OBJECTIVETo study the chemical constituents from the roots of Rehmannia glutinosa.

METHODThe compounds were isolated by various chromatographic methods and identified by spectroscopic analysis.

RESULTTwelve compounds were isolated and their structures were identified as 5-hydroxymethyl-pyrrole-2-carbaldehyde (1), 5-hydroxymethyl furfural (2), tyrosol (3), 5,6-dihydroxy-beta-ionone (4), 6-O-E-feruloyl ajugol (5), acteoside (6), leucosceptoside A (7), martynoside (8), isomartynoside (9), purpureaside C (10), jionoside A1 (11), and jionoside B1 (12).

CONCLUSIONCompounds 1, 3 and 9 were isolated from the genus Rehmannia for the first time.

Leaf blight outbroke in Rehmannia glutinosa plantation in Wenxian county, Henan province in 2019. R. glutinosa plants with diseased leaves were collected from the plantation, and three strains were isolated from the diseased leaf samples. Pathogenicity test, morphological observation, and phylogenetic analysis of ITS, EF1-α, and Tub suggested that they were respectively Fusarium proliferatum, F. oxysporum, and F.acuminatum. Among them, F. acuminatum, as a pathogen of R. glutinosa leaf disease, had never been reported. To clarify the biological characteristics of F. acuminatum, this study tested the influence of light, pH, temperature, medium, carbon source, and nitrogen source on the mycelial growth rate of the pathogen during a 5-day culture period, and explored the lethal temperature. The results showed that the mycelia grew well under the photoperiod of 12 h light/12 h darkness, at 5-40 ℃(optimal temperature: 25 ℃), at pH 4-11(optimal pH: 7.0), on a variety of media(optimal medium: oatmeal agar), and in the presence of diverse carbon and nitrogen sources(optimal carbon source: soluble starch; optimal nitrogen source: sodium nitrate). The lethal temperature was verified to be 51 ℃(10 min). The conclusion is expected to lay a scientific basis for diagnosis and control of R. glutinosa leaf diseases caused by F. acuminatum.
Carbon ; Nitrogen ; Phylogeny ; Rehmannia

OBJECTIVETo provide theoretical evidences for the identification and selective breeding of different major varieties of Rehmannia glutinosa by comparing their leaf characters such as the shapes, non-glandular hairs and the size and density of stomata.

METHODThe length, width and the ratio of the length to the width of leaves were measured, and the density and length of the non-glandular hair, the density, size and density of the stomata in the epidermis were measured by scanning electron microscope.

RESULTThe results showed that there were obvious differences in length, width and the ratio of the length to the width of leaves, the density and length of the non-glandular hair, the density and size of the stomata in the epidermis.

CONCLUSIONThe morphological characters of the leaves mentioned above may serve as the identification standards of major varieties of R. glutinosa.

This study aims to acetylate Rehmannia glutinosa polysaccharides by acetic anhydride method, optimize process parameters and evaluate their antioxidant activity. With the degree of substitution(D_s) as a criterion, the effects of reaction time, acetic anhydride-to-polysaccharides ratio and temperature were investigated. Process parameters were optimized by single-factor experiment and response surface methodology. The infrared spectroscopy(IR) and scanning electron microscopy(SEM) proved the successful acetylation and were employed to preliminarily analyze the structural characteristics of acetylated derivatives. The results showed that the D_s was 0.327 under the optimal technological conditions, including m(acetic anhydride):m(R. glutinosa polysaccharides)=2.70, reaction time 3.0 h and temperature 48 ℃. Further, the antioxidant properties of acetylated derivatives were investigated in vitro and acetylation was found effective to improve the antioxidant activity of R. glutinosa polysaccharides. This study provides a reference for the further development and application of R. glutinosa polysaccharides.
Acetylation ; Antioxidants/pharmacology* ; Polysaccharides/pharmacology* ; Rehmannia/chemistry*

The history of Rehmannia glutinosa breeding has already beyond 100 years. There are rich cultivated varieties and wild germplasm resources in R. glutinosa. However, there also exist a lot of problems, such as, the pedigree of the existing varieties is not clear, the genetic basis is narrow, backward method of germplasm enhancement and breeding. Breeding of new varieties has been unable to meet the demand of R. glutinosa production in the new era. This paper summarizes the species of Rehmannia and their distribution, the diversity of plant morphology and the quality of R. glutinosa germplasm resources, as well as the progress of R. glutinosa breeding in recent 100 years. For ensuring the orderly, effective and safe production of R. glutinosa, the authors suggest to establish the wild resources protection area and germplasm resources garden, deeply study the genetic base of quality, strengthen application of new breeding method such as mutation breeding, haploid breeding and gene editing.
Plant Breeding ; Plants, Medicinal ; genetics ; Rehmannia ; genetics

OBJECTIVETo explore effects on allelopathic autotoxicity of Rehmannia glutinosa of different abatement measures.

METHODThe experiments for abating allelopathic effects of R. glutinosa were designed with the reducing rate as a indication, three measures of the treating soil with lime nitrogen, and water washing were employed, R. glutinosa- Achyranthes bidentata rotation system and using Achyranthes bidentata as green manure, and seedling transplant were also studied for the abatement effect.

RESULTEffect of seedling transplant was the best, reducing rate of transplant and bare root transplant on the 20th day after emergence was 76.80%, 71.70%, respectively. The reducing rate of the treating soil with microorganism reached 54.25%. The effects of water washing and R. glutinosa-A. bidentata rotation system and using A. bidentata as green manure were not satisfied. Especially only using A. bidentata as green manure without rotation system worsened the allelopathic effects of R. glutinosa.

CONCLUSIONAll measures can abate allelopathic effects of R. glutinosa to some extent except only using A. bidentata as green manure.

OBJECTIVETo study the effect of seedling quality on growth, yield and quality of Rehmannia glutinosa at harvest and build a basis for its GAP.

METHODThe seedling quality of R. glutinosa in main producing regions was surveyed to understand the current status of seedling quality. Field experiments with different varieties and seedling quality were conducted to measure dry matter accumulation with different growth of R. glutinosa and oligosaccharide content, and economic yield at harvest.

RESULTThe seedling was randomly selected by farmers in R. glutinosa producing regions. Seedling quality could significantly improve on seedling emergence rate, and promote seedling growth, especially with early stage R. glutinosa, finally increase yield at harvest. At harvest, 63% and 50% of yield with A and B seedling could be improved for variety of 85-5, and 50% and 47% of yield could be increased for variety of Beijing No. 1, compared to the C seeding.

CONCLUSIONIn cultivation, the seedlings with the diameter > 1.5 cm should be transplanted firstly.

Root rot was occurred widely in the production area of Rehmannia glutinosa, and which result in serious influence on the yield and quality of R. glutinosa. In the present work, a new phytopathogen was isolated from roots with root rot symptom in the production area of R. glutinosa. The colony of the pathogen growing on PDA medium was gray-black, the structure of hyphae was compact, the aerial hyphae was less developed, and the back of the colony was black. The hyphae of the pathogen were uneven in size, about 2 to 3 μm in diameter and twined with each other, the conidia of the pathogen were small, nearly round and about 1 μm in diameter. The healthy roots of R. glutinosa were inoculated with the pathogen in vitro, black-brown rot was observed at the inoculate sites after a few days' incubation. The rhizosphere soil of healthy R. glutinosa seedlings were inoculated in vivo, the leaves were wilted and the roots were black-brown rotted after several days' normal culture, the symptoms were consistent with those observed in the field. The genomic DNA of the pathogen was amplified by fungus rDNA-ITS universal primer ITS1/ITS4 and homologous analyzed, the pathogen was in a branch with Heterophoma sp., Phoma sp., P. novae-verbascicola and P. herbarum with the nuclear acid homology of 99.21% to 99.43%. The pathogen shown 97.00% to 98.02% nuclear acid homology with H. verbascicola, H. novae-verbascicola, H. poolensis, P. herbarum, H. sylvatica, H. verbascicola and H. verbasci-densiflori when amplified by the tub2 gene special primer Btub2 fd/Btub4 rd, and H. novae-verbascicola was the highest. The pathogen was in a branch with H. novae-verbascicola when amplified by the lsu gene special primer LR0 R/LR7. Based on the morphological characteristics, nucleotide sequence analysis and Koch's test results, the isolated pathogen causing root rot of R. glutinosa was identified as H. novae-verbascicola. This study is of great significance for the further theoretical research on root rot of R. glutinosa and root rot control in field.
DNA, Ribosomal ; Fungi/genetics* ; Plant Leaves ; Rehmannia/genetics* ; Seedlings

With the rice-steamed Rehmanniae Radix unearthed from the tomb of Haihunhou in the Western Han Dynasty as the re-ference, the present study evaluated the quality of Rehmanniae Radix and investigated the processing technology of rice-steamed Rehmanniae Radix to lay the foundation for the research on rice-steamed Rehmanniae Radix products. With catalpol and rehmannioside D as the investigation indexes, the quality and grade of Rehmanniae Radix from different producing areas were evaluated with the methods in 2020 edition of Chinese Pharmacopoeia. UPLC method was established for the determination of catalpol and rehmannioside D in the rice-steamed Rehmanniae Radix. The effects of steaming time, the amount of supplementary rice, and steaming times in the rice-steamed processing on the quality of products were investigated by L_9(3~4) orthogonal test and multi-index comprehensive balance scoring method combined with the content of catalpol and rehmannioside D and appearance characteristics. At last, the stability of the processing technology was tested. The results showed that the optimal processing technology for rice-steamed Rehmanniae Radix was as follows: Rehmanniae Radix and rice(200 g∶4 g) were steamed twice at atmospheric pressure, four hours each time. The mass fractions of catalpol and rehmannioside D were 0.184% and 0.335%, respectively, and the character score was 6.5. The processing conditions are reaso-nable, stable, and feasible. It can provide a basis for the restoration of the ancient rice-steamed processing technology and references for the development of rice-steamed Rehmanniae Radix products in the future.
Drugs, Chinese Herbal/pharmacology* ; Oryza ; Plant Extracts ; Rehmannia ; Technology

The consecutive monoculture obstacle is a major problem in the field of Rehmannia glutinosa( R. glutinosa),has severely declined the yield and quality of R. glutinosa. Here,using hi TAIL-PCR and RACE techniques,we have cloned the full-length transcript( 1 573 bp) of Unigene 29334＿All screened by DGE as a consecutive monoculture obstacle response gene of R. glutinosa. Based on ORF Finder prediction,all ORFs detected in the full-length transcript were less than 300 nt,which suggested that the above transcript was confirmed to be a long non-coding RNA( LncRNA). With alignment in R. glutinosa transcriptome,this LncRNA was partially homologous to alanine glyoxylate transaminase 2 gene( Rg AGT2),which was named LncRNA-RgATG2. To further explore the function of LncRNA-RgAGT2,we have examined expression patterns of LncRNA-RgAGT2 and Rg AGT2 at five critical development stages( seedling,elongation,pre-expanding,mid-expanding,late-expanding) in the first and second year replanting of R. glutinosa,respectively. The results indicated that LncRNA-RgAGT2,as a potential regulator,is possible to play a vital role in Rg AGT2 expression regulation. Meanwhile,LncRNA-RgAGT2 has presented significant variation in all development stages of R. glutinosa,which could be used as a " diagnostic label" to assess consecutive monoculture obstacle. This study,for the first time,showed that LncRNA was responsible for the response and regulation of consecutive monoculture obstacle,which would be a powerful supplement to reveal the molecular mechanisms of consecutive monoculture obstacle of R. glutinosa.
Cloning, Molecular ; Gene Expression ; RNA, Long Noncoding ; Rehmannia ; Transcriptome