPO activities in RPCC were obviously higher than in RP （P0.05）. Microbial richness and diversity in RP were obviously higher than in NP （P0.05）， whereas no significant differences were observed between the RPCC and NP. The relative abundances of fungal genera Nectria， Myrothecium， Tomentella， and bacterial genus Skermanella were obviousl lower in RPCC and NP than in RP （P0.05）. Correlation analysis that S-ACP activity was positively correlated with the content of rehmannioside D （P0.05）. Fungal genera Engyodontium and Alternaria， and bacterial genera Pir4 lineage， Pirellula， Methyloversatilis， Brevundimonas， Ralstonia， and Acidibacter were obviously positively correlated with tuber dry weight （P0.05）. Conversely， fungal genera Pseudaleuria， Nectria， Haematonectria， Ceratobasidium， and bacterial genera Streptomyces， Skermanella， RB41， Gemmatimonas， and Bacillus were obviously negatively correlated with dry weight （P0.05）. The fungal genus Alternaria and bacterial genera Brevundimonas， Ralstonia， Acidibacter， and Dongia showed positive correlations with medicinal quality of R.glutinosa tuber， while fungal genera Pseudaleuria， Nectria， Stachybotrys， Fusarium， Gibberella， Ceratobasidium， and bacterial genera Sphingomonas， Skermanella， RB41， Gemmatimonas， and Bacillus were obviously negatively correlated （P0.05）. ConclusionCaCN₂ soil fumigation can significantly improve enzyme activities in replanted Rehmannia rhizosphere soil， enhance the utilization of available nutrients， reshape microbial community structure of replanted R.glutinosa at the family and genus level， and notably improve tuber agronomic traits and medicinal quality. This study provides a novel approach to alleviating replanting problems and offers insights for the integrated development of standardized cultivation techniques， including soil disinfection， nutrient-targeted regulation， and microbial inoculant application.

ObjectiveTo reveal the correlation of Rehmannia glutinosa-soil feedback process with the formation of its continuous cropping obstacles through the identification of the root exudates of R. glutinosa and analysis of the specific rhizomicrobes recruited by the root exudate. MethodThe root exudates of R. glutinosa seedlings germinated under sterilized condition and those enriched in the rhizosphere of R. glutinosa cultivated in the field were collected and analyzed using the ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry（UPLC-Q-TOF-MS）. The highly abundant compounds identified in the root exudates were added into blank soil， and the soil microbial community was profiled using Illumina Miseq sequencing. The bacterial and fungal functions were predicted by PICRUSt and FUNGuild， respectively. ResultThe identification results showed that seven phenylethanoid glycosides were found in R. glutinosa root exudates， and acteoside possessed the highest abundance. In the soil enriched with acteoside， the bacterial genera such as Agromyces， Pseudomonas， Lysobacter， Sphingobium， Pseudoxanthomonas and Sphingomonas were enriched. For the fungi， the genera Neocosmospora， Plectosphaerella and Dactylonectria， and the species such as Neocosmospora rubicola， Plectosphaerella cucumerina， Dactylonectria alcacerensis and Fusarium solani showed higher abundance. The functional analysis indicated the above-mentioned bacterial genera may realize rapid proliferation by utilizing， biodegrading and transforming phenylethanoid glycosides， and some potential fungal pathogens were colonized. ConclusionThe R. glutinsoa-soil feedbacks were likely generated by the phenylethanoid glycosides in the root exudates together with the specific rhizomicrobes. The investigations of R. glutinsoa-soil feedbacks under continuous cropping system are critical to the further understanding of the underlying mechanisms related to its continuous cropping obstacles.

Aptamers are oligonucleotides which can combine targets with high affinity and specificity.Graphene oxide is a kind of new material with many unique physical and chemical properties.Recently, graphene oxide is gradually applied to the field of aptamers and has made a series of progress.This review focused on the application progress of graphene oxide and aptamers in the detection of different targets including small molecules and metal ion, biomacromolecules and cells in order to provide references for the mass application of graphene oxide and aptamers in the field of detection .