Genetic diversity and population structure of endangered Glehnia littoralis (Apiaceae) in China based on AFLP analysis

Cytological analysis of flower development, insights into suitable growth area and genomic background: implications for Glehnia littoralis conservation and sustainable utilization

BACKGROUND

Glehnia littoralis F. Schmidt ex Miq., an endangered plant species with significant medicinal, edible, and ecological value, is now a central concern for conservation and sustainable utilization. Investigating the physiological and ecological mechanisms leading to its endangerment and elucidating its genetic background constitutes the foundation for conducting in-depth research on G. littoralis.

RESULTS

Our observations have revealed a significant degree of floral sterility in wild populations of G. littoralis. The inflorescences of G. littoralis are classified into three types: completely fertile, completely sterile, and partially fertile compound umbels. Moreover, the flowers of G. littoralis can be categorized into fertile and sterile types. Sterile flowers exhibited abnormalities in the stigma, ovary, and ovules. This study is the first to discover that the presence or absence of a giant cell at the funiculus during the initiation of ovule primordium determines whether the flower can develop normally, providing cytological evidence for female sterility in G. littoralis. Conversely, both fertile and sterile flowers produced normally developed pollen. Field observations have suggested that robust plants bear more fertile umbels, while weaker ones have fewer or even no fertile umbels, indicating a close relationship between flower fertility and plant nutritional status. Our model correctly predicted that the eastern coastal regions of China, as well as prospective areas in Neimenggu and Sichuan, are suitable environments for its cultivation. Additionally, Using flow cytometry and genome survey, we estimated the genome size of G. littoralis to be 3.06 Gb and the heterozygosity to be 4.58%.

CONCLUSION

The observations and findings presented in this study were expected to provide valuable insights for further conserving its genetic resources and sustainable utilization of G. littoralis.

A single origin and high genetic diversity of cultivated medicinal herb Glehnia littoralis subsp. littoralis (Apiaceae) deciphered by SSR marker and phenotypic analysis

Ten SSR markers based on transcriptome sequencing were employed to genotype 231 samples of G. littoralis subsp. littoralis (Apiaceae) from nine cultivated populations and seven wild populations, aiming to assess the genetic diversity and genetic structure, and elucidate the origin of the cultivated populations. Cultivated populations exhibited relatively high genetic diversity (h = 0.441, I = 0.877), slightly lower than that of their wild counterparts (h = 0.491, I = 0.930), likely due to recent domestication and ongoing gene flow between wild and cultivated germplasm. The primary cultivated population in Shandong have the crucial genetic status. A single origin of domestication was inferred through multiple analysis, and wild populations from Liaoning and Shandong are inferred to be potentially the ancestor source for the present cultivated populations. Phenotypic analysis revealed a relatively high heritability of root length across three growth periods (0.683, 0.284, 0.402), with significant correlations observed between root length and petiole length (Pearson correlation coefficient = 0.30, P<0.05), as well as between root diameter and leaf area (Pearson correlation coefficient = 0.36, P<0.01). These parameters can serve as valuable indicators for monitoring the developmental progress of medicinal plants during field management. In summary, this study can shed light on the intricate genetic landscape of G. littoralis subsp. littoralis, providing foundational insights crucial for conservation strategies, targeted breeding initiatives, and sustainable management practices in both agricultural and natural habitats.

Sporogenesis, gametophyte development and embryogenesis in Glehnia littoralis

BACKGROUND

Glehnia littoralis is an economic herb with both medicinal and edible uses. It also has important ecological value and special phylogenetic status as it is a monotypic genus species distributing around beach. Little information on its reproductive biology has been reported so far, which has hindered conservation and application of this species. In this study, we observed morphological changes from buds emergence to seeds formation and internal changes during sporogenesis, gametophyte development and embryo and endosperm development of G. littoralis using paraffin-embedded-sectioning and stereo microscope.

RESULTS

The results showed that the stages of internal development events of G. littoralis corresponded to obvious external morphological changes, most of developmental features were consistent with other Apiaceae species. The development of male and female gametophytes was not synchronized in the same flower, however, exhibited temporal overlap. From mid-late April to mid-May, the anther primordial and ovule primordial developed into the trinucleate pollen grain and eight-nuclear embryo sac, respectively. From late-May to mid-July, the zygote developed into mature embryo. In addition, some defects in gynoecium or ovule development and abnormal embryo and endosperm development were found. We induced that the possible causes of abortion in G. littoralis were as follows: nutrient limitation, poor pollination and fertilization, and bad weather.

CONCLUSIONS

This study revealed the whole process and morphological characteristics of the development of reproductive organ in G. littoralis, which not only provided important data for the study of systematic and conservation biology, but also provided a theoretical basis for cross breeding.

Domestication Potential of Garcinia kola Heckel (Clusiaceae): Searching for Diversity in South Cameroon

Seeds and bark of Garcinia kola Heckel (Clusiaceae) are popular products in West and Central Africa. Despite the tree's economic and cultural importance, little is known about its phenotypic and genotypic variation. This study characterised the morphological and genetic diversity of G. kola in South Cameroon, searching for traits and populations that might be used for domestication. Morphological assessment and amplified fragment length polymorphism (AFLP) markers were applied to characterise diversity among geographic populations from Central and South regions, and between managed and wild trees. AFLP-SURV and analysis of molecular variance results indicated that a major part of genetic diversity is harboured within populations rather than between them. Bayesian analysis, principal component analysis and t-SNE identified three clusters where Ebolowa emerged as the transition population, combining features from both regions. Trees from the south had a higher prevalence of morphological domestication-related characteristics. Trees from the central region, on the other hand, demonstrated greater genetic diversity. No significant differences in phenotype and genotype were revealed between wild and managed populations, suggesting G. kola is still in the early stages of its domestication process.

Genetic Diversity and Population Dynamics of Leptobrachium leishanense (Anura: Megophryidae) as Determined by Tetranucleotide Microsatellite Markers Developed from Its Genome

Persisting declination of amphibians around the world has resulted in the public attaching importance to the conservation of their biodiversity. Genetic data can be greatly helpful in conservation planning and management, especially in species that are small in size and hard to observe. It is essential to perform genetic assessments for the conservation of Leptobrachium leishanense, an endangered toad and receiving secondary protection on the list of state-protected wildlife in China. However, current molecular markers with low reliability and efficiency hinder studies. Here, we sampled 120 adult toes from the population in the Leishan Mountain, 23 of which were used to develop tetranucleotide microsatellite markers based on one reference L. leishanense genome. After primer optimization, stability detection, and polymorphism detection, we obtained 12 satisfactory microsatellite loci. Then, we used these loci to evaluate the genetic diversity and population dynamics of the 120 individuals. Our results show that there is a low degree of inbreeding in the population, and it has a high genetic diversity. Recently, the population has not experienced population bottlenecks, and the estimated effective population size was 424.3. Accordingly, stabilizing genetic diversity will be key to population sustainability. Recovering its habitat and avoiding intentional human use will be useful for conservation of this species.

Amplified Fragment Length Polymorphism: Applications and Recent Developments

AFLP or amplified fragment length polymorphism is a PCR-based molecular technique that uses selective amplification of a subset of digested DNA fragments from any source to generate and compare unique fingerprints of genomes. It is more efficient in terms of time, economy, reproducibility, informativeness, resolution, and sensitivity, compared to other popular DNA markers. Besides, it requires very small quantities of DNA and no prior genome information. This technique is widely used in plants for taxonomy, genetic diversity, phylogenetic analysis, construction of high-resolution genetic maps, and positional cloning of genes, to determine relatedness among cultivars and varietal identity, etc. The review encompasses in detail the various applications of AFLP in plants and the major advantages and disadvantages. The review also considers various modifications of this technique and novel developments in detection of polymorphism. A wet-lab protocol is also provided.