Yanqin Xu

Oriental orchids possess great potential in the consumer market because of their diverse leaf and flower patterns and enchanting fragrance. Nevertheless, their long growth period, stringent growth environment requirements, low germination rates, and limited transformation methods pose significant obstacles to genetic improvement. To improve the regeneration efficiency of oriental orchids and enhance their transformation efficiency, the solid–liquid oscillation–solid alternating cultivation mode was used to efficiently obtain stable transformants of Cymbidium orchids in this study. The results showed that within approximately 2 months, the regeneration rate of C. goeringii derived from protocorm-like bodies reached a remarkable 77.30% with this method. The transformation efficiency of C. goeringii achieved through polymerase chain reaction amplification was 18.66% when inoculated with Agrobacterium LBA4404, and the positive transformation rate reached 75.03%. This experimental result was further validated by β-glucuronidase staining and green fluorescent protein fluorescence detection. This methodology significantly increased the positive transformation rate and shortened the regeneration period of C. goeringii . Furthermore, this cultivation mode was successfully implemented for C. faberi and C. ensifolium . Therefore, the solid–liquid oscillation–solid alternating cultivation mode provides a technical basis for efficient transformation, which will promote the rapid development of genetically improved oriental orchids.

Portulaca oleracea L. is an important herb with the same origin in medicine and food. To achieve the precise sowing of P. oleracea, this study employed a mixed experimental design to optimize the pellet formulation of the seeds. Fillers such as kaolin, bentonite, and talcum powder were used, along with binders including polyvinyl alcohol, sodium alginate, and sodium carboxymethyl cellulose. The physical characteristics and germination properties of the pelletized seeds were evaluated to determine the optimal formulation. The results indicated that, after pelletizing, the seeds exhibited a higher seed viability and vigor, germination rate, and germination index. Specifically, the seed singulation rate correlated positively with the kaolin content, the disintegration rate was proportional to the amount of talcum powder added, and the compression resistance was positively correlated with the bentonite ratio. Using response optimization, the optimal formulation of fillers used for pelletizing P. oleracea seeds was identified as 17% talcum powder, 16% kaolin, and 67% bentonite. Single-factor experiments showed that using PVP as a binder at a mass fraction of 10% resulted in improved pelletizing indices. This study not only optimized the pelletizing formulation of P. oleracea seeds based on physical and germination properties, but also expanded the application of pelletizing in the processing of the seeds of traditional Chinese herbs. It holds significant implications for the mechanized production of small, pelletized seeds of traditional Chinese herbs.

Plant cis-regulatory sequences (CRSs) are essential for gene expression and transcriptional regulation in plants. With the rapid development of plant biotechnologies, such as transgenesis and gene editing tools, plant-derived CRSs have gradually replaced traditional CRSs, like the 35S promoter, to avoid some negative effects caused by exogenous DNA sequences. In this study, we provided a comprehensive analysis of the published genomic data of Andrographis paniculata and identified six candidate ApACRs. Based on the transient assays, two candidate CRSs (ApACR1 and ApACR2) demonstrated high transcriptional activities comparable to those of the 35S promoter in several plant species, in contrast to others with lower activities, suggesting their further potential applications in plant biotechnology and genetic engineering.

Epimedium sagittatum (Sieb. et Zucc.) Maxim. (ESM) which accumulates several principal flavonoid compounds including epimedin A, B, C and icariin, is extensively utilized in traditional herbs for sexual dysfunction, osteoporosis etc. In China, ESM has a wealth of wild plant resources and characterized by significant variability in medicinal compounds accumulation. Understanding the diversity of ESMs can lead to better utilization of these plant resources. In this study, we integrated the metabolomic and transcriptomic analysis of three ESMs that originated in Anhui, Hubei and Jiangxi in China. Results showed that the flavonoid biosynthesis as well as the related gene expression in these ESMs revealed substantial differences. For example, the epimedin A, B, C and icariin as well as some related gene expression in ESMs from Anhui are significantly lower than those of in others. These results suggested that the ESMs from wild population without quality checkout may not be suitable for directly use as the materials for preparation of Chinese medicine and ESMs with different accumulation of metabolites could be used for distinct applications.

Rubus chingii Hu is the only species that is used for both edible and medicinal purposes among the 194 species of the genus Rubus in China. It is well known for its sweet and sour fresh fruits that are rich in vitamins and for its dried immature fruits that are used to treat kidney-related ailments. This study aims to evaluate genetic diversity and population structure and build a core germplasm repository of 132 R. chingii accessions from the provinces of Jiangxi and Fujian, using Hyper-seq-derived single-nucleotide polymorphism (SNP) markers. This is the first genetic study of R. chingii based on SNP molecular markers, and a total of 1,303,850 SNPs and 433,159 insertions/deletions (InDels) were identified. Low values for observed heterozygosity, nucleotide diversity (Pi) and fixation indexes (Fis) indicated low genetic diversity within populations, and an analysis of molecular variance (AMOVA) showed that 37.4% and 62.6% of the variations were found between populations and within samples, respectively. Four main clusters were identified by means of neighbor-joining (NJ) trees, the ADMIXTURE program and principal component analysis (PCA). Based on the genetic diversity, we finally constructed 38 representative core collections, representing 50% of the total core germplasm samples and 95.3% of the genotypes. In summary, the results of our study can provide valuable information on the genetic structure of R. chingii germplasm resources, which is helpful for further explorations of potential high-quality genes and for formulating future breeding and conservation strategies.

Water chestnut (Trapa L.) is a floating-leaved aquatic plant with high edible and medicinal value. In this study, we presented chromosome-level genome assemblies of cultivated large-seed species Trapa bicornis and its wild small-seed relative Trapa incisa by using PacBio HiFi long reads and Hi-C technology. The T. bicornis and T. incisa assemblies consisted of 479.90 Mb and 463.97 Mb contigs with N50 values of 13.52 Mb and 13.77 Mb, respectively, and repeat contents of 62.88% and 62.49%, respectively. A total of 33,306 and 33,315 protein-coding genes were predicted in T. bicornis and T. incisa assemblies, respectively. There were 159,232 structural variants affecting more than 11 thousand genes detected between the two genomes. The phylogenetic analysis indicated that the lineage leading to Trapa was diverged from the lineage to Sonneratia approximately 23 million years ago. These two assemblies provide valuable resources for future evolutionary and functional genomic research and molecular breeding of water chestnut.

Two quality control standards, total flavonoid glycosides of Epimedii Folium and epimedin C of Epimedii Wushanensis Folium, were used to systematically evaluate the quality of Epimedium wushanense T. S. Ying, so as to provide reference for its germplasm screening and resource utilization. Seven representative populations of E. wushanense covering its main distribution areas were uniformly sampled during the flowering period. There were significant quality differences among the populations of E. wushanense. According to the quality standard of total flavonoid glycosides, all populations were superior to the quality standard of the Chinese Pharmacopoeia for Epimedii Folium, with more than 1.5 % total flavonoid glycosides. The variation ranges of epimedin A, epimedin B, epimedin C, icariin and total flavonoid glycosides were 0.40–0.76 %, 0.51–0.83 %, 1.70–9.31 %, 0.40–1.23 % and 3.05–10.61 %, respectively. According to the quality standard of epimedin C, all populations were better than the quality standard of the Chinese Pharmacopoeia for Epimedii Wushanensis Folium, with more than 1.0 % epimedin C. The variation range of epimedin C was 2.22–10.06 %. When comparing the results of the two methods, a trend of slightly lower mean values was found for total flavonoid glycosides, except for the HBXW population. The quality of E. wushanense was superior to both the quality standard of Epimedii Folium and Epimedii Wushanense Folium in the Chinese Pharmacopoeia. Epimedin C was the most abundant component. Among the investigated populations, HBXW and HBGK exhibited the highest quality, and may provide excellent genetic resources for standardized cultivation. In addition, the habitat of these populations can also serve a reference for cultivation conditions.

Both Epimedium sutchuenense Franch. 1894 and E. fargesii Franch. 1894 are perennial herbs with excellent ornamental values due to their showy flowers. However, little molecular research has been done on these species. Here, the complete chloroplast (cp) genome of E. sutchuenense and E. fargesii was analyzed and reported. The cp genome sizes of E. sutchuenense and E. fargesii were 157, 263 and 157, 133 bp, respectively. Both the two cp genomes contained a pair of inverted repeat regions (IRs) (25,782 and 25,796 bp), separated by the small single-copy (SSC) region (17,106 and 17,071 bp) and a large single-copy (LSC) region (88,593 and 88,470 bp). A total of 113 unique genes were annotated in each of the two cp genomes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic analysis supported a close relationship between E. sutchuenense and E. wushanense, while E. fargesii had no clear clustering branch.