High Intrapopulation Research Articles

Reproductive characteristics of indigenous village chickens

BackgroundIndigenous village chickens (IVCs) show a wide variation in production performance and reproductive characteristics. This high variation is occurred due to genetic and environmental factors and gene-environment interactions.ResultsThis work reports the results of a cross-sectional study conducted using a face-to-face interview with 119 small-scale farmers regarding their insights on the production performance and reproductive characteristics of IVCs. It was reported that pullets were sexually mature on average at the age of 5.5 months and cockerels at 6 months. This comparatively early sexual maturity by the standards of IVCs might be associated with the impact of uncontrolled gene flow from production breeds. However, there is high variation in age at sexual maturity at an individual bird’s level. It was found that pullets mature earlier than cockerels (t = 3.250, df = 159, p = 0.001, 95% CI: -0.670, -0.166). According to the respondents, local hens laid on average 14 eggs per clutch. The average number of clutches per year was 4, which can culminate in the yearly production of 56 eggs. A significantly large proportion of the respondents reported that the dry season is appropriate for laying eggs (96.7%) and brooding chicks (94.1%). During the dry season, the scavenging feed resource is relatively abundant, the risk of infection is comparatively low, and the hot weather is suitable for laying eggs and brooding chicks. IVCs possess a long reproductive lifetime, that is, on average, 3 years in hens and 2 years in cocks, which makes them more productive than has been anticipated. For example, this study found that a hen, on average, can lay 174 eggs and hatch 58 chicks in its average reproductive lifetime of 3 years.ConclusionsThe high intrapopulation variation in the reproductive performance of IVCs is vital resource in genetic improvement programs.

Pollen reaction of mutant tomato forms to abiotic stress factors

The article presents the results of screening accessions of the mutant tomato gene pool (125 genotypes) based on the response of their pollen to abiotic stress factors (high, low temperatures, drought) in order to study their potential and identify genetic sources/donors of resistance. The studies were carried out in open ground conditions from 2015 to 2017 and in summer greenhouses from 2017 to 2019. High heterogeneity of the genotype-specific response of pollen of mutant forms to various stress factors was shown: with a lethal outcome to all factors (10 genotypes); highly resistant to all stressors (20 genotypes); combining resistance: to high and low temperatures (7 genotypes), to high temperature and drought (9 genotypes), to cold and drought (4 genotypes); resistant only: to high (14 genotypes) or low (17 genotypes) temperatures, drought (6 genotypes). Mutant forms (38 genotypes) with high intrapopulation variability in pollen germination and the ability to form long pollen tubes under various stressors were also identified. It was established that resistance to heat, cold and drought according on traits of the male gametophyte was determined by different genetic systems.

Genetic diversity of broomrape (Orobanche cumana Wallr.) populations from different geographical origins assessed by ISSR markers

Abstract The present study was focused on the assessment of genetic diversity in twenty-three populations of Orobanche cumana parasitizing on sunflower in Bulgaria, Turkey, Moldova and Romania using 13 ISSR markers. The obtained results on the genetic diversity parameters showed that the broomrape populations were characterised by a significant level of the intrapopulation diversity. In addition, descriptive population genetic statistics revealed that Turkish populations had a higher level of genetic diversity indices than populations from several areas of the northeast and east of the Balkan Peninsula included in Eastern Europe. The analysis of molecular variance showed that 38 % of the genetic variability was due to differences within populations, 34 % was due to differences among populations and the lowest molecular variation was among countries (28 %). According to clustering and PCA methods, Moldavian, Bulgarian and Romanian broomrapes shared more genetic traits with each other than with Turkish populations within a main gene pool. As a whole, all results of this study showed that there is a high intrapopulation diversity of the O. cumana gene pool in the Black Sea basin. From the clustering and PCA analyses, it can be concluded that the grouping of broomrape populations is partly determined by their geographical origin, as well as by the genetic differences and similarities accumulated over time, and is not related to virulence. The information obtained from this study may be highly relevant in contributing to the development of sustainable control strategies of the pathogen and breeding programmes for sunflower resistance to broomrape.

Phenotypic plasticity in Pinus canariensis seedlings growing at chilling and freezing temperatures

Global change is affecting the frequency and temporal distribution of frost events. We can expect damage caused by low temperatures to increase specially at the upper limit of a species’ elevation range. Here, we assessed how Pinus canariensis two-year old seedlings from different islands and elevations responded differently to chilling and freezing temperatures. Seedlings from six populations were grown either in a greenhouse (tmin = 5 ̊C, chilling conditions) or outdoors (tmin = −3.3 ̊C, freezing conditions) for 104 days in winter. Seedlings from one of these populations belonged to three half-sib families. Maximum quantum yield of Photosystem II and evapotranspiration (ETP) were determined four times throughout the study. All populations suffered photoinhibition under freezing but not under chilling conditions. We measured the lowest ETP in the population from the warmest and driest environment and lowest elevation (250 m) both under chilling and freezing conditions. The three populations from the higher elevations reached the highest ETP under chilling, a likely adaptation to the shortening of the vegetative period. The effect of elevation remained elusive for other parameters, which could be partly attributed to high intrapopulation variability. Epicuticular wax concentration increased and needle water content decreased in plants growing outdoors. All populations except the one most affected by cold dehydration showed osmotic adjustment and a simultaneous decrease in tissue elasticity under freezing. This response was stronger in the population from the highest elevation (2,241 m). Our results highlight the coexistence of adaptive processes, genetic variation and plasticity conditioning the response to low temperatures in this species.

Phenotypic plasticity of growth ring traits in Pinus hartwegii at the ends of its elevational gradient.

Phenotypic plasticity (PP) could be an important short-term mechanism to modify physiological and morphological traits in response to climate change and global warming, particularly for high-mountain tree species. The objective was to evaluate PP response of growth ring traits to temperature and precipitation in Pinus hartwegii Lindl. populations located at the ends of its elevational gradient on two volcanic mountains in central Mexico (La Malinche and Nevado de Toluca). Increment cores collected from 274 P. hartwegii trees were used to estimate their PP through reaction norms (RN), which relate the ring width and density traits with climate variables (temperature and precipitation). We estimated the trees' sensitivity (significant RN) to climatic variables, as well as the relative proportion of RN with positive and negative slope. We also estimated the relationship between the PP of ring width and density traits using correlation and Principal Component (PC) analyses. Over 70% of all trees showed significant RN to growing season and winter temperatures for at least one growth ring trait, with a similar proportion of significant RN at both ends of the gradient on both mountains. Ring width traits had mostly negative RN, while ring density traits tended to have positive RN. Frequency of negative RN decreased from lower to higher elevation for most traits. Average PP was higher at the lower end of the gradient, especially on LM, both for ring width and ring density traits, although high intrapopulation variation in PP was found on both mountains. Results indicate that P. hartwegii presents spatially differentiated plastic responses in width and density components of radial growth. PP was particularly strong at the lower elevation, which has higher temperature and water stress conditions, putting these populations at risk from the continuing global warming driven by climate change.

Comparative analysis of genetic polymorphism in <i>Rhaponticum carthamoides</i> (Asteraceae) populations by ISSR markers in the Altai Republic

Background. Rhaponticum carthamoides (Willd.) Iljin (Asteraceae) is a rare species for the Altai Republic (AR). The purpose of this study was to characterize the genetic polymorphism of Rhaponticum carthamoides at the inter- and intrapopulation level in a comparative analysis for subsequent selection of seed samples from the genetically most heterogeneous natural populations of the AR for practical purposes. Materials and methods. The species was studied for ISSR variability in five habitats in the AR. DNA from dried leaves of R. carthamoides was isolated using the STAB method. For testing seventeen ISSR primers were used, seven of which were selected as most informative ones. Results and conclusion. The analysis showed that individual plants from five cenopopulations (CP) were distributed into three groups of similarity on the dendrogram. A separate clade was formed by plant samples from two CPs of the Katun Nature Reserve (KNR). Samples of one of those CPs grew on well-warmed southern slopes and exhibited a higher genetic heterogeneity than the others. The highest intrapopulation and interpopulation similarity in the distribution of DNA fragments was also found in two CPs from habitats with the smallest geographic distance from each other. Representatives of a separate population, least in size and number of individuals in the KNR, showed a high level of similarity in the distribution of DNA fragments. Significantly lower coefficients of genetic similarity with other CPs were found in plants from a small isolated CP from the Shavlinsky Protected Area. It can be assumed that one of the main reasons for the least genetic similarity of this population with others is its location in the immediate vicinity of the foothill at the pass to Achik (Ongudaysky District; absolute height: 2300 masl). This location can be a limiting factor for the exchange of genetic information with individuals from other populations.

Dissecting a vegetable landrace: Components of variation in Spanish ‘Moruno’ tomatoes as a case studio

The variability of landraces is dissected and related to farmers' practices through surveys. Spanish 'Moruno' tomatoes, recognised for their excellent flavour, were selected as a case study. For this purpose, 30 populations were characterised in a four-year program. Higher intra-population than inter-population variability was found. Variability is generally reduced in the traits used by farmers as selection criteria. Farmers rarely used flavour as a selection criterion, but it is one of the main characteristics used by them to define the landrace. Seed exchange and growing different landraces simultaneously are commonplace, and outcrossing might occur, thus justifying in part the seed degeneration problems experienced by some farmers. At the same time, farmers select seeds for the next year on a per-fruit basis rather than a per-plant basis, justifying the maintenance of a high level of variability. In such cases, high pressure would be applied to key morphological traits but not to flavour. Accordingly, the sugars, acids and volatiles profiles related to flavour in the landraces' populations are highly variable, though the environment also exercises a high effect. It is necessary to make population selections to offer farmers materials combining the best organoleptic perception and a high stable yield. This would reduce the gap between the price premium received by farmers and the expected fair price. It would also be necessary to develop consumer information campaigns to exploit their willingness to pay for the extra value offered by landraces. Only then long-term on-farm conservation would be economically feasible. Although achieving a trade-off between yield and flavour is difficult, it is possible to identify populations that reach a compromise between them. In germplasm banks, it is impossible to evaluate all the materials in the same year. The use of hybrid controls, with no genetic variation, is helpful in considering the environmental effects. Still, genotype x environment interactions are evident, and using selected control populations of landraces is necessary to evaluate possible performances closer to the type of materials being evaluated.

SELEÇÃO DE ÁRVORES MATRIZES DE Handroanthus impetiginosus PARA SUBSIDIAR ÁREAS DE COLETA DE SEMENTES

ABSTRACT Handroanthus impetiginosus is a Brazilian native tree threatened by illegal logging that needs conservation strategies. Due to the need to obtain seeds of high genetic and physiological quality, this study aimed to select mother trees, aiming at the installation of Seed Collection Areas of H. impetiginosus. Therefore, the genetic diversity and physiological quality of seeds from 63 individuals of a natural population of H. impetiginosus in Rio Grande do Norte, Brazil, were evaluated. The molecular markers revealed that the studied population has high intrapopulation genetic diversity (Nei’s genetic diversity = 0.35; and Shannon index = 0.52). Subsequently, germination and seed vigor tests evaluated the physiological quality of seeds from 63 trees. Of this total, 45 individuals produced seeds of high and intermediate physiological quality. Therefore, individuals with a Nei’s genetic distance < 0.72 and germination greater than 50% can be selected as mother trees, and the population has the potential to propose a Seed Collection Area.

Delayed effect of thermal treatment on breaking physical seed dormancy: intrapopulation variation and implications for soil seed banks

Background Many studies have focused on the dormancy-breaking response to heat treatment of freshly matured seeds and immediately after thermal shock. Aims We evaluated whether the full effect of dry heat scarification in freshly matured seeds could be delayed over time and the possible influence of previous storage in the soil. Methods Adenocarpus argyrophyllus was the model species selected to explore our hypotheses by analysing the: (a) influence of scarification treatments; (b) seedling emergence during 5 years after dry heat scarification of freshly matured seeds, and evaluating intrapopulation variation; (c) seedling emergence after dry heat scarification of seeds rescued from soil; and (d) ability to form persistent soil seed banks. Key results Dry heat scarification of freshly matured seeds only resulted in 22.5% germination. However, exposure to pre-sowing thermal shock stimulated seedling emergence during the first few years post-planting, with high intrapopulation variation. In seeds recovered from soil, thermal shock before reseeding increased the seedling emergence rate. Conclusions and implications Our results show that, to avoid incomplete interpretation, studies of thermal treatment on the breaking of physical seed dormancy should allow the seeds sufficient time to exhibit the complete effects of high temperature treatment, thereby preventing underestimation.

Genetic Diversity and Structure of Persian Walnut (Juglans regia L.) in Pakistan: Implications for Conservation.

Persian (Common) walnut (Juglans regia L.) is a famous fruit tree species valued for its nutritious nuts and high-quality wood. Although walnut is widely distributed and plays an important role in the economy and culture of Pakistan, the genetic diversity and structure of its populations in the country remains poorly understood. Therefore, using 31 nuclear microsatellites, we assessed the genetic diversity and population structure of 12 walnut populations sampled across Pakistan. We also implemented the geostatistical IDW technique in ArcGIS to reveal “hotspots” of genetic diversity. Generally, the studied populations registered relatively low indices of genetic diversity (NA = 3.839, HO = 0.558, UHE = 0.580), and eight populations had positive inbreeding coefficient (FIS) values. Low among-population differentiation was indicated by AMOVA, pairwise FST and DC. STRUCTURE, PCoA and neighbor joining (NJ) analysis revealed a general lack of clear clustering in the populations except that one population in Upper Dir was clearly genetically distinct from the rest. Furthermore, the Mantel test showed no correlation between the geographic and genetic distance (r = 0.14, p = 0.22), while barrier analysis suggested three statistically significant genetic barriers. Finally, the spatial interpolation results indicated that populations in Ziarat, Kashmir, Dir, Swat, Chitral, and upper Dir had high intrapopulation genetic diversity, suggesting the need to conserve populations in those areas. The results from this study will be important for future breeding improvement and conservation of walnuts in Pakistan.

Seed mass, dormancy and germinability variation among maternal plants of four Arabian halophytes

AbstractCoastal desert vegetation of the Arabian Peninsula is almost entirely dominated by halophytes. Natural populations provide a genetic resource for ecological remediation and may also have direct economic value. High intrapopulation variation of seed traits is presumed to increase population persistence in the unpredictable climatic conditions of this hyper-arid desert. We investigated whether intrapopulation variation of seed mass, dormancy and germinability of four species was attributable to maternal individuals. Arthrocnemum macrostachyum, Halothamnus iraquensis, Haloxylon salicornicum and Seidlitzia rosmarinus are commonly distributed Arabian halophytes with differing seed weight variation. All species exhibited a higher germination when exposed daily to 12 h light, compared to seeds in darkness. A higher germination was correlated with a shorter germination time. For H. iraquensis and S. rosmarinus, a shorter germination time was negatively correlated with germination synchrony. H. salicornicum showed the highest intrapopulation variation of seed traits, followed by A. macrostachyum, S. rosmarinus and H. iraqensis. We found that individuals within populations of all the studied species showed variability in germination but the extent of variation was species-specific. The variation in seed mass and germination among the individuals of the studied species may facilitate a temporal distribution of germination, which may reduce the risk of seed bank exhaustion. The results of this study could assist conservation and management by improving the efficiency of seed collection from wild populations of these species.

Do we have infraspecific taxa of Salvia macrosiphon Boiss. (Lamiaceae) in Iran?

Salvia macrosiphon is an aromatic perennial species of Lamiaceae family that grows naturally in different parts of Iran. This herb is widely used in folk and modern medicine. Although in Flora Iranica and Flora of Iran, no infraspecific taxonomic rank has been detected for S. macrosiphon, some infraspecific taxonomic ranks have been reported. In the current study, we evaluated the genetic diversity and structure of 11 populations of this species to detect inter and intrapopulation genetic diversity and to survey the possibility of infraspecific taxonomic ranks in this species. We utilized the modified C-TAB protocol for DNA extraction and amplified the genomes using several SCoT molecular markers. We calculated of genetic diversity and polymorphism parameters using GenAlex 6.4, Geno-Dive ver.2, PopGene, PopART and Structure 2.3.4. The parameters of genetic polymorphism differed between the populations. Moreover, a low rate of gene flow supported a moderate level of population's genetic diversity and differentiation. According to haplotypes network (TCS) analysis, a high level of genetic mutation has occurred among the individuals of some populations leading to high intrapopulation diversity. On the basis of structure analysis and Nei's genetic distance, the examined populations were classified into four genotypes. The clustering pattern of the populations in each group was not related to geographical distance or phytogeography. It seems that the wide geographic distribution, a small gene flow rate and the occurrence of a high level of genetic mutation lead to infraspecific genetic differentiation in the species and we suppose some infraspecific ranks exist for it.

Nesting of fieldfare <i>Turdus pilaris</i> (Linnaeus, 1758) (Aves, Passeriformes) in floodplain habitats of the Abakan River basin (South Minusinsk basin)

This paper presents the results of long-term observations of the fieldfare breeding biology in the South Minusinsk basin. The observations were carried out at two sites in floodplain habitats of the Abakan River basin. Comparisons were made with the indicators of the breeding biology of the species in the North-Minusinsk basin, which were published. The fieldfare builds nests on all kinds of woody plants that are found in the floodplain. The time of Turdus pilaris reproduction beginning in the steppe basin varied from the 20th of April to the first five days of May. Differences in the breeding periods of fieldfare in populations from different altitude-belt complexes (steppe and forest-steppe) were revealed. There is a difference in the height of nests on woody plants, depending on the architectonics of the crown, and in areas with varying degrees of concern. Dimensional characteristics of nests and eggs are given. High intrapopulation variability of egg size was noted. The coefficient of variation for the larger and for the smaller diameter was 1113%. The full clutch consisted of 46 eggs. The average clutch size was 4,95,2 eggs. Differences in the average size of the masonry on different territories were not revealed. The success rate of nesting in 2021 was high (5072%).

Variability of some broomrape populations from China. Genotyping and determination of genetic polymorphism (II)

Genetic diversity within a population is reflected by variations in genetic material among individuals and can manifest at the phenotypic level through new characters or traits. The emergence of a large number of O. cumana races in a short period of time demonstrates that there are higher genetic variability in populations and a high ability to adapt in the face of environmental conditions. The aim of the research presented in this article was to study the intraand interpopulation genetic diversity and genetic relationships between individuals of three populations of O. cumana from different geographical regions of the People’s Republic of China based on molecular markers (ISSR and SSR). The high intrapopulation genetic variability calculated on the basis of the allelic diversity parameters and specific genetic diversity coefficients was revealed by SSR markers while as for the ISSR primers a high degree of genetic variations was found at the interpopulation level. UPGMA clustering and principal component analysis performed according to both sets of molecular markers allowed to devide all genotypes into 5 major groups for the degree of dissimilarity and level of aggression. This study is of interest in understanding the population genetic structure of the parasitic species of O. cumana from China and could contribute to the development of pathogen control durable strategies and effective sunflower breeding programs to broomrape resistance.

Spatial pattern of genetic diversity in field populations of Fusarium incarnatum-equiseti species complex.

Fusarium is associated with a number of wilt, blight, scab, and rot diseases in a range of economically important staple food crops worldwide. An assessment of the genetic structure and population stratification of Fusarium incarnatum‐equiseti species complex (FIESC) pathogen populations is important to understand the evolutionary potential of such populations in adapting to environmental change. Based on intersimple sequence repeat polymerase chain reaction (ISSR‐PCR), it was found that the pathogen population was structured into three genetic clusters for which genetic differentiation was higher within than among populations. There was high intrapopulation genetic diversity for population 1 (94.63%) which consisted largely of isolates collected from North Trinidad. Populations 2 and 3 had a low level of admixture among the populations based on overall population differentiation. Population 1 accounted for the highest amount of genetic variation (95.82%) followed by populations 2 and 3. Population stratification was reflected in the dendrogram topology, which consisted of three main genetic clusters and which coincided with the outcome of Bayesian and PCoA analyses. The populations were isolated by distance, and Voronoi tessellations indicated physical or structural barriers to gene flow which contributed to restricted admixture between two of three populations. These findings suggest a high evolutionary potential for this FIESC pathogen population, the implications of which directly affect disease management strategies.

Genetic Diversity and Mating Type Distribution of Pseudocercospora fijiensis on Banana in Uganda and Tanzania.

Black Sigatoka, caused by Pseudocercospora fijiensis, is a major foliar disease of banana and plantain worldwide. There are few available data regarding the genetic diversity and population structure of the pathogen in East Africa, which are needed to design effective and durable disease management strategies. We genotyped 319 single-spore isolates of P. fijiensis collected from seven regions in Uganda and Tanzania and five isolates from Nigeria using 16 simple sequence repeat markers and mating type-specific primers. Isolates from each country and region within the country were treated as populations and subpopulations, respectively. A total of 296 multilocus genotypes (MLGs) were recovered, representing a clonal fraction of 7%. Subpopulations had a moderate level of genetic diversity (Hexp = 0.12 to 0.31; mean, 0.29). Mating type distribution did not deviate from equilibrium (MAT1-1: MAT1-2, 1:1 ratio) in Uganda; however, in Tanzania the mating types were not in equilibrium (4:1 ratio). The index of association tests (IA and r̄d) showed that all populations were at linkage equilibrium (P > 0.05), thus supporting the hypothesis of random association of alleles. These findings are consistent with a pathogen that reproduces both clonally and sexually. Low and insignificant levels of population differentiation were detected, with 90% of the variation occurring among isolates within subpopulations. The high intrapopulation variation has implications in breeding for resistance to P. fijiensis because isolates differing in aggressiveness and virulence are likely to exist over small spatial scales. Diverse isolates will be required for resistance screening to ensure selection of banana cultivars with durable resistance to Sigatoka in East Africa.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

The Evolutionary Success of the Marine Bacterium SAR11 Analyzed through a Metagenomic Perspective.

The SAR11 clade of Alphaproteobacteria is the most abundant group of planktonic cells in the near-surface epipelagic waters of the ocean, but the mechanisms underlying its exceptional success have not been fully elucidated. Here, we applied a metagenomic approach to explore microdiversity patterns by measuring the accumulation of synonymous and nonsynonymous mutations as well as homologous recombination in populations of SAR11 from different aquatic habitats (marine epipelagic, bathypelagic, and surface freshwater). The patterns of mutation accumulation and recombination were compared to those of other groups of representative marine microbes with multiple ecological strategies that share the same marine habitat, namely, Cyanobacteria (Prochlorococcus and Synechococcus), Archaea ("Candidatus Nitrosopelagicus" and Marine Group II Thalassoarchaea), and some heterotrophic marine bacteria (Alteromonas and Erythrobacter). SAR11 populations showed widespread recombination among distantly related members, preventing divergence leading to a genetically stable population. Moreover, their high intrapopulation sequence diversity with an enrichment in synonymous replacements supports the idea of a very ancient divergence and the coexistence of multiple different clones. However, other microbes analyzed seem to follow different evolutionary dynamics where processes of diversification driven by geographic and ecological instability produce a higher number of nonsynonymous replacements and lower intrapopulation sequence diversity. Together, these data shed light on some of the evolutionary and ecological processes that lead to the large genomic diversity in SAR11. Furthermore, this approach can be applied to other similar microbes that are difficult to culture in the laboratory, but abundant in nature, to investigate the underlying dynamics of their genomic evolution.IMPORTANCE As the most abundant bacteria in oceans, the Pelagibacterales order (here SAR11) plays an important role in the global carbon cycle, but the study of the evolutionary forces driving its evolution has lagged considerably due to the inherent difficulty of obtaining pure cultures. Multiple evolutionary models have been proposed to explain the diversification of distinct lineages within a population; however, the identification of many of these patterns in natural populations remains mostly enigmatic. We have used a metagenomic approach to explore microdiversity patterns in their natural habitats. Comparison with a collection of bacterial and archaeal groups from the same environments shows that SAR11 populations have a different evolutionary regime, where multiple genotypes coexist within the same population and remain stable over time. Widespread homologous recombination could be one of the main driving factors of this homogenization.

Diagnostics of Polymerus Hahn (Heteroptera, Miridae) Species Group Including Agricultural Pests in the East European Forest-Steppe, Based on Morphological and Molecular Characters

The paper presents an improved key to the co-occurring species of Polymerus Hahn, 1831 (Heteroptera, Miridae) based on morphological characters and our new data on the differences between the COI gene DNA sequences of these species. These characters, together with the data stored in the NCBI GenBank, provide the means for accurate and rapid identification of adults and nymphs of Polymerus unciniger Gapon, 2014, P. unifasciatus (Fabricius, 1794), P. cognatus (Fieber, 1858), P. vulneratus (Panzer, 1806), and P. brevicornis (Reuter, 1879). The subgenera Poeciloscytus Fieber, 1858 and Pachycentrum Gapon, 2014 differ considerably in morphological and molecular genetic characteristics. A PCR-RFLP method has been developed for rapid identification of the pest species P. vulneratus. The morphological characters of P. unifasciatus and the COI gene sequences of the forms earlier registered in GenBank as P. unifasciatus and P. microphthalmus (Wagner, 1951) reveal high intrapopulation variability. Polymerus microphthalmus may be a submacropterous form of P. unifasciatus with shortened hemelytra and smaller eyes, while the macropterous form of the latter species is characterized by larger eyes.

Within‐and among‐population differentiation of Aphaniops hormuzensis from ecologically diverse environments (Cyprinodontiformes; Aphaniidae)

AbstractThe active geology and ecological diversity in the Persian Gulf drainages create a rich source of biodiversity for the tooth‐carp fishes from which evolutionary processes can be studied. Here, we explored morphological differentiation in tooth‐carp Aphaniops hormuzensis from three ecologically diverse habitats (Khurgu sulphuric spring, Shur high‐salinity river and the urban canal) in the Hormuz riverine system, southern Iran. The evidence of sexual dimorphism was found in fish and otolith traits mainly in the Khurgu spring. The extreme conditions of the Khurgu spring could lead to the microhabitat segregation by fish individuals with different ages and spatial sexual segregation, and caused high intrapopulation differentiation in this site. However, the most diverged population belonged to the urban canal, which had more elongated pre‐ and post‐dorsal lengths, as well as a deep otolith. In sum, the observed phenotypic variations in A. hormuzensis are mainly influenced by sex‐dependent factors such as sexual dimorphism and the specific ecological condition of the Khurgu sulphuric spring (extreme sulphur‐rich habitat) and the urban canal (high food availability and hybridization event). This study provides the basic opportunity to explore the relative roles of ecological divergence and habitat differences in the morphological differentiation of A. hormuzensis.

Multi-level patterns of genetic structure and isolation by distance in the widespread plant Mimulus guttatus.

An understanding of genetic structure is essential for answering many questions in population genetics. However, complex population dynamics and scale-dependent processes can make it difficult to detect if there are distinct genetic clusters present in natural populations. Inferring discrete population structure is particularly challenging in the presence of continuous genetic variation such as isolation by distance. Here, we use the plant species Mimulus guttatus as a case study for understanding genetic structure at three spatial scales. We use reduced-representation sequencing and marker-based genotyping to understand dispersal dynamics and to characterise genetic structure. Our results provide insight into the spatial scale of genetic structure in a widespread plant species, and demonstrate how dispersal affects spatial genetic variation at the local, regional, and range-wide scale. At a fine-spatial scale, we show dispersal is rampant with little evidence of spatial genetic structure within populations. At a regional-scale, we show continuous differentiation driven by isolation by distance over hundreds of kilometres, with broad geographic genetic clusters that span major barriers to dispersal. Across Western North America, we observe geographic genetic structure and the genetic signature of multiple postglacial recolonisation events, with historical gene flow linking isolated populations. Our genetic analyses show M. guttatus is highly dispersive and maintains large metapopulations with high intrapopulation variation. This high diversity and dispersal confounds the inference of genetic structure, with multi-level sampling and spatially-explicit analyses required to understand population history.