Genetic Pattern and Diversity of Barbatia virescens: A RAD-Seq Analysis of Five Geographically Distributed Populations.

Microsatellite analysis sheds light on the conservation of Dyckia brevifolia Baker

Dyckia brevifolia is a riparian bromeliad endemic to southern Brazil. Despite the endangered status of this species, no genomic resources are available to aid conservation initiatives. This study describes the investigation of the genetic diversity and structure of D. brevifolia populations using newly neutral, species-specific nuclear microsatellite markers developed through genome skimming. Genotyping thirty individuals from three populations with nine generated microsatellite markers revealed low levels of allelic and genetic diversity (A = 2.56 and He = 0.39, Ho = 0.19) and high fixation index (f = 0.46), indicating significant inbreeding levels. Principal coordinates analysis suggested the occurrence of gene flow directed by river current, favoring downstream populations, which evidences hydrochorous dispersal of propagules. These primary data using molecular markers provide the basis for designing conservation strategies to ensure the maintenance of gene flow and genetic variability in the fragmented populations of D. brevifolia.

Unravelling the genetic diversity and population structure of Sitophilus oryzae L. in North India using mitochondrial COI sequences

Aim: Sitophilus oryzae (Linnaeus) (Coleoptera: Curculionidae) is a notorious pest inflicting substantial economic damage to stored grains worldwide. Population genetic studies offer valuable insights into insects' evolutionary and adaptive strategies and demonstrate how environmental factors influence genetic diversity and gene flow among populations.Therefore, the present study was undertaken to study the genetic diversity of S. oryzae populations from different geographical regions of North India. Methodology: In this study, a total of 150 samples of S. oryzae were collected from 15 different locations, representing diverse agro-climatic zones of India. The samples were then identified by utilizing taxonomic keys. Thereafter, the specimens were subjected to PCR amplification of mitochondrial cytochrome c oxidase I (COI) gene to study their genetic variation and population structure. Results: The results revealed low values of haplotype diversity (0.178) and nucleotide diversity (0.00032). Significant negative values of neutrality tests suggested a recent demographic expansion of the population. Mantel's test revealed a weak correlation between genetic differentiation and geographical distance. Haplotype network analysis revealed a single major clade, representing the major population assumed to be the ancestral population. Moreover, low-frequency haplotypes with one or two populations suggested ongoing population divergence, possibly influenced by phosphine resistance mechanisms. The phylogenetic tree supported the genetic homogeneity of the population since there was no clustering of the population based on geographical area. Interpretation: Based on the COI markers, it can be concluded that North Indian populations of S. oryzae exhibit low genetic diversity, which has implications for pest management strategies primarily involving the use of fumigants. Key words: COI, Genetic homogeneity, Gene flow, Phylogeny, Sitophilus oryzae

Genetic Diversity of the 4th-Cycle Breeding Population of Cunninghamia lanceolata (Lamb.) Hook. Using SSR Markers

: Cunninghamia lanceolata (Lamb.) Hook., a fast-growing timber species endemic to China, has been constrained in genetic improvement and marker-assisted breeding programs by the paucity of molecular-level genetic diversity information. In this study, 22 pairs of highly polymorphic SSR molecular markers were designed and developed based on transcriptome sequencing and public data, and subsequently employed for genetic diversity analysis of 258 germplasm accessions. These primers amplified 235 alleles across all accessions, averaging 10.682 alleles per marker. The mean observed heterozygosity (Ho) and expected heterozygosity (He) were 0.543 and 0.668, respectively, and the polymorphic information content (PIC) values ranged from 0.237 to 0.947, with a mean of 0.627, indicating substantial genetic diversity within the tested germplasm panel. Bayesian population structure analysis resolved the 258 accessions into 11 distinct genetic groups, with group 11 comprising 155 individuals and exhibiting the most complex provenance composition—a pattern independently corroborated by phylogenetic reconstruction and Principal Coordinate Analysis (PCoA). Among 11% of the genetic variation originated between populations and 89% from within populations. Pairwise estimates of Nei’s genetic distance and pairwise FST indicated frequent historical gene flow and close genetic relatedness among most groups. These findings provide a valuable empirical reference for germplasm evaluation and marker-assisted breeding in C. lanceolata .

Population Genetic Structure and Reduced Diversity in Upstream Populations of the Endangered Nakdong Nose Loach ( Koreocobitis naktongensis ) Revealed by Novel Microsatellite Markers

We developed and validated seven polymorphic microsatellite loci for the endangered Nakdong nose loach ( Koreocobitis naktongensis ) and used them to assess genetic diversity and population structure across the Nakdong River basin in the Republic of Korea. The loci showed reliable Mendelian segregation within five full‐sib families, and no evidence of null alleles was detected. Genotyping of 126 individuals from eight sites revealed substantial overall genetic diversity (mean A R  = 4.46; H E  = 0.759) although diversity was lower in several populations upstream of dams (WS: A R  = 3.70, H E  = 0.681; DCR: 4.17, 0.709; GHR: 3.66, 0.655). Genetic differentiation was greater in comparisons involving some upstream populations, and a significant isolation‐by‐distance pattern indicated that river distance contributed to genetic structuring across the basin. Across analyses, WS and DCR + GHR were populations upstream of dams that were most consistently differentiated from the others. These results provide evidence of spatial genetic structure within the basin and highlight WS and DCR + GHR as priorities for future monitoring and conservation planning.

Whole-genome resequencing of wild Hyrcanian and cultivated figs (Ficus carica L.) for genetic diversity and population structure

Exploratory SSR-Based Assessment of Genetic Diversity and Differentiation Among Four Wild Almond Populations in Kazakhstan

Wild almond relatives are valuable reservoirs of allelic variation for crop improvement and conservation, yet Kazakhstan’s wild-almond genetic resources remain poorly characterised. We conducted an exploratory SSR assessment of 80 putative individuals from four taxon-locality groups (20 per group), each representing one sampled population: Prunus ledebouriana, P. tenella, P. petunnikowii, and P. spinosissima. Of 22 nuclear simple sequence repeat loci screened for cross-taxon transferability, 15 generated reproducible profiles and were retained; their even genome-wide distribution was not verified. Across the full dataset, the mean number of alleles was 3.55, the effective number of alleles was 2.62, expected heterozygosity (He) was 0.544, and 95.0% of loci were polymorphic. Missing genotypes ranged from 0.0% to 34.7% among groups, and six loci had at least 20% missing data. AMOVA attributed 76.5% of variation to within-group differences and 23.5% to among-group differences (PhiPT = 0.235, p = 0.001). PCoA, unbiased Nei distances, UPGMA, and descriptive Bayesian clustering separated the four sampled groups. A nine-locus sensitivity analysis that excluded the six high-missing loci retained P. spinosissima as the group with the highest mean He (0.699), whereas P. petunnikowii increased from 0.471 to 0.609. Thus, the low full-panel estimate for P. petunnikowii was not robust to missing data. Because taxon identity was fully confounded with locality and the marker panel was limited, the results are interpreted as a regional marker-transferability and methodological baseline rather than as species-wide or genome-wide inference.