scholarly journals Genome-Wide Diversity Analysis of Valeriana officinalis L. Using DArT-seq Derived SNP Markers

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1346
Author(s):  
Maja Boczkowska ◽  
Katarzyna Bączek ◽  
Olga Kosakowska ◽  
Anna Rucińska ◽  
Wiesław Podyma ◽  
...  

Common valerian (Valeriana officinalis L.) is one of the most important medicinal plants, with a mild sedative, nervine, antispasmodic and relaxant effect. Despite a substantial number of studies on this species, the genetic diversity and population structure have not yet been analyzed. Here, we use a next-generation sequencing-based Diversity Array Technology sequencing (DArT-seq) technique to analyze Polish gene bank accessions that originated from wild populations and cultivars. The major and, also, the most astounding result of our work is the low level of observed heterozygosity of individual plants from natural populations, despite the fact that the species is widespread in the studied area. Inbreeding in naturally outcrossing species such as valerian decreases reproductive success. The analysis of the population structure showed the potential presence of a metapopulation in the central part of Poland and the formation of a distinct gene pool in the Bieszczady Mountains. The results also indicate the presence of the cultivated gene pool within wild populations in the region where the species is cultivated for the needs of the pharmaceutical industry, and this could lead to structural and genetic imbalances in wild populations.

2019 ◽  
Author(s):  
Maja Boczkowska ◽  
Katarzyna Bączek ◽  
Olga Kosakowska ◽  
Anna Rucińska ◽  
Wiesław Podyma ◽  
...  

Abstract Background: Valeriana officinalis L. is one of the most important medicinal plant with a mild sedative, nervine, antispasmodic and relaxant effect. Despite a substantial number of studies on this species, population genomics has not yet been analyzed. The main aim of this study was: characterization of genetic variation of natural populations of V. officinalis in Poland and comparison of variation of wild populations and the cultivated form using Next Generation Sequencing based DArTseq technique. We also would like to establish foundations for genetic monitoring of the species in the future and to develop genetic fingerprint profile for samples deposited in gene bank and in natural sites in order to assess the degree of their genetic integrity and population structure preservation in the future.Results: The major and also the most astounding result of our work is the low level of observed heterozygosity of individual plants from natural populations despite the fact that the species is widespread in the studied area. Inbreeding, in naturally outcrossing species such as valerian, decreases the reproductive success. The analysis of the population structure indicated the potential presence of metapopulation in a broad area of Poland and the formation of a distinct gene pool in Bieszczady Mountains. The results also indicate the presence of individuals of the cultivated form in natural populations in the region where the species is cultivated for the needs of the pharmaceutical industry and this could lead to structural and genetic imbalance in wild populations.Conclusions: The DArTseq technology can be applied effectively in genetic studies of V. officinalis. The genetic variability of wild populations is in fact significantly lower than assumed. Individuals from the cultivated population are found in the natural environment and their impact on wild populations should be monitored.


Author(s):  
Kotaro Dokan ◽  
Sayu Kawamura ◽  
Kosuke M Teshima

Abstract Single nucleotide polymorphism (SNP) data are widely used in research on natural populations. Although they are useful, SNP genotyping data are known to contain bias, normally referred to as ascertainment bias, because they are conditioned by already confirmed variants. This bias is introduced during the genotyping process, including the selection of populations for novel SNP discovery and the number of individuals involved in the discovery panel and selection of SNP markers. It is widely recognized that ascertainment bias can cause inaccurate inferences in population genetics and several methods to address these bias issues have been proposed. However, especially in natural populations, it is not always possible to apply an ideal ascertainment scheme because natural populations tend to have complex structures and histories. In addition, it was not fully assessed if ascertainment bias has the same effect on different types of population structure. Here we examine the effects of bias produced during the selection of population for SNP discovery and consequent SNP marker selection processes under three demographic models: the island, stepping-stone, and population split models. Results show that site frequency spectra and summary statistics contain biases that depend on the joint effect of population structure and ascertainment schemes. Additionally, population structure inferences are also affected by ascertainment bias. Based on these results, it is recommended to evaluate the validity of the ascertainment strategy prior to the actual typing process because the direction and extent of ascertainment bias vary depending on several factors.


2021 ◽  
Author(s):  
Karin Rengefors ◽  
Raphael Gollnisch ◽  
Ingrid Sassenhagen ◽  
Karolina Härnström Aloisi ◽  
Marie Svensson ◽  
...  

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1282
Author(s):  
Yu Wang ◽  
Zhongyi Jiao ◽  
Jiwei Zheng ◽  
Jie Zhou ◽  
Baosong Wang ◽  
...  

Chosenia arbutifolia (Pall.) A. Skv. is a unique and endangered species belonging to the Salicaceae family. It has great potential for ornamental and industrial use. However, human interference has led to a decrease in and fragmentation of its natural populations in the past two decades. To effectively evaluate, utilize, and conserve available resources, the genetic diversity and population structure of C. arbutifolia were analyzed in this study. A total of 142 individuals from ten provenances were sampled and sequenced. Moderate diversity was detected among these, with a mean expected heterozygosity and Shannon’s Wiener index of 0.3505 and 0.5258, respectively. The inbreeding coefficient was negative, indicating a significant excess of heterozygotes. The fixation index varied from 0.0068 to 0.3063, showing a varied genetic differentiation between populations. Analysis of molecular variance demonstrated that differentiation accounted for 82.23% of the total variation among individuals, while the remaining 17.77% variation was between populations. Furthermore, the results of population structure analysis indicated that the 142 individuals originated from three primitive groups. To provide genetic information and help design conservation and management strategies, landscape genomics analysis was performed by investigating loci associated with environmental variables. Eighteen SNP markers were associated with altitude and annual average temperature, of which five were ascribed with specific functions. In conclusion, the current study furthers the understanding of C. arbutifolia genetic architecture and provides insights for germplasm protection.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10485
Author(s):  
Zhixin Wang ◽  
Yalin Sun ◽  
Xinfang Huang ◽  
Feng Li ◽  
Yuping Liu ◽  
...  

Taro (Colocasia esculenta) is an important root and tuber crop cultivated worldwide. There are two main types of taro that vary in morphology of corm and cormel, ‘dasheen’ and ‘eddoe’. The eddoe type (Colocasia esculenta var. antiquorium) is predominantly distributed throughout China. Characterizing the genetic diversity present in the germplasm bank of taro is fundamental to better manage, conserve and utilize the genetic resources of this species. In this study, the genetic diversity of 234 taro accessions from 16 provinces of China was assessed using 132,869 single nucleotide polymorphism (SNP) markers identified by specific length amplified fragment-sequencing (SLAF-seq). Population structure and principal component analysis permitted the accessions to be categorized into eight groups. The genetic diversity and population differentiation of the eight groups were evaluated using the characterized SNPs. Analysis of molecular variance showed that the variation among eight inferred groups was higher than that within groups, while a relatively small variance was found among the two morphological types and 16 collection regions. Further, a core germplasm set comprising 41 taro accessions that maintained the genetic diversity of the entire collection was developed based on the genotype. This research is expected to be valuable for genetic characterization, germplasm conservation, and breeding of taro.


2019 ◽  
Vol 67 (1) ◽  
pp. 191-208 ◽  
Author(s):  
Fiacre Zavinon ◽  
Hubert Adoukonou-Sagbadja ◽  
Jens Keilwagen ◽  
Heike Lehnert ◽  
Frank Ordon ◽  
...  

2021 ◽  
Author(s):  
Tao Zhang ◽  
Xue Li ◽  
Shuilian He

Abstract Magnolia odoratissima is a highly threatened species with small populations and scattered distribution due to habitat fragmentation and human activity. The species is recognized as a Plant Species with Extremely Small Populations (PSESP) and is endemic to China. In the current study, the population structure and levels of genetic diversity of M. odoratissima in the five remaining natural populations and three cultivated populations were evaluated using single nucleotide polymorphisms (SNPs) derived from Specific-Locus Amplified Fragment Sequencing (SLAF-seq). A total of 180,650 SNP loci were found in seventy M. odoratissima individuals. The genome-wide Nei’s and Shannon’s nucleotide diversity indexes of the total M. odoratissima population were 0.3035 and 0.4695, respectively. The observed heterozygosity (Ho) and expected heterozygosity (He) were 0.1122 and 0.3011. Our results suggest that M. odoratissima has relatively high genetic diversity at the genomic level. FST and AMOVA indicated that high genetic differentiation existed among populations. A phylogenetic neighbor-joining tree, Bayesian model–based clustering and principal components analysis (PCA) all divided the studied M. odoratissima individuals into three distinct clusters. The Treemix analysis showed that there was low gene flow among the natural populations and a certain gene flow from the wild populations to the cultivated population (LS to KIB, and GN to JD). In addition, a total of 36 unique SNPs were detected as being significantly associated with environmental parameters (altitude, temperature and precipitation). These candidate SNPs were found to be involved in multiple pathways including several molecular functions and biological process, suggesting they may play key roles in environmental adaptation. Our results suggested that three distinct evolutionary significant units (ESUs) should be set up to conserve this critically endangered species.


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