Allozyme diversity and population genetic structure of three medicinal Epimedium species from Hubei

Parallel evolution, atavism, and extensive introgression explain the radiation of Epimedium sect. Diphyllon (Berberidaceae) in southern East Asia

East Asia is the richest region of plant biodiversity in the northern temperate zone, and its radiation provides key insights for understanding rapid speciation, including evolutionary patterns and processes. However, it is challenging to investigate the recent evolutionary radiation among plants because of the lack of genetic divergence, phenotypic convergence, and interspecific gene flow. Epimedium sect. Diphyllon is a rarely studied plant lineage endemic to East Asia, especially highly diversified in its southern part. In this study, we report a robust phylogenomic analysis based on genotyping-by-sequencing data of this lineage. The results revealed a clear biogeographic pattern for Epimedium sect. Diphyllon with recognition into two major clades corresponding to the Sino-Himalayan and Sino-Japanese subkingdoms of East Asian Flora and rapid diversification of the extant species dated to the Pleistocene. Evolutionary radiation of Epimedium sect. Diphyllon is characterized by recent and predominant parallel evolution and atavism between the two subkingdom regions, with extensive reticulating hybridization within each region during the course of diversification in southern East Asia. A parallel-atavism-introgression hypothesis is referred to in explaining the radiation of plant diversity in southern East Asia, which represents a potential model for the rapid diversification of plants under global climate cooling in the late Tertiary. Our study advances our understanding of the evolutionary processes of plant radiation in East Asia as well as in other biodiversity hotspot regions.

Construction of the first high-density genetic linkage map and QTL mapping of flavonoid and leaf-size related traits in Epimedium

BACKGROUND

Leaves are the main medicinal organ in Epimedium herbs, and leaf flavonoid content is an important criterion of Epimedium herbs. However, the underlying genes that regulate leaf size and flavonoid content are unclear, which limits the use of breeding for Epimedium development. This study focuses on QTL mapping of flavonoid and leaf-size related traits in Epimedium.

RESULTS

We constructed the first high-density genetic map (HDGM) using 109 F1 hybrids of Epimedium leptorrhizum and Epimedium sagittatum over three years (2019-2021). Using 5,271 single nucleotide polymorphism (SNP) markers, an HDGM with an overall distance of 2,366.07 cM and a mean gap of 0.612 cM was generated by utilizing genotyping by sequencing (GBS) technology. Every year for three years, 46 stable quantitative trait loci (QTLs) for leaf size and flavonoid contents were discovered, including 31 stable loci for Epimedin C (EC), one stable locus for total flavone content (TFC), 12 stable loci for leaf length (LL), and two stable loci for leaf area (LA). For flavonoid content and leaf size, the phenotypic variance explained for these loci varied between 4.00 and 16.80% and 14.95 and 17.34%, respectively.

CONCLUSIONS

Forty-six stable QTLs for leaf size and flavonoid content traits were repeatedly detected over three years. The HDGM and stable QTLs are laying the basis for breeding and gene investigation in Epimedium and will contribute to accelerating the identification of desirable genotypes for Epimedium breeding.

The growth and medicinal quality of Epimedium wushanense are improved by an isolate of dark septate fungus

CONTEXT

Seven dark-septate endophytic (DSE) fungi have been isolated from the roots of Epimedium wushanense T. S. Ying (Berberidaceae), an important medicinal plant with various pharmacological activities.

OBJECTIVE

The current study explores the effects of seven DSE fungi on the growth and accumulation of bioactive compounds in E. wushanense.

MATERIALS AND METHODS

Each 1-month-old E. wushanense seedling was inoculated with one of the seven DSE fungi and was grown under greenhouse conditions for 90 d. The molecular identification of the fungi was based on the ITS1-5.8S-ITS2 nuclear ribosomal gene cluster.

RESULTS

The results showed that the influence of DSE fungi inoculation varied between strains. Inoculation with DSE8 not only significantly enhanced plant height, root length, leaf area, leaf number, and shoot and root biomass but also improved the total flavonoid and icariin content, with an increase ranging from 20.24% to 237.97%. Three of the seven DSE fungi caused the inoculated plants to die, and the remaining three DSE strains showed neutral or negative effects on plant growth and the accumulation of bioactive compounds. According to the ITS sequence, DSE8 is congeneric to the genus Leptodontidium.

DISCUSSION AND CONCLUSION

The findings indicate that application of DSE8 may be valuable to facilitate the cultivation of E. wushanense with a higher biomass and improved medicinal quality.

Fourteen microsatellite loci for the Chinese medicinal plant Epimedium sagittatum and cross-species application in other medicinal species

Epimedium sagittatum is a well-known medicinal plant as well as potential ground cover and ornamental plant. A total of 14 polymorphic microsatellite markers were developed for use in taxonomy, phylogenetics and conservation genetics. Markers were presented between two and eight alleles per locus. The observed heterozygosity (H(O) ) and expected heterozygosity (H(E) ) ranged from 0.03 to 0.81 and from 0.05 to 0.81, respectively. Cross-amplification among other four medicinal species revealed promising results in three to six polymorphic loci. These microsatellite loci contributed to the limited number of useful markers currently available for E. sagittatum.

Development of a EST dataset and characterization of EST-SSRs in a traditional Chinese medicinal plant, Epimedium sagittatum (Sieb. Et Zucc.) Maxim

Background

Epimedium sagittatum (Sieb. Et Zucc.) Maxim, a traditional Chinese medicinal plant species, has been used extensively as genuine medicinal materials. Certain Epimedium species are endangered due to commercial overexploition, while sustainable application studies, conservation genetics, systematics, and marker-assisted selection (MAS) of Epimedium is less-studied due to the lack of molecular markers. Here, we report a set of expressed sequence tags (ESTs) and simple sequence repeats (SSRs) identified in these ESTs for E. sagittatum.

Results

cDNAs of E. sagittatum are sequenced using 454 GS-FLX pyrosequencing technology. The raw reads are cleaned and assembled into a total of 76,459 consensus sequences comprising of 17,231 contigs and 59,228 singlets. About 38.5% (29,466) of the consensus sequences significantly match to the non-redundant protein database (E-value < 1e-10), 22,295 of which are further annotated using Gene Ontology (GO) terms. A total of 2,810 EST-SSRs is identified from the Epimedium EST dataset. Trinucleotide SSR is the dominant repeat type (55.2%) followed by dinucleotide (30.4%), tetranuleotide (7.3%), hexanucleotide (4.9%), and pentanucleotide (2.2%) SSR. The dominant repeat motif is AAG/CTT (23.6%) followed by AG/CT (19.3%), ACC/GGT (11.1%), AT/AT (7.5%), and AAC/GTT (5.9%). Thirty-two SSR-ESTs are randomly selected and primer pairs are synthesized for testing the transferability across 52 Epimedium species. Eighteen primer pairs (85.7%) could be successfully transferred to Epimedium species and sixteen of those show high genetic diversity with 0.35 of observed heterozygosity (Ho) and 0.65 of expected heterozygosity (He) and high number of alleles per locus (11.9).

Conclusion

A large EST dataset with a total of 76,459 consensus sequences is generated, aiming to provide sequence information for deciphering secondary metabolism, especially for flavonoid pathway in Epimedium. A total of 2,810 EST-SSRs is identified from EST dataset and ~1580 EST-SSR markers are transferable. E. sagittatum EST-SSR transferability to the major Epimedium germplasm is up to 85.7%. Therefore, this EST dataset and EST-SSRs will be a powerful resource for further studies such as taxonomy, molecular breeding, genetics, genomics, and secondary metabolism in Epimedium species.