High Level Of Genetic Diversity Research Articles

Genetic Analysis of the Brown Bear Sub-Population in the Pindos Mountain, Central Greece: Insights into Population Status and Conservation

Habitat fragmentation poses a significant threat to the existence and reproduction of large carnivores, such as brown bears, as it affects the genetic connectivity of populations and, consequently, their long-term viability. Understanding the genetic makeup and dispersal patterns in areas where brown bears live is crucial for developing effective conservation plans and promoting human-brown bear coexistence. In this study, 214 hair samples were collected non-invasively from brown bears and were genetically analyzed using fifteen specific microsatellite loci to shed light on the genetic status and demography of a sub-population residing in Central Greece (Trikala-Meteora area). The broader Central and South Pindos regions have not been studied for over a decade; however, high levels of genetic diversity, a lack of heterozygosity deficiency, and no signs of inbreeding, along with an estimated effective population size (Ne = 99), confirm the good conservation status of this sub-population. Moreover, the existence of a natural and apparently functional corridor in Central Pindos was demonstrated by bear movements between the western and eastern parts of the project area, enhancing the sustainability of the population. These findings will contribute to future efforts to conserve natural corridors that enable functional connectivity among large areas of brown bear territories in Greece.

Genetic Diversity Analysis and Identification of Candidate Genes for Growth Traits in Chengkou Mountain Chicken.

Growth traits constitute critical factors in the breeding program of broiler chickens. The Chengkou mountain chicken A-lineage (CMC-A) represents a breed specifically bred for meat production. To further explore the growth performance of the CMC-A population, this study conducted whole-genome sequencing on 464 CMC-A roosters to systematically evaluate their genetic diversity. Additionally, runs of homozygosity (ROH) islands and genome-wide association studies (GWASs) were employed to identify the loci and functional genes influencing the growth traits in Chengkou mountain chickens. The results revealed a high level of genetic diversity and low levels of inbreeding in Chengkou mountain chickens. Several genes associated with stress resistance, muscle growth, and fat deposition were pinpointed through ROH island identification. Moreover, 52 SNP loci were detected, along with 71 candidate genes. These findings enhance our understanding of the genetic architecture underlying the growth traits in Chengkou mountain chickens and provide a theoretical foundation for subsequent breeding endeavors.

Evolutionary Genomics Provides Insights Into Endangerment and Conservation of a Wild Apple Tree Species, Malus sieversii.

Understanding the evolutionary history of a species is essential for effective conservation management. Malus sieversii, a relict broad-leaf forest tree found in arid Central Asian mountains, has a narrow and fragmented distribution and is classified as an endangered species in China. This species is considered one of the ancestors of the domesticated apple trees. In the present study, we sampled five populations of M. sieversii and its wide-ranging congener M. baccata from China. Through deep whole-genome resequencing, we analyzed the population's genetic diversity, genetic structure, demographic history, fixation of deleterious mutations, and genomic divergence. Our results revealed that M. baccata exhibits a higher level of genetic diversity than M. sieversii. The effective population size of M. sieversii decreased, whereas that of M. baccata recovered after the bottleneck effect. In M. sieversii, the genetic structure of the Yili region was distinct from that of the Tacheng region. Populations at the rear edge of the Tacheng region showed a stronger fixation of deleterious mutations than those in the Yili region. Genomic divergence indicated that the positively selected genes were associated with physiological processes within the genomic islands between the Yili and Tacheng regions. Based on these findings, we recommend the establishment of two separate conservation units for the Yili and Tacheng lineages to preserve their genetic resources. Given the limited distribution range and high fixation rate of deleterious mutations, urgent protective measures are recommended for the Tacheng lineage.

Genetic Variability and Association Studies on Yield and Yield Attributing Traits in Blackgram (Vigna mungo L. Hepper)

Aims: Low and static productivity (450–800 kg/ha) is one of the main obstacles in blackgram (Vigna mungo L. Hepper) crop. The low productivity is due to inadequate seed systems, a lack of access to genetic and genomic resources, and a lack of active breeding initiatives. Hence the present study was carried out to assess the variability and association among yield contributing traits for blackgram improvement programmes. Place and Duration of Study: The field study was carried out during 2019-2020 in V.O. Chidambaranar Agricultural College and Research Institute, Killikulam, Tamil Nadu Agricultural University at Department of Genetics and Plant Breeding. Study Design and Methodology: A total of 60 F4 progenies developed from the cross IC 436656 x KKB14045 in blackgram for the assessment of per se performance, genetic variability and association studies. Results: Based on the production of a single plant, seventeen offspring were determined to be promising. The traits viz., number of clusters per plant, number of pods per plant, and single plant yield showed high PCV and GCV, which indicated that there was a high level of genetic variability in the population. The variables of plant height, number of clusters / plant, number of pods/plant, and single plant yield showed significant heritability and high genetic advancement, indicating additive gene action. Single plant yield was positively and significantly correlated with the traits viz., plant height, number of clusters / plant, number of pods / plant, and number of seeds / pod. Therefore, choosing these characteristics is crucial to creating high yielding blackgram cultivars.

Principal Component Analysis for Assessing Genetic Variation and Key Traits in Bottle Gourd [Lagenaria siceraria (Molina) Standl.] Genotypes

The present investigation was carried out at the Experimental field of Urban Technological Park Habbak, Srinagar, Jammu and Kashmir during kharif-2022. The experiment was laid out in Augmented Randomized Block Design with three blocks and plant spacing of 2×1 m for seventy-seven genotypes including two checks, Pusa Naveen and Pusa Santushti. Observations were recorded for growth and yield traits, seed traits and quality parameters. Principal Component Analysis (PCA) was carried out based on twenty-one quantitative and four quality characters in bottle gourd. Six out of the ten principal components, with eigen values above 1.0, explained 69.56% of the total variation. The first PC accounts for the maximum variability in the data i.e., 20.08%. The remaining variability of 17.90%, 10.05%, 8.23%, 6.82% and 6.48% was consolidated in PC2, PC3, PC4, PC5 and PC6 respectively. This population panel can be used for trait improvement in breeding programs for the traits contributing to major variation because the results of the principal component analysis used in the study have shown the high level of genetic variation and the traits contributing to the variation.

Assessing population genetic structure and diversity and their driving factors in Phoebe zhennan populations

BackgroundPhoebe zhennan, commonly known as “golden-thread nanmu,” is one of the most valuable and protected tree species in China. An accurate understanding of the population genetic structure and its environmental factors is of significance for the protection and selection of new P. zhennan varieties.ResultsSixteen nSSR and six cpSSR markers were used to determine the genetic diversity and population structure of P. zhennan and the effect of environmental factors on the genetic structure. The nSSR markers identified a total of 451 number of alleles (Na), while cpSSR markers detected 20 Na. A relative high level of genetic diversity was observed in the P. zhennan population evidenced by high Shannon’s information index (I) of 0.671 and 2.294 based on cpSSR and nSSR datasets. The low value of fixation index (F) observed from the nSSR dataset indicated low breeding within the population. The genetic differentiation was mainly detected within populations (only 28% and 13% of the variance being between populations according to the nSSR and cpSSR datasets). Among them, the HNSZX (H = 0.469) and SCSZZ (I = 1.943) populations exhibited the highest level of genetic diversity, while the HNXXT (H = 0.041) and SCLJS (I = 0.943) populations exhibited the lowest level of genetic diversity. The average genetic differentiation coefficient (Fst) and gene flow (Nm) were 0.022–0.128 and 1.698–11.373, respectively, which indicated a moderate level of genetic differentiation and a high level of gene flow. STRUCTURE, neighbor-joining clustering, and principal coordinate analysis divided 543 individuals into two or three categories based on the nSSR or cpSSR datasets. Four temperature, three precipitation, five chemical, five physical, and one soil texture variable showed significant effects on the genetic structure and distribution of P. zhennan populations. Compared to nSSR, the genetic differentiation among populations based on cpSSR datasets conformed to the geographic isolation model, suggesting that geographic and genetic distances should be considered for further genetic conservation and breeding utilization. The importance of in situ conservation units, such as populations with a high level of genetic diversity, more private alleles, and haplotypes (e.g., population SCGTS, SCYFS, and YNYJX), should be emphasized. Additionally, breeding, along with artificially assisted population regeneration and restoration, should also be carefully planned, taking into account climate and soil properties at the same time.ConclusionsIn conclusion, this study provided genetic background information for the genetic conservation, management, and utilization of P. zhennan.

Microsatellite based molecular characterization of Nattukuttai- a unique short statured Bos indicus cattle population of southern India.

Molecular characterization was conducted to characterise 'Nattukuttai', a native cattle population of the north-eastern agro-climatic zone of Tamil Nadu (India), using thirty microsatellite markers. The analyses revealed a high level of genetic diversity, with a total of 294 alleles observed across all the loci, averaging 9.8 alleles per locus. The allele sizes ranged from 83bp to 302bp, with frequencies ranging from 0.010 to 0.875. The microsatellite markers demonstrated high polymorphism, as indicated by an average polymorphic information content (PIC) of 0.763. Deviation from Hardy-Weinberg equilibrium was observed in a significant number of loci, indicating possible genetic influences such as selection or population structure. Bottleneck analysis suggested that the Nattukuttai population did not undergo any recent significant population contraction. Comparative analyses with three other cattle populations (Kangayam, Malai Madu, and Malnad Gidda) revealed varying genetic distances. Nattukuttai showed a distinct genetic profile, diverging from a common source that also gave rise to the Kangayam and Malai Madu clusters. Multivariate statistical analyses and phylogenetic reconstruction supported the genetic differentiation of Nattukuttai from the other populations, while Malai Madu and Kangayam were found to be genetically closer to each other. Overall, these findings provide insights into the genetic structure and relationships of the Nattukuttai cattle population, highlighting its distinct genetic identity and potential conservation significance.

Genetic Diversity and Population Structure Analysis of Pinus elliottii Germplasm Resources in Jiangxi Province.

This study aimed to compare and assess the genetic diversity and trends among the introduced family provenance, first-cycle superior trees breeding provenance, and improved-generation superior trees breeding provenance of Pinus elliottii using EST-SSR markers. The goal was to provide a foundation for advanced genetic improvement and sustainable utilization of P. elliottii in Jiangxi Province. A total of 417 individuals were analyzed for their genetic diversity and population structure using 19 pairs of SSR markers. The analysis identified 103 alleles across all the samples, with an average of 5.421 alleles per locus. Compared to other coniferous species, P. elliottii exhibited a moderate to high level of genetic diversity (I = 0.862, He = 0.457). Analysis of the molecular variance (AMOVA) revealed that 97.90% of the genetic variation occurred within provenances, consistent with a low genetic differentiation coefficient (Fst = 0.016 < 0.05) and high gene flow (Nm = 15.715) among provenances. In addition, analysis using STRUCTURE v. 2.3.4 software divided the 417 germplasm samples into two distinct groups, corroborating the results of the principal coordinates analysis (PCoA) and the unweighted pair group method with arithmetic (UPGMA) clustering analysis. Overall, the germplasm resources of P. elliottii exhibited rich genetic diversity, with the majority of the genetic variation occurring within provenances. For the genetic improvement of high-resin-yielding slash pines, breeding programs should prioritize populations with high genetic diversity while carefully selecting superior individuals from within those populations. These findings provide a solid foundation for breeding high-resin-yielding varieties and for future research on the sustainable utilization of these valuable resources.

Haplotype diversity and phylogeny within Alternaria alternata and A. arborescens species complexes from tomatoes

Tomato (Solanum lycopersicum L.) is an economically important vegetable susceptible to various fungal diseases, including leaf spot caused by Alternaria spp. from the section Alternaria. In our study, a total of 72 tomato-associated Alternaria spp. strains from Latvia, Lithuania, Estonia, and Algeria were analysed by integrating morphological data, pathogenicity assay, multi-locus phylogeny, and haplotype assignment. Recovered Alternaria spp. strains were characterized by considerable variation in phenotypic diversity, non-pathogenicity to their host of origin and absence of the AAL-toxin biosynthesis gene (ALT1). Multi-locus phylogeny of the RNA polymerase II second largest subunit (rpb2), putative F-box-domain-containing protein (ASA-10), and putative histone-like transcription factor (ASA-19) confirmed the occurrence of both A. alternata and A. arborescens species complexes along with A. longipes and A. postmessia on symptomatic tomatoes. The discordant tree topology among single-gene phylogenies suggested the occurrence of potential recombination between phylogenetic lineages in the section Alternaria, resulting in putative alternata-arborescens and alternata-longipes hybrids. DNA polymorphism analysis of the rpb2, ASA-10, and ASA-19 loci revealed a high level of genetic diversity in the section Alternaria, and the number of single nucleotide polymorphisms (SNPs) and haplotypes varied among loci and lineages studied. A total of 16 and 6 multi-locus haplotypes were assigned in alternata and arborescens lineages, respectively. Global genetic diversity analysis of A. alternata and A. arborescens strains at the rpb2 locus confirmed that major haplotypes described from tomatoes were shared among other hosts of origin.

Utilizing SSR-based core collection development to improve conservation and utilization of Corylus L. genetic resources.

Hazelnuts are traditional woody oilseed plants. Corylus L. resources are rich in variety and widely distributed in China. However, the identification of germplasm varieties and the selection of superior varieties remain quite limited. This study aimed to analyze the genetic diversity of 331 Corylus L. germplasms using 16 simple sequence repeat (SSR) markers. Based on this, 11 pairs of core primers were selected, a fingerprint database of germplasm resources was constructed, and a primary core collection was screened. The results indicated that these tested Corylus L. germplasms exhibited a high level of genetic diversity, with an average number of alleles (Na) per locus of 14.5 and a polymorphic information content of 0.777. The phylogenetic relationships among various hazelnut cultivars were characterized by complexity, and they were delineated into four distinct groups facilitated by genetic distance analyses. An SSR fingerprint database for 331 Corylus L. germplasms was successfully constructed using the 11 obtained core SSR markers to increase the discrimination efficiency. Ultimately, 127 primary core accessions of Corylus L. were selected. The retention rate for the observed Na and MAF (the minor allele frequency) in the primary core germplasm constructed based on a sampling proportion of 38.36% was 100% and 94.7%, respectively. Shannon's information index (I) was highly consistent between the core and original germplasms, indicating that the core germplasm could fully represent the genetic diversity of the original germplasm. Additionally, the principal coordinate analysis of the selected primary core germplasm was essentially consistent with that of the entire original germplasm, further supporting the broad representativeness of the core germplasm. This study provided a basis for precisely identifying and efficiently utilizing Corylus L. accession.

Multiple Maternal Lineages of &lt;i&gt;Strauchbufo raddei&lt;/i&gt; (Strauch, 1876) in Mongolia Revealed by Mitochondrial DNA

The Mongolian toad Strauchbufo raddei (Strauch, 1876) is one of widely distributed and dominated amphibian species in eastern Asian, including Mongolia. In this study, we amplified and sequenced a total of 50 samples of S. raddei, from three main regions in its Mongolian distribution range namely, Northern, Eastern, and Gobi regions. Our phylogenetic trees (Bayesian inference; BI and time-calibrated) and network analysis clearly support presence of multiple maternal mitochondrial DNA lineages for S. raddei in Mongolia. As expected, samples from these three regions were clustered separately in BI tree (Bayesian posterior probability (BPP 0.52). In addition, the population specific haplotypes, estimated genetic distances (e.g. uncorrelated p distance; ranged from 1% to 25%) and hierarchical AMOVA suggested relatively strong population genetic structure of S. raddei across Mongolia. Time-calibrated tree and ancestral range analysis showed that the first colonization of S. raddei may have occurred in Northern part of Mongolia approximately 9.63 mya, then dispersed over other parts of the country. Estimated approximate time for crossing event of S. raddei over dry steppe and semi-desert regions in Mongolia was 5.02 – 2.50 mya. Finally, high level of genetic diversity (overall; haplotype diversity, Hd = 0.93; nucleotide diversity, π = 0.011) of S. raddei were observed in Mongolia. Importantly, through this study, we contributed to closing sampling gaps in distribution range of S. raddei in Eastern Asia, which is key to better understanding species history, as well as describing cryptic lineages.

Temporal and inter-specific population genetics analyses of Sebastiscus marmoratus and S. tertius provide novel implications for fishery management

ABSTRACT Understanding population genetic diversity and evolutionary dynamics of marine fish species can provide theoretical bases for fishery management and germplasm conservation, especially facing a changing environment. The rockfish species in genus Sebastiscus are economically important species for farming and sport fisheries in China, Japan and Korea. In this study, inter-annual and inter-specific comparisons on genetic diversity, population differentiation and historical demography of S. marmoratus and S. tertius collected from coastal waters of Zhangzhou, China were conducted using mitochondrial control region sequences. High levels of genetic diversity were observed in both species, indicating high adaptive potential to environmental changes. Demographic analyses detected recent population expansion in population S. tertius (Ste-2020) and population S. marmoratus collected in 2020 (Sma-2020), yet failed in population collected in 2016 (Sma-2016). Moreover, in population Sma-2020, novel haplotypes were detected and grouped into a separate sub-branch, revealed by neighbour-joining topology. Detected recent population expansion and novel haplotypes might be considered as a response to environmental changes. Besides, results of genetic differentiation analysis suggested high intra-specific genetic variation in both species. These genetic data and information will provide novel implications for strengthening the management of S. marmoratus and S. tertius fisheries in climate change scenarios.

Monitoring spatiotemporal patterns in the genetic diversity of a European butterfly species

Abstract The importance of genetic diversity has been recognised by the Convention on Biological Diversity but attempts at monitoring or improving the genetic diversity of populations have been minimal. Here, we investigate changes over time in the genetic diversity of a wild insect species, Maniola jurtina (Lepidoptera: Nymphalidae) and present a large‐scale investigation into contemporary spatial genetic diversity. Using microsatellite markers, we calculate multiple measures of genetic diversity and divergence for M. jurtina populations over 8 years in the UK and compare these findings with long‐term abundance trends. We also conduct a large‐scale spatial analysis into the genetic diversity and population structuring of M. jurtina across Europe. All UK populations sampled have high levels of gene flow and genetic diversity, with genetic diversity stable over time. Across Europe, we find some population structuring between populations in the UK and the European mainland, suggesting restricted geneflow between the two regions. The monitoring of a wild species' genetic diversity is an achievable aim, and one that could be carried out for many species, particularly Lepidoptera. Future approaches may aim to develop higher resolution genetic markers and cover a wider range of species. The use of abundance data offers additional insight, and we find that concurrent, dedicated genetic monitoring can provide effective tracking of biodiversity trends.

Population Genomics of Adaptive Radiations: Exceptionally High Levels of Genetic Diversity and Recombination in an Endemic Spider From the Canary Islands.

The spider genus Dysdera has undergone a remarkable diversification in the oceanic archipelago of the Canary Islands, with ~60 endemic species having originated during the 20 million years since the origin of the archipelago. This evolutionary radiation has been accompanied by substantial dietary shifts, often characterised by phenotypic modifications encompassing morphological, metabolic and behavioural changes. Hence, these endemic spiders represent an excellent model for understanding the evolutionary drivers and to pinpoint the genomic determinants underlying adaptive radiations. Recently, we achieved the first chromosome-level genome assembly of one of the endemic species, D. silvatica, providing a high-quality reference sequence for evolutionary genomics studies. Here, we conducted a low coverage-based resequencing study of a natural population of D. silvatica from La Gomera island. Taking advantage of the new high-quality genome, we characterised genome-wide levels of nucleotide polymorphism, divergence and linkage disequilibrium, and inferred the demographic history of this population. We also performed comprehensive genome-wide scans for recent positive selection. Our findings uncovered exceptionally high levels of nucleotide diversity and recombination in this geographically restricted endemic species, indicative of large historical effective population sizes. We also identified several candidate genomic regions that are potentially under positive selection, highlighting relevant biological processes, such as vision and nitrogen extraction as potential adaptation targets. These processes may ultimately drive species diversification in this genus. This pioneering study of spiders that are endemic to an oceanic archipelago lays the groundwork for broader population genomics analyses aimed at understanding the genetic mechanisms driving adaptive radiation in island ecosystems.

Genetic structure of cattle of the siberian branch by microsatellite loci

Molecular-genetic methods are essential tools for the utilization and conservation of animal genetic resources. These methods facilitate more efficient management and control of breeding programs within livestock production systems. For studying the genetic diversity of a population, the use of STR markers is relevant due to the high variability of repeats. This study presents a genetic characterization of a Holstein and Black Pied cattle population (n = 10233) in Western Siberia using 12 microsatellite loci (BM1818, BM1824, BM2113, ETH10, ETH225, ETH3, INRA023, SPS115, TGLA126, TGLA122, TGLA227, TGLA53). A total of 145 alleles were identified across all loci, with frequencies ranging from 0.00005 to 0.68961. The highest level of genetic diversity was observed at the TGLA122 locus (25 alleles) with an average number of effective alleles (Ne) of 4.5. The least polymorphic locus was BM1824 (7 alleles) with an average Ne of 3.27. The average observed (Ho) and expected (He) heterozygosity across all loci was 0.6. The highest variability was observed at the TGLA53 locus, with a Wright’s fixation index (Fis) of 0.161, indicating a heterozygote deficiency. A similar deficiency was observed at the BM1818 locus. All other loci exhibited a positive Fis, with the highest value observed at the ETH3 locus (-0.074), indicating an excess of heterozygotes. The average Fis across all loci was -0.02, suggesting a sufficient level of heterozygosity within the studied population. These findings provide valuable information for population studies and practical breeding programs aiming to manage genetic diversity and improve selection efficiency in this cattle population.

Genetic Diversity and Population Structure of Endangered Orchid Cypripedium flavum in Fragmented Habitat Using Fluorescent AFLP Markers

Genetic diversity is crucial for determining the evolutionary potential of a species and is essential for developing optimal conservation strategies. The impact of habitat fragmentation on the genetic diversity of food-deceptive orchids seems to be unpredictable because of their specialized seed and pollen dispersal mechanisms. The habitat of deceptive Cypripedium flavum was severely fragmented during the past half century. This study investigated the genetic diversity and structure of seven fragmented Cypripedium flavum populations in Shangrila County using AFLP markers. A total of 376 alleles were identified, with a range of 70 to 81 alleles per locus. The species exhibited considerable genetic diversity, as evidenced by an average Nei’s gene diversity (H) of 0.339 and a Shannon’s information index (I) of 0.505, with all loci being polymorphic. Based on Molecular Variance (AMOVA), 8.75% of the genetic differentiation was found among populations, while the remaining 91.25% of genetic variation occurred within populations. Population structure analysis revealed that the C. flavum germplasm can be categorized into five distinct groups, among which there was significant gene flow. Despite habitat fragmentation, C. flavum still retained a high level of genetic diversity, and the substantial gene flow (5.0826) is a key factor in maintaining the genetic diversity. These findings offer valuable insights for the conservation and potential use of C. flavum genetic resources.

New simple sequence repeat markers reveal undetected diversity in Spanish and Californian Diplodia sapinea populations

Diplodia sapinea is the causal agent of Diplodia shoot blight, an emerging disease affecting pine forests worldwide. The range expansion of this pathogen in northern Europe has been suggested to be partially facilitated by recent warmer conditions. Although D. sapinea has been studied extensively, critical aspects of its infection biology and population structure remain unexplored. In this study, we developed nine simple sequence repeat (SSR) markers mined from D. sapinea genomes to assess the genetic diversity at higher resolution. Isolates from northern Spain, an area formerly regarded as having low genetic diversity and samples from a Californian population that was formerly regarded as clonal, were analysed in the study. In Spain, the nine SSR markers identified 56 genotypes in 285 samples. Isolates from symptomatic shoots, cones and asymptomatic tissues collected from different stands, suggested admixture between local populations. The same genotype tended to dominate within a single cone, and the same genotypes were usually found in both symptomatic and asymptomatic shoot tissues. The nine new SSR markers developed in this study revealed a high level of genetic diversity in both the northern Spanish and northern Californian populations than previously anticipated. Analyses using these nine SSR markers should contribute to a better understanding of the epidemiology, evolution and origin of D. sapinea, a pathogen that is gaining prominence in many parts of the world.

Genetická charakterizace tisu červeného (Taxus baccata L.) v širší oblasti Podyjí/Thayatal a na Svitavsku s vazbou na ochranářský management

The aim of the work is to determine the genetic diversity, genetic differentiation and genetic structure of subpopulations of the specially protected common yew in the area of South Moravian Podyjí (Czech Republic), Thayatal (Austria) and in the Svitavy region (Czech Republic) using DNA analyses (nSSR-nuclear Simple Sequence Repeats). The subjects of the analyses were yews of 1) natural occurrences in the territory of the Podyjí National Park (NP), 2) cultural origin in the Podyjí NP, 3) natural occurrences in the Thayatal NP (Austria), 4) natural occurrences outside the Podyjí NP, and 5) cultural origin in the Podyjí region outside the NP. For the comparison and better interpretation of results there also were analysed geographically more distant subpopulations, 6) natural occurrences in the Hřebečský ridge (NW Moravia), 7) cultural yew occurrences in the Svitavy region (NE Bohemia &amp; NW Moravia), 8) natural occurrences in the Jílovské yews (N Bohemia), and 9) natural occurrences in the Moravian Karst (S Moravia). We observed higher level of genetic diversity (Ho = 0.54; He = 0.77), the FST with ENA correction ranged from 0.007 to 0.123. According to a STRUCTURE analysis, high genetic similarity was observed between samples from the Podyjí NP and Hřebečský ridge. The impact of the analysis results on the conservation management of tested populations was outlined.

Squash vein yellowing virus from California emerged in the Middle East via intragenic and intergeneric recombination events in the hypervariable potyvirus P1 and ipomovirus P1a genes.

We present the complete sequence of the genomic RNA of an isolate of squash vein yellowing virus (Ipomovirus cucurbitavenaflavi) from California (SqVYV-CA) and show it is a recombinant virus with a highly divergent 5' UTR and proximal P1a gene. The evolution of SqVYV-CA involved an intrageneric event between unknown potyviruses, related to isolates of papaya ringspot virus (Potyvirus papayanuli) from the Old World, and an intergeneric event between this recombinant potyvirus (minor parent) and an isolate of SqVYV from Israel (SqVYV-IL) (major parent). These events occurred in mixed infections and in the potyvirus P1 and ipomovirus P1a recombination hotspots and resulted in SqVYV-CA having a potyvirus 5' UTR and chimeric P1-P1a gene/protein and the remainder of the genome from SqVYV-IL. The SqVYV-CA chimeric P1-P1a gene is under positive selection, and the protein is intrinsically disordered and may localize to the nucleus via nuclear localization signals in the P1 part. The C-terminal SqVYV-IL P1a part also diverged but retained the conserved serine protease motif. Furthermore, substantial divergence in SqVYV isolates from the Middle East was associated with genetic drift and a long evolutionary history in this region. The finding that the host range and symptomatology in cucurbits of SqVYV-CA is similar to those of SqVYV from Florida and SqVYV-IL, indicated that the recombinant part of the genome had no obvious effect on the virus-host interaction. A divergent part of the P1 sequence of the SqVYV-CA P1-P1a gene was used to develop a primer pair and RT-PCR test for specific detection of SqVYV-CA. This test was used to detect spread of SqVYV-CA to a new production area of California in 2021 and 2022. Together, these results demonstrate (i) a high level of genetic diversity exists among isolates of SqVYV and involved intra- and intergeneric recombination and genetic drift (mutation), (ii) evidence that SqVYV originated in the Middle East and that there were independent introductions into the New World and (iii) the remarkable genetic flexibility of the 5' proximal genes of these viruses.

Characterization of Intsia spp. from Indonesia using microsatellite markers

Microsatellite DNA markers are known to have a high level of genetic diversity and can be used for various purposes. These include population genetic analysis, gene flow assessment, pollen distribution, parent analysis, and accurate distinction between types and varieties. Despite the potential application of microsatellite markers, their development process often requires high costs, energy, and time. To overcome the limitations, several studies have proposed the use of cross-species amplification, which has proven to be a cost and time-efficient method for obtaining species-specific DNA markers. Therefore, this study aimed to identify three species of Merbau in Indonesia, namely Intsia bijuga, I. palembanica, and I. acuminata using cross-species amplification. The three species are known to exhibit similarities in all taxonomical characteristics except for minor differences in the number of leaf pairs per twig and the tip shape of the leaflets. These species also have different levels of economic value and conservation status due to variations in the type of wood produced. Several studies have shown that identification errors can affect the economic value of their wood and logging mistakes can lead to a decrease in the genetic diversity. To address the concerns, Intsia bijuga and I. acuminata from Indonesia were selected as test samples for the cross-amplification of microsatellite markers created for I. palembanica. Due to their taxonomical similarities, the diagnostic characteristics of each Intsia species were assessed based on microsatellite markers. Leaf samples were obtained from three species of Intsia that had been verified and identified based on morphological characteristics by taxonomists from the Bogor Botanical Garden Indonesia. In addition, a total of 10 polymorphic I. palembanica microsatellite markers from the previous literature were used in this study. The results showed that the cross-species amplification of microsatellite locus was successful in all markers. Certain alleles were also observed to be shared by the three species of Intsia, while some were specific to a particular species. These specific alleles could also serve as a diagnostics characteristic for Intsia spp. In addition, a set of polymorphic microsatellites showing a successful transfer across species of Intsia could serve as a valuable tool for comparative studies among related taxa species and breeding and conservation programs.