Dendrobium officinale is an important traditional Chinese medicinal plant and crop, which contains many kinds of medicinal components. The quality of medicinal plants is closely related to the ecological factors in a growing environment. The main components of D. officinale determined in this study were polysaccharides, total alkaloids and total flavonoids. In addition, this study dealt with the correlation of these components to 16 ecological factors under three different cultivation modes (Greenhouse, Bionic, Wild; Lu’an, Anhui Province, China). The relationship between ecological factors and quality factors was analyzed step by step using correlation analysis, principal component analysis and stepwise multiple linear regression. Eight ecological factors: maximum relative humidity, minimum relative humidity, maximum temperature, sunshine duration, soil pH, soil total nitrogen, soil total phosphorus and soil available phosphorus were considered as key factors that influenced the main medicinal qualities of cultivated D. officinale. This study provides an insight for exploring the complex relationship between ecological factors and D. officinale medicinal value in artificial cultivation.

Dendrobium officinale is a Chinese herbal medicine with a long history of use in China. Flavonoids are known to be an important secondary metabolite in Dendrobium officinale, but very little is known about their molecular regulation mechanism in D. officinale. In this study, we collected one to four years old D. officinale stems for the purpose of RNA-sequencing and mass spectrometry data collection. The results showed that metabolome analysis detected 124 different flavonoid metabolites of which flavonol metabolites were significantly increased in biennial samples. In the transcriptome analysis, 30 different genes involved in the synthesis of flavonoid were identified. The key genes FLS (LOC110101392, LOC110107557, LOC110114894) that regulate the synthesis of flavonols are highly expressed in biennial samples. The present study contributes a new insight into the molecular mechanism of flavonoid accumulation in D. officinale.

Background: Dendrobiumis a precious herbal that belongs to Orchidaceae and is widely used as health care traditional Chinese medicine in Asia. Although orchids are mycorrhizal plants, most research still focuses on endophytes, and there is still large amount unknown about rhizosphere microorganisms. To investigate the rhizosphere microbial community of differentDendrobiumspecies during the maturity stage, we used high-throughput sequencing to analyze microbial community in rhizosphere soil during the maturity stage of three kinds ofDendrobiumspecies.Results: In our study, a total of 240,320 sequences and 11,179 OTUs were obtained from these threeDendrobiumspecies. According to the analysis of OTU annotation results, differentDendrobiumrhizosphere soil bacteria include 2 kingdoms, 63 phyla, 72 classes, 159 orders, 309 families, 850 genera and 663 species. Among all sequences, the dominant bacterial phyla (relative abundance > 1%) were Proteobacteria, Actinobacteria, Bacteroidetes, Acidobacteria, Firmicutes, Verrucomicrobia, Planctomycetes, Chloroflexi, and Gemmatimonadetes. And through WGCNA analysis, we found the hub flora was also belong to Acidobacteria, Actinobacteria and Proteobacteria.Conclusions: We found that the rhizosphere bacterial communities of the three kinds ofDendrobiumhave significant differences, and that the main species of rhizosphere microorganisms ofDendrobiumare concentrated in the Proteobacteria, Actinobacteria, and Bacteroidetes. Moreover, the smaller the bacterial level, the greater the difference amongDendrobiumspecies. These results fill knowledge gaps in the rhizosphere microbial community ofDendrobiumand provide a theoretical basis for the subsequent mining of microbial functions and the study of biological fertilizers.

Dendrobium huoshanense is both a traditional herbal medicine and a plant of high ornamental and medicinal value. We used transcriptomics and metabolomics to investigate the effects of growth year on the secondary metabolites of D. huoshanense stems obtained from four different years of cultivation. In this study, a total of 428 differentially accumulated metabolites (DAMs) and 1802 differentially expressed genes (DEGs) were identified. The KEGG enrichment analysis of DEGs and DAMs revealed significant differences in “Flavonoid biosynthesis”, “Phenylpropanoid biosynthesis” and “Flavone and flavonol biosynthesis”. We summarize the biosynthesis pathway of flavonoids in D. huoshanense, providing new insights into the biosynthesis and regulation mechanisms of flavonoids in D. huoshanense. Additionally, we identified two candidate genes, FLS (LOC110107557) and F3’H (LOC110095936), which are highly involved in flavonoid biosynthesis pathway, by WGCNA analysis. The aim of this study is to investigate the effects of growth year on secondarily metabolites in the plant and provide a theoretical basis for determining a reasonable harvesting period for D. huoshanense.

Arbuscular mycorrhizal fungi (AMF) play an important role in the establishment and maintenance of plant communities in forest ecosystems. Most previous studies about AMF have been conducted in natural forests, and little attention has been paid to trees in planted forests. This study investigated AMF associated with tree species and the relationships between edaphic factors and AMF communities in a planted forest of eastern China. We found high total AMF colonization rates in the roots of Carya illinoensis (Wangenh.) K. Koch, Zelkova serrata (Thunb.) Makinoz, Taxodium ‘zhongshansha’, Eucommia ulmoides Oliv., and Elaeagnus pungens Thunb., ranging from 62.07% to 100%, indicating that AMF can establish effective symbiotic relationships with these tree species. The AMF colonization rate was significantly and negatively correlated with soil phosphorus, while AMF colonization intensity was significantly and negatively correlated with soil moisture content, total carbon, and organic matter content. Spore density was in the range of 4.38 to 76.38 spores per g soil. In total, 35 AMF species from 10 genera were identified. Glomus and Acaulospora were the dominant genera. Acaulospora foveata and Septoglomus constrictum were the dominant species. AMF communities differed among the tree species and were closely related to edaphic factors, and AMF diversity was significantly related to soil carbon and pH. Our results revealed the colonization, community, and diversity of AMF associated with tree species, as well as their relationships with edaphic factors, in planted forests. Our findings can be used to provide insight on the utilization and management of AMF to maintain sustainable management of planted forests.