Project description:Eucalyptus urophylla is a commercially important wood crop plantation species due to its rapid growth, biomass yield, and use as bioenergy feedstock. We characterized the genetic diversity and population structure of 332 E. urophylla individuals from 19 geographically defined E. urophylla populations with a reliability of 14,468 single nucleotide polymorphisms (SNPs). We compared the patterns of genetic variation among these 19 populations. High levels of genetic diversity were observed throughout the 19 E. urophylla populations based on genome-wide SNP data (HE=0.2677 to 0.3487). Analysis with STRUCTURE software, Principal component analysis (PCA) and a neighbor-joining (NJ) tree indicated that E. urophylla populations could be divided into three groups, and moderate and weak population structure was observed with pairwise genetic differentiation (FST) values ranging from −0.09 to 0.074. The low genetic diversity and shallow genetic differentiation found within the 19 populations may be a consequence of their pollination system and seed dispersal mechanism. In addition, 55 core germplasms of E. urophylla were constructed according to the genetic marker data. The genome-wide SNPs we identified will provide a valuable resource for further genetic improvement and effective use of the germplasm resources.
2023-01-31 | GSE145072 | GEO
Project description:SLAF-seq based genetic diversity and structure of geodorum eulophioides, an endangered terrestrial orchid species with extremely small populations in China.
Project description:Free-breeding dogs have occupied the Galápagos islands at least since the 1830s, however, it was not until the 1900s that dog populations grew substantially, endangering wildlife and spreading disease. In 1981, authorities sanctioned the culling of free-roaming dogs. Yet there are currently large free-roaming dog populations of unknown ancestry on the islands of Isabela and Santa Cruz, whose ancestry has never been assessed on a genome-wide scale. Thus, we performed a complete genomic analysis of the current Galápagos dog population as well as historical Galápagos dogs sampled between 1969 and 2003, testing for population structure, admixture, and shared ancestry. Our dataset included samples from 187 modern and six historical Galápagos dogs, together with whole genome sequence from over 2,000 modern purebred and village dogs. Our results indicate that modern Galápagos dogs are recently admixed with purebred dogs but show no evidence of a population bottleneck related to the culling. Additionally, IBD analyses reveal evidence of shared shepherd-dog ancestry in the historical Galápagos dogs. Overall, our results demonstrate that the 1980s culling of dogs was ineffective in controlling population size and did little to reduce genetic diversity, instead producing a stable and expanding population with genomic signatures of historical dogs remaining today. The insights from this study can be used to improve population control strategies for the Galápagos Islands and other endangered endemic communities worldwide.
2024-10-01 | GSE276576 | GEO
Project description:Root associated fungal diversity of Calanthe orchid species in Korea
Project description:Survey of post pollination events in a sexually deceptive orchid (Ophrys fusca): a transcriptional approach Pollination through deception is a widespread phenomenon in angiosperm, and is extremely common in Orchidaceae family. One of the most striking pollination mechanism in orchids is known as sexual deception, in which flowers lure pollinators by foraging chemical (sex pheromones), visual (e.g. labellum colour and/or shape) and tactile (e.g. labellum pilosity) cues of the female insect pollinator. Ophrys has been used as a model genus to study sexual deception mechanism, mainly regarding chemical analysis in plant-insect association. Study was focused on Ophrys fusca, a species widely distributed in Mediterranean Basin. The main objective rely on Ophrys fusca gene expression study after pollination, through a transcriptional approach using cDNA microarrays. In order to evaluate pollination enhanced events, two different time points were selected: 2 days and 4 days after pollination. Ophrys fusca plants were sampled from a Portuguese natural occurring population. Plants were covered with a white and inert net, built specially for preventing pollinator’s visits in both pollinated and unpollinated flowers. Cross- pollination was performed manually with a sterile plastic stick. Five biological replicates (5 plants in each replicate) from each condition (pollinated and unpollinated) were collected in each time-point Flowers that demonstrate strict pollination regulation, as orchids, provide an excellent model system to unravel pollination- elicited mechanisms (i.e. petal senescence, pigmentation changes, ovary growth). Therefore, this study aims to contribute to the overall knowledge on orchid pollination biology, which is still lacking. 2 time points: 2 days and 4 days after pollination.Two-samples accessed: control (nonpollinated labella) and test (pollinated labella). 5 Biological replicates and 2 technical replicates (repeats of labelling and hybridization using randomly chosen biological replicates) in each time point were made.