High Level Of Genetic Diversity Research Articles

Molecular evidence for multiple origins and high genetic differentiation of non-native winter crane fly, Trichocera maculipennis (Diptera: Trichoceridae), in the maritime Antarctic

Native biodiversity and ecosystems of Antarctica safeguarded from biological invasion face recent threats from non-native species, accelerated by increasing human activities and climate changes. Over two decades ago, the winter crane fly, Trichocera maculipennis, was first detected on King George Island. It has now successfully colonized several research stations across King George Island. To understand the origin, genetic diversity, and population structure of this Holarctic species, we conducted mitochondrial DNA cytochrome c oxidase subunit I (COI) sequence analysis across both its native and invasive ranges. In parallel, we performed microsatellite loci analysis within the invasive ranges, utilizing 12 polymorphic microsatellite markers. Furthermore, we compared body sizes among adult males and females collected from three different locations of King George Island. Our COI sequence analysis exhibited two different lineages present on King George Island. Lineage I was linked to Arctic Svalbard and Polish cave populations and Lineage II was related to Canadian Terra Nova National Park populations, implying multiple origins. Microsatellite analysis further exhibited high levels of genetic diversity and significant levels of genetic differentiation among invasive populations. Body sizes of adult T. maculipennis were significantly different among invasive populations but were not attributed to genetics. This significant genetic diversity likely facilitated the rapid colonization and establishment of T. maculipennis on King George Island, contributing to their successful invasion. Molecular analysis results revealed a substantial amount of genetic variation within invasive populations, which can serve as management units for invasive species control. Furthermore, the genetic markers we developed in the study will be invaluable tools for tracking impending invasion events and the travel routes of new individuals. Taken together, these findings illustrate the highly invasive and adaptable characteristics of T. maculipennis. Therefore, immediate action is necessary to mitigate their ongoing invasion and facilitate their eradication.

Diversity analysis of southern African Artemisia afra using a single nucleotide polymorphism derived from diversity arrays

Artemisia afra is an aromatic shrub used as a herbal remedy in southern Africa for various disorders, including coughs, colds, influenza, and, most notably, for the prophylaxis and treatment of Plasmodium falciparum infections. Modern high-throughput genotyping by sequencing, which combines next generation sequencing and diversity array technology (DArTseq) complexity reduction methods, allows for the generation of high-quality whole-genome profiles without any previous organismal genetic information that may hamper the diversity analyses. This study investigated the feasibility of incorporating DArTseq-derived single-nucleotide polymorphisms (SNPs) and bioactive compounds into a geographic information system to predict the spatial distribution of A. afra gene diversity in selected southern African environs. DNA extraction, sequencing, and SNP calling mineral analyses (using R Studio) were performed on a total of 80 genotypes collected around Roma and Mohale’s Hoek, Lesotho, and Wepener and Hobhouse, South Africa. The unweighted pair group method with arithmetic mean (UPGMA) and neighbour-joining dendrograms revealed three clusters of variation among genotypes; however, geographic distribution did not influence A. afra genetic diversity. The mean heterozygosity among genotypes was 7.7%. Genotypes collected in Roma and Mohale’s Hoek exhibited high levels of genetic diversity. Local A. afra genetic diversity was relatively low, indicating uniformity of subspecies per locality. The diversity among genotypes indicated that A. afra SNPs may occur despite the location. Given that genetic diversity enhances crop performance, our findings can be useful in germplasm management, industries producing by-products of A. afra, and plant breeding programs. For the long-term conservation of medicinal plants in South Africa, significant sampling and regional data are required. In addition to evaluating qualitative and quantitative assessments of phytochemicals, it is necessary to evaluate foliar mineral composition, as well as the agronomic and morphological characteristics of collected specimens from studied locations.

Genotypic and antimicrobial susceptibility of Streptococcus agalactiae causing bovine mastitis in the central region of Thailand.

Streptococcus agalactiae is a highly contagious pathogen that causes bovine mastitis, leading to significant economic losses. This study aimed to (1) identify and characterize S. agalactiae strains responsible for bovine mastitis by examining their phenotypic and genotypic characteristics in Thai dairy-intensive farming areas and (2) determine their susceptibility profiles to antimicrobial agents. In total, 100 S. agalactiae isolates obtained from clinical and subclinical mastitis cases from 13 dairy herds located in the central region of Thailand were examined. To confirm the identity of the bacterial pathogens, conventional microbiological procedures recommended by the National Mastitis Council (NMC) and the VITEK® 2 system were employed. All 100 isolates were successfully identified as S. agalactiae using the NMC procedure, whereas 94 isolates were identified as S. agalactiae using the VITEK® 2 system. Finally, the S. agalactiae-specific gene dlt S was identified in all the examined isolates using polymerase chain reaction. Capsular polysaccharide (CPS) typing revealed that all strains belonged to CPS type Ia. Multilocus sequence typing identified 33 selected isolates as sequence type 103. Random amplified polymorphic DNA (RAPD) typing yielded 43 RAPD types, with 6 RAPD clusters identified. These results demonstrated a high level of genetic diversity among S. agalactiae within the studied herds. RAPD analysis suggested that specific S. agalactiae strains could persist in dairy farms for 2-12 months. Furthermore, antimicrobial susceptibility testing was performed using the broth microdilution method. Most strains demonstrated susceptibility to ampicillin, penicillin, penicillin/novobiocin, cephalothin, oxacillin, ceftiofur, and erythromycin. This study revealed the phenotypic and genotypic characteristics of S. agalactiae isolates responsible for bovine mastitis in the central region of Thailand. The rapid identification of S. agalactiae and application of molecular typing methods can provide valuable epidemiological information regarding S. agalactiae causing mastitis in dairy farms. The antimicrobial susceptibility of S. agalactiae indicates that antimicrobial treatment for control and eradication could be a successful protocol. Our findings revealed that a single clonal strain of S. agalactiae affected the 13 studied farms. Further research is needed to explore the feasibility of vaccine development and application.

Genetic diversity of the submerged macrophyte Ceratophyllum demersum depends on habitat hydrology and habitat fragmentation.

The adaptability of plant populations to a changing environment depends on their genetic diversity, which in turn is influenced by the degree of sexual reproduction and gene flow from distant areas. Aquatic macrophytes can reproduce both sexually and asexually, and their reproductive fragments are spread in various ways (e.g. by water). Although these plants are obviously exposed to hydrological changes, the degree of vulnerability may depend on the types of their reproduction and distribution, as well as the hydrological differences of habitats. The aim of this study was to investigate the genetic diversity of the cosmopolitan macrophyte Ceratophyllum demersum in hydrologically different aquatic habitats, i.e. rivers and backwaters separated from the main river bed to a different extent. For this purpose, the first microsatellite primer set was developed for this species. Using 10 developed primer pairs, a high level of genetic variation was explored in C. demersum populations. Overall, more than 80% of the loci were found to be polymorphic, a total of 46 different multilocus genotypes and 18 private alleles were detected in the 63 individuals examined. The results demonstrated that microsatellite polymorphism in this species depends on habitat hydrology. The greatest genetic variability was revealed in populations of rivers, where flowing water provides constant longitudinal connections with distant habitats. The populations of the hydrologically isolated backwaters showed the lowest microsatellite polymorphism, while plants from an oxbow occasionally flooded by the main river had medium genetic diversity. The results highlight that in contrast to species that spread independently of water flow or among hydrologically isolated water bodies, macrophytes with exclusive or dominant hydrochory may be most severely affected by habitat fragmentation, for example due to climate change.

Effects of climatic fluctuations on the fragmented distribution pattern of a Tertiary relict plant, Pseudotaxus chienii (Taxaceae), in subtropical China

Abstract Habitat fragmentation can facilitate local adaptation of species to heterogeneous environments and affect population demographic history. To understand the factors influencing evolutionary dynamics, such as climatic fluctuations and complex geomorphological features, we used 18 chloroplast microsatellites, 15 nuclear microsatellites, three chloroplast fragments, and two nuclear regions to explore the genetic structure and phylogeographical history of Pseudotaxus chienii. Furthermore, its current and past distributions were constructed based on ecological niche modelling. Moderate to high levels of genetic diversity were found at the species level. Precipitation was a decisive factor influencing the genetic structure of P. chienii. In addition, local adaptation to heterogeneous environments also contributed to maintain the fragmented distribution. Finally, incomplete lineage sorting led to the cyto-nuclear discordance. Overall, we show that pre-Quaternary and Quaternary climatic fluctuations and restricted gene flow exerted significant effects on the formation and maintenance of the fragmented distribution of P. chienii. The study provides new insights into the evolutionary history of plants in subtropical China.

A high level of genetic divergence between Exserohilum turcicum populations from maize and sorghum in Henan province of China revealed by SSR markers

AbstractExserohilum turcicum is the causative agent of northern leaf blight of maize and sorghum. Although host specificity of E. turcicum has been observed from isolates collected from maize and sorghum, limited molecular evidence has been presented so far for the formation of formae speciales. In this study, 15 simple‐sequence repeat (SSR) markers were used to study genetic diversity and population structure of 60 E. turcicum isolates from maize and sorghum in Henan province of China. A total of 54 haplotypes were identified from all isolates, in which 29 haplotypes were unique to the maize population and 25 were unique to the sorghum population. The phylogenetic tree showed that 60 isolates were clustered into two genetic groups; Group I consisted of 30 isolates from sorghum and Group II consisted of 30 isolates from maize. The formation of two groups was also supported by the result of principal component analysis. The analysis of population structure indicated that the main source of genetic compositions was completely different between the maize and sorghum populations. The fixation index (FST) and gene flow (Nm) between the two populations were 0.184 and 1.111, respectively. The analysis of molecular variance demonstrated that 27% and 73% of the total variation were distributed between and within the two populations, respectively. These findings reveal a high level of genetic divergence between E. turcicum populations associated with maize and sorghum and advance our understanding of the molecular basis underlying host specificity of E. turcicum.

10 What Role Could Old/Heritage Genetics Play in Climate adaptation?

Abstract Creole or Criollo breeds descend directly from cattle introduced by the Spanish and Portuguese conquerors in the XVth century, being the only cattle breeds in the Americas that have endured 500 years of natural selection to local conditions. Their genetic background includes Iberian and African taurine breeds. This ancestry combined with local adaptations to a very wide variety of environments throughout all the continent created the wide spectrum of American Criollo breeds that we see today, from USA to the Patagonian region. Criollo cattle was the basis of colonial times livestock industry until they were displaced by more specialized European and cebuine type cattle breeds at the end of the 19th century. Efforts by local producers and research institutions helped to preserve Criollo populations and to avoid their extinction. Most of Criollo animals were relegated to marginal regions unsuitable for commercial breeds, which reinforced their ability to adapt to unfavorable environments. Their adaptation to different environments allowed the expression of high levels of genetic variability, being a source of hidden alleles of potential use in animal production and thus very important to study and preserve. The analysis of nuclear and cytoplasmic markers, such as SNP, microsatellites and mitochondrial DNA, has allowed estimations of genetic diversity, admixture events with other breeds, and the elucidation of genetic relationships within Criollo breeds and with European and African breeds. Criollo breeds differ considerably from each other, and most have their own identity or group with others from neighboring regions. These results indicate that Criollo breeds represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these heritage breeds to minimize inbreeding and uncontrolled crossbreeding. Several studies have demonstrated that these animals can produce high quality meat, are more resistant to diseases and heat stress, and emphasize their high fertility, calving ease, longevity and ability to adapt to harsh environments, including arid regions. More studies are needed to elucidate the genetic basis of these traits. Properly managed, Criollo cattle “old genetics” can certainly be part of the solution to modern livestock production problems.

Genetic diversity of a short-ranged endemic terrestrial snail.

The factors that influence population structure and connectivity are unknown for most terrestrial invertebrates but are of particular interest both for understanding the impacts of disturbance and for determining accurate levels of biodiversity and local endemism. The main objective of this study was to determine the historical patterns of genetic differentiation and contemporary gene flow in the terrestrial snail, Austrochloritis kosciuszkoensis (Shea & O. L. Griffiths, 2010). Snails were collected in the Mt Buffalo and Alpine National Parks in Victoria, in a bid to understand how populations of this species are connected both within continuous habitat and between adjacent, yet separate environments. Utilising both mitochondrial DNA (mtDNA) and single nucleotide polymorphism (SNP) data, the degree of population structure was determined within and between sites. Very high levels of genetic divergence were found between the Mt Buffalo and Alpine snails, with no evidence for genetic exchange detected between the two regions, indicating speciation has possibly occurred between the two regions. Our analyses of the combined mtDNA and nDNA (generated from SNPs) data have revealed patterns of genetic diversity that are consistent with a history of long-term isolation and limited connectivity. This history may be related to past cycles of changes to the climate over hundreds of thousands of years, which have, in part, caused the fragmentation of Australian forests. Within both regions, extremely limited gene flow between separate populations suggests that these land snails have very limited dispersal capabilities across existing landscape barriers, especially at Mt Buffalo: here, populations only 5 km apart from each other are genetically differentiated. The distinct genetic divergences and clearly reduced dispersal ability detected in this data explain the likely existence of at least two previously unnamed cryptic Austrochloritis species within a 30-50 km radius, and highlight the need for more concentrated efforts to understand population structure and gene flow in terrestrial invertebrates.

Molecular phylogeography and historical demography of a widespread herbaceous species from eastern North America, Podophyllum peltatum.

Glacial/interglacial cycles and topographic complexity are both considered to have shaped today's diverse phylogeographic patterns of taxa from unglaciated eastern North America (ENA). However, few studies have focused on the phylogeography and population dynamics of wide-ranging ENA herbaceous species occurring in forest understory habitat. We examined the phylogeographic pattern and evolutionary history of Podophyllum peltatum L., a widely distributed herb inhabiting deciduous forests of ENA. Using chloroplast DNA (cpDNA) sequences and nuclear microsatellite loci, we investigated the population structure and genetic diversity of the species. Molecular dating, demographic history analyses, and ecological niche modeling were also performed to illustrate the phylogeographic patterns. Our cpDNA results identified three main groups that are largely congruent with boundaries along the Appalachian Mountains and the Mississippi River, two major geographic barriers in ENA. Populations located to the east of the Appalachians and along the central Appalachians exhibited relatively higher levels of genetic diversity. Extant lineages may have diverged during the late Miocene, and range expansions of different groups may have happened during the Pleistocene glacial/interglacial cycles. Our findings indicate that geographic barriers may have started to facilitate the population divergence in P. peltatum before the Pleistocene. Persistence in multiple refugia, including areas around the central Appalachians during the Quaternary glacial period, and subsequent expansions under hospitable climatic condition, especially westward expansion, are likely responsible for the species' contemporary genetic structure and phylogeographic pattern.

Construction of a genome-wide SSR marker library in Gerbera hybrida: Insights into genetic variation and germplasm resources

Gerbera hybrida is a highly sought-after cut flower globally, renowned for its diverse flower color and pattern resulting from its complex inflorescence meristem architecture. However, the scarcity of genomic information and molecular markers has impeded efforts to comprehend the genetic diversity of G. hybrida. To address this, our study aimed to construct genome-wide simple sequence repeat (SSR) markers in G. hybrida, utilizing genomic data from an inbred line. We employed 170 gerbera cultivars exhibiting distinct flower patterns and colors to analyze genetic variation and diversity. Our analyses revealed highly polymorphic SSR markers, a total of 69 alleles (Na) were amplified by 14 pairs of primers, in which polymorphic information content (PIC) ranging from 0.380 to 0.700 with an average value of 0.583. The polymorphic results of the observed heterozygosity (Ho) and Shannon's information index (I) were 0.499 and 1.195, respectively, showing a high level of genetic diversity within the enriched sequences of the G. hybrida genome. Leveraging these markers with strong differentiation, we successfully constructed a unique fingerprint map encompassing 170 gerbera germplasm lines. This study involved the construction of an SSR fingerprint library for G. hybrida germplasm resources, employing genetic analysis for screening and molecular-level identification. The findings provide valuable insights into the identification of gerbera germplasm resources and kinship studies among various groups. Moreover, this study lays a solid foundation for future advancements in molecular design breeding improvement and germplasm resource development in G. hybrida.

Genetic Diversity and Phylogenetic Relationships of Mountain Papaya (Vasconcellea pubescens) in Dieng Plateau Based on Internal Transcribed Spacer Sequence

The Dieng Plateau is an area used to cultivate Mountain Papaya (<em>Vasconcellea pubescens</em> A.DC.) as a food commodity in Indonesia. Research on diversity and relationships is vital as a first step in Mountain Papaya conservation in the Dieng Plateau. The study aims to determine the genetic diversity and relationship between Mountain Papaya accessions using Internal Transcribed Spacer (ITS) rDNA sequences. Fourteen accessions of Mountain Papaya with different sex distributions and altitudes are amplified using ITS1 and ITS4 primers. The genetic diversity is analyzed using the DnaSP 5.10.1 program. The Maximum Likelihood (ML) approach in MEGA 11 is utilized for assessing phylogenetic tree data based on ITS-rDNA regional sequences. With high haplotype diversity (Hd) values of 1.000 ± 0.027 and high nucleotide diversity (π) values of 0.09674 ± 0.00978, Mountain Papaya exhibits a high level of genetic diversity. Three main clades were identified in the phylogram tree based on the 14 ITS-rDNA sequences of Mountain Papaya. The results of this diversity data can support breeding programs intended to boost Mountain Papaya variety production.

Analysis of Genetic Diversity and Construction of a Core Collection of Ginkgo biloba Germplasm Using EST-SSR Markers

Understanding genetic diversity and population structure is essential for the conservation and utilization of germplasm. Ginkgo biloba L. is a medicinal, edible and ornamental tree species. Detailed knowledge of genetic variability and diversity in different Ginkgo germplasm resources is still scarce. In this study, a total of 173,160 Expressed Sequence Tag Simple Sequences Repeat (EST-SSR) loci were derived from 43,073 Unigenes of the Ginkgo genome. A total of 43,731 pairs of specific primers were designed for the EST-SSR loci, with sequence lengths >20 bp, and 100 of the SSR primers were randomly selected. Among these, 20 EST-SSR markers were verified and used to assess the genetic diversity of 101 Ginkgo individuals collected from different regions. The average values for Shannon’s diversity index (I, 0.993), expected heterozygosity (0.566) and Nei’s genetic diversity index (H, 0.563) indicate a high level of genetic diversity of Ginkgo populations. Based on the EST-SSR markers, a core collection of Ginkgo germplasm comprising 27 genetic resources was constructed. The retention rates of the number of resources, the number of alleles, the number of effective alleles, the I index, the H index and the percentage of polymorphic loci of the constructed core collection are 26.73%, 95.29%, 103.43%, 102.25%, 102.91% and 100.00%, respectively. The molecular markers developed in this study are an effective tool for Ginkgo genetic diversity analysis and will facilitate the future breeding of this species.

The genetic diversity and population structure of Macridiscus multifarius along the coast of China using IIB-RAD sequencing

Abstract The clam Macridiscus multifarius is ecologically and economically important in the coastal regions of China. In this study, the IIB-RAD method was used to investigate the population diversity and structure of M. multifarius along the coast of China. Genomic DNA was extracted, sequenced, and subjected, resulting in 110.88 Gb of clean reads. Analysis showed that the M. multifarius populations along the coast of China exhibited a moderate to high level of genetic diversity (mean: HO = 0.272, HE = 0.365, π = 0.390, and FIS = 0.268). Further analysis of high-quality single nucleotide polymorphisms was used to generate a maximum-likelihood phylogenetic tree, principal component analysis, and FST values. The results revealed that there is no notable genetic differentiation among the nine M. multifarius populations south of the Yangtze River estuary. However, the Yancheng population shows clear genetic differentiation compared with the other nine populations, possibly linked to the barrier effect of the Yangtze dilution water and ocean current system. We believe that these results provide genetic insights for fisheries management to plan fisheries policies for M. multifarius and conserve natural resources.

Episodic population fragmentation and gene flow reveal a trade-off between heterozygosity and allelic richness.

In episodic environments like deserts, populations of some animal species exhibit irregular fluctuations such that populations are alternately large and connected or small and isolated. Such dynamics are typically driven by periodic resource pulses due, for example, to large but infrequent rainfall events. The repeated population bottlenecks resulting from fragmentation should lower genetic diversity over time, yet species undergoing these fluctuations appear to maintain high levels of genetic diversity. To resolve this apparent paradox, we simulated a metapopulation of constant size undergoing repeat episodes of fragmentation and change in gene flow to mimic outcomes experienced by mammals in an Australian desert. We show that episodic fragmentation and gene flow have contrasting effects on two measures of genetic diversity: heterozygosity and allelic richness. Specifically, fragmentation into many, small subpopulations, coupled with periods of infrequent gene flow, preserves allelic richness at the expense of heterozygosity. In contrast, fragmentation into a few, large subpopulations maintains heterozygosity at the expense of allelic richness. The strength of the trade-off between heterozygosity and allelic richness depends on the amount of gene flow and the frequency of gene flow events. Our results imply that the type of genetic diversity maintained among species living in strongly fluctuating environments will depend on the way populations fragment, with our results highlighting different mechanisms for maintaining allelic richness and heterozygosity in small, fragmented populations.

Genetic Diversity of Aspergillus flavus on Maize in Guatemala.

Aflatoxin contamination of maize is a leading threat to health in Guatemala. This contamination is the result of infection from Aspergillus flavus and has been effectively reduced in other countries through application of nonaflatoxigenic, indigenous strains of A. flavus. We collected 82 maize samples from throughout Guatemala in two years and isolated 272 A. flavus from these samples, including 126 unique genotypes. We provide here a phenotypic and simple sequence repeat (SSR)-based genotypic description of these isolates, as well as an analysis of the diversity of this population. High levels of genetic diversity were observed with the nonaflatoxigenic isolates in this study, but this information contributes to the development of indigenous aflatoxin biocontrol products.

Assessing the conservation impact of Chinese indigenous chicken populations between ex-situ and in-situ using genome-wide SNPs

Conservation programs require rigorous evaluation to ensure the preservation of genetic diversity and viability of conservation populations. In this study, we conducted a comparative analysis of two indigenous Chinese chicken breeds, Gushi and Xichuan black-bone, using whole-genome SNPs to understand their genetic diversity, track changes over time and population structure. The breeds were divided into five conservation populations (GS1, 2010, ex-situ; GS2, 2019, ex-situ; GS3, 2019, in-situ; XB1, 2010, in-situ; and XB2, 2019, in-situ) based on conservation methods and generations. The genetic diversity indices of three conservation populations of Gushi chicken showed consistent trends, with the GS3 population under in-situ strategy having the highest diversity and GS2 under ex-situ strategy having the lowest. The degree of inbreeding of GS2 was higher than that of GS1 and GS3. Conserved populations of Xichuan black-bone chicken showed no obvious changes in genetic diversity between XB1 and XB2. In terms of population structure, the GS3 population were stratified relative to GS1 and GS2. According to the conservation priority, GS3 had the highest contribution to the total gene and allelic diversity in GS breed, whereas the contribution of XB1 and XB2 were similar. We also observed that the genetic diversity of GS2 was lower than GS3, which were from the same generation but under different conservation programs (in-situ and ex-situ). While XB1 and XB2 had similar levels of genetic diversity. Overall, our findings suggested that the conservation programs performed in ex-situ could slow down the occurrence of inbreeding events, but could not entirely prevent the loss of genetic diversity when the conserved population size was small, while in-situ conservation populations with large population size could maintain a relative high level of genetic diversity.

Genetic diversity and molecular analysis using RAPD markers of banana cultivars in the five regions of East Java, Indonesia

Abstract. Slameto. 2023. Genetic diversity and molecular analysis using RAPD markers of banana cultivars in the five regions of East Java, Indonesia. Biodiversitas 24: 5035-5043. The study explored banana plants in East Java, Indonesia, specifically in the districts of Jember, Banyuwangi, Bondowoso, Situbondo, and Lumajang, using Random Amplified Polymorphic Deoxyribonucleic Acid (RAPD) markers. Thirty accessions of Musa ssp. were collected from these five districts, revealing a high level of genetic diversity. Primers OPA-04 and OPC-05 were suitable for assessing genetic variation in banana plants. It was found that the OPD-07 primer produced the fewest DNA bands (8 bands and 7 polymorphic bands), while the OPA-04 primer produced the maximum number of DNA bands (14 bands, with 9 polymorphic bands). The OPB-08 primer had the lowest polymorphism percentage (56%), and the OPC-05 primer had the greatest percentage (92%). With genetic similarity scores ranging from 0.04 (Bigih Tanjung Glugur and Lilin Banyuwangi) to 0.94 (Agung Banyuwangi and Let). The phylogenetic tree of 30 banana plants formed two primary clusters: cluster I and II, included 26 and 4 banana varieties respectively. In addition, molecular variance (AMOVA) resulted a significant proportion (93%) of genetic diversity within the population. Further studies using more precise genetic markers are still needed to determine the exact identity of the banana plant genome.

Population genetics of Leptoglossus clypealis (Hemiptera: Coreidae) in the Western United States.

The leaffooted bug, Leptoglossus clypealis Heidemann, is a seed-feeding economic pest of crops including almonds and pistachios. The historical distribution of L. clypealis has been considered to be West of the Mississippi in the United States. L. clypealis was recently found in sorghum in the Coastal Bend of Texas, representing a new host record and new collection locality. This study investigated the genetic diversity of L. clypealis museum voucher samples from the Western United States (i.e., Texas, California, and Idaho) collected from 1994 to 2019, including the L. clypealis samples from the Coastal Bend. Eleven new sequences were obtained. Sample sequences were compared with public sequences of L. clypealis from the Western United States. The mitochondrial DNA cytochrome oxidase 1 (mtDNA COI) barcode gene region revealed differences among and within the collection regions. Texas, Idaho, and California all had samples with unique genotypes, and the combined dataset had a haplotype diversity of 1.0. The Texas specimens recently collected in the Coastal Bend did not match genotypes from California or Idaho, and it is unlikely they were recently introduced. Overall, L. clypealis from Texas, Idaho, and California have a high level of genetic diversity, and the 3 regions appear to be within the native range of the species.

Genetic diversity and salt tolerance assessment of 51 alfalfa (Medicago sativa) varieties under saline soil conditions

IntroductionSalt stress significantly impacts plant growth worldwide. Although alfalfa exhibits some tolerance to salt-alkali soils, the specific salt tolerance levels across different alfalfa varieties remain inadequately understood. For this purpose, we conducted a study to investigate the diversity of agronomic traits of alfalfa (Medicago sativa) under different soil environments in order to elucidate the salt tolerance of 51 alfalfa varieties.MethodsWe chose three different soil conditions for our study: normal conditions in Yantai as control, saline conditions in Yantai with soil salt concentrations ranging from 0.25 to 0.33%, and saline-alkali conditions in Dongying with soil salt concentrations ranging from 0.28 to 0.32%. We chose 51 alfalfa varieties from different sources as our experimental materials. Planting was conducted following a completely randomized block design with three replicates for each variety. Harvesting was performed when the plants reached 50% flowering, cutting them at a height of 5 cm above the ground. Comprehensive assessments encompassed 10 parameters, namely fresh weight, dry weight, stem-leaf ratio, branch count, plant height, crude protein content, crude fat content, acid detergent fiber, neutral detergent fiber, and ash content.ResultsOur findings revealed that the 51 studied alfalfa varieties displayed significant generalized heritability and coefficient of variation, indicating a high level of genetic diversity. Using principal component and cluster analyses, we categorized the varieties into three distinct clusters based on their agronomic traits. Grey correlation degree analysis revealed the commendable performance of Ying st, PI 672734, and Mei zuo across diverse environments. Genotype emerged as a predominant determinant of all parameters, except crude fat, acid detergent fiber, and neutral detergent fiber. Through the application of membership function analysis, PI 672768 emerged as a variety that demonstrated strong tolerance in both saline soil contexts.DiscussionDespite extensive previous studies indicating Zhong Mu No. 1 as a salt-tolerant alfalfa variety, its performance in this experiment did not distinguish itself. The findings of this study provide a fundamental basis for improving the management of saline-alkali lands and advancing alfalfa cultivation practices.

Genetic characterization of superior durian (Durio zibethinus L.) accessions in Batang District, Central Java, Indonesia based on ISSR markers

Abstract. Amrullah MI, Rahayu ES, Puwantoyo E, Maharani RI, Solichin, Sriyadi, Hadiprasetya TY, Retnoningsih A. 2023. Genetic characterization of superior durian (Durio zibethinus L.) accessions in Batang District, Central Java, Indonesia based on ISSR markers. Biodiversitas 24: 4811-4819. Durian (Durio zibethinus L.) has the highest level of genetic diversity in the genus of Durio. The genetic diversity of D. zibethinus in Batang District, Central Java, Indonesia needs to be explored to obtain data on superior durian accessions that are adaptive in the area. This study aimed to analyze the genetic diversity of 40 superior durian accessions from 13 locations in Batang District using 10 Inter Simple Sequence Repeat (ISSR) primers. Genomic DNA was isolated from leaves using a modified CTAB method. PCR products were electrophoresed on 2% agarose and yielded 161 ISSR alleles with a percentage of 100% polymorphic alleles. The level of genetic diversity based on Nei's gene diversity and Shannon's Information index are 0.277 and 0.434, respectively. The durian accessions studied have a similarity coefficient of 0.22-0.86 and are divided into two main clusters. Siwatu 1 and Siwatu 2 accessions have the highest genetic similarity coefficient (0.86), while Butternuts and Watu Tembogo 1 accessions show the lowest genetic similarity coefficient (0.05). Specific alleles were found in 11 durian accessions. The molecular characterization results show the high genetic diversity of superior durian accessions in Batang District and add to the list of local superior durian accessions in Indonesia.