Species Complex Research Articles

The genome of a giant clam zooxanthella (Cladocopium infistulum) offers few clues to adaptation as an extracellular symbiont with high thermotolerance

BackgroundCladocopium infistulum (Symbiodiniaceae) is a dinoflagellate specialized to live in symbiosis with western Pacific giant clams (Tridacnidae). Unlike coral-associated symbionts, which reside within the host cells, C. infistulum inhabits the extracellular spaces of the clam’s digestive diverticula. It is phylogenetically basal to a large species complex of stress-tolerant Cladocopium, many of which are associated with important reef-building corals in the genus Porites. This close phylogenetic relationship may explain why C. infistulum exhibits high thermotolerance relative to other tridacnid symbionts. Moreover, past analyses of microsatellite loci indicated that Cladocopium underwent whole-genome duplication prior to the adaptive radiations that led to its present diversity.ResultsA draft genome assembly of C. infistulum was produced using long- and short-read sequences to explore the genomic basis for adaptations underlying thermotolerance and extracellular symbiosis among dinoflagellates and to look for evidence of genome duplication. Comparison to three other Cladocopium genomes revealed no obvious over-representation of gene groups or families whose functions would be important for maintaining C. infistulum’s unique physiological and ecological properties. Preliminary analyses support the existence of partial or whole-genome duplication among Cladocopium, but additional high-quality genomes are required to substantiate these findings.ConclusionAlthough this investigation of Cladocopium infistulum revealed no patterns diagnostic of heat tolerance or extracellular symbiosis in terms of overrepresentation of gene functions or genes under selection, it provided a valuable genomic resource for comparative analyses. It also indicates that ecological divergence among Cladocopium species, and potentially among other dinoflagellates, is partially governed by mechanisms other than gene content. Thus, additional high-quality, multiomic data are needed to explore the molecular basis of key phenotypes among symbiotic microalgae.

Genital coupling and copulatory wounding in the Drosophila rufa species complex: comparison with the D. auraria species complex (Diptera: Drosophilidae)

Abstract In sexually reproducing animals, genital morphology is usually divergent among closely related species, which can lead to a mismatch of genital coupling (i.e. mechanical isolation). The montium species group of the subgenus Sophophora is the largest clade in Drosophila and is a useful model in which to study the evolution of genital morphology. This group includes a pair of sister clades, i.e. the Drosophila auraria and Drosophila rufa species complexes. The former includes four species with overlapping distributions, and the latter consists of five species that are almost allopatric. The previous study on the D. auraria complex suggested genital co-evolution between sexes (female structures accepting for or protecting from male structures). To test the generality, we analysed the D. rufa complex and three outgroup species. In the D. rufa complex, we detected genital structures corresponding between sexes, and copulatory wounds with species-specific positions. Given that approximately the same number of evolutionary changes in the genital traits were detected in both sexes of the two clades, we conclude that selection pressure to avoid interspecific mating (reproductive character displacement) is not a prerequisite for rapid genital co-evolution.

Phylogenomic insights into Neotropical Magnolia relationships

Despite extensive research into the phylogenetic relationships of the genus Magnolia, Neotropical taxa have been neglected. This is partly because their numbers have recently doubled and now account for almost half of the global richness. Therefore, by sampling one-third of all Neotropical taxa their relationships were studied using morphological, nuclear, and plastome data. Two major clades were identified: Clade I, comprising Magnolia sect. Talauma, Magnolia sect. Splendentes from the Neotropics, and the Asian Magnolia sect. Gwillimia; while Clade II included the Neotropical clades Magnolia sect. Macrophylla and Magnolia sect. Magnolia, along with the remaining non-Neotropical sections. Within Clade I, Magnolia sect. Talauma was geographically divided into a northern subclade grouping Mexican and Central American taxa, and a southern subclade comprising South American and Caribbean taxa. Magnolia sect. Splendentes was also dichotomously divided, corresponding to the former Magnolia sect. Talauma subsect. Cubenses and Magnolia sect. Talauma subsect. Dugandiodendron. In Clade II, the relationships within Magnolia sect. Macrophylla and Magnolia sect. Magnolia were unclear, suggesting a species complex in all Magnolia sect. Macrophylla taxa. In total, 25 morphological traits were assessed, and ancestral state reconstructions were carried out. Only the joined clustering of mature follicles was a synapomorphy for the southern subclade of Magnolia sect. Talauma. In conclusion, this highlights the need to re-assess the taxonomic delimitation of certain groups, to update the infrageneric classification of Neotropical clades and to explore morphological traits to support them.

Characterization and Fungicide Sensitivity of Colletotrichum spp. from Capsicum peppers in South Korea.

Capsicum peppers, peppers from plants of the genus Capsicum (family Solanaceae), are widely cultivated in South Korea, where annual production was 92,756 tons in 2021, 54.4% higher than that of the previous year. Occurring throughout the production cycle, anthracnose is a major disease limiting commercial Capsicum pepper production worldwide, including in South Korea. This study investigates the diversity and pathogenicity of Colletotrichum species responsible for Capsicum pepper anthracnose in Gyeongbuk, South Korea, focusing on disease incidence and symptomatology in the field and the identification, morphological characteristics, pathogenicity, and fungicide sensitivity of the causative species. Disease incidence ranged from 30 to 50%, with samples categorized into three distinct symptom types, aiding accurate field diagnosis. Phylogenetic analysis classified 41 isolates into six species in the acutatum, gloeosporioides, and truncatum species complexes, revealing significant genetic diversity. Morphological characterization supported these identifications, providing a comprehensive profiling. Pathogenicity tests confirmed that all identified species induced typical anthracnose lesions, with lesion size variations suggesting differential aggressiveness. Temperature significantly influenced mycelial growth, with optimal growth between 20 and 26°C, and C. truncatum demonstrating high-temperature tolerance.In vitro fungicide sensitivity tests showed variable responses, with tebuconazole being generally effective. These findings underscore the need for species-specific fungicide recommendations and highlight the importance of continuous monitoring of Colletotrichum species. Future research should explore the molecular mechanisms of pathogenicity, host specificity, and fungicide resistance, integrating these findings with breeding programs to develop resistant pepper varieties. This study provides critical insights for effective anthracnose management in pepper cultivation and future research directions.

Effect of temperature on in vitro germination and growth of Colletotrichum fioriniae, a new emerging pathogen of olive fruits.

Olive anthracnose induced by different Colletotrichum species causes dramatic losses of fruit yield and oil quality. The increasing incidence of Colletotrichum fioriniae (Colletotrichum acutatum species complex) as causal agent of olive anthracnose in Italy, is endorsing new studies on its biology, ecology, and environmental factors such as temperature. Five isolates from different sampling sites in Lazio region (Central Italy) were studied under controlled laboratory conditions aiming to better understand the differences of thermal development among the isolates and to lay the foundations of a future mathematical model able to describe the key aspects of the pathogen's life cycle. The mycelial growth rate and the conidial germination rate were assessed at seven different constant temperatures (5, 10, 15, 20, 25, 30, and 35°C) and fixed relative humidity (100% RH). The obtained dataset was analysed to estimate the parameters of mathematical functions that connect the mycelial growth rate and the spore germination with the environmental temperature. The parameters set provided as the result of this study constitute a key step forward in the biological knowledge of the species and the basis for future formulations of mathematical models that might be the core of decision support systems in an integrated pest management framework.

Freezing stress tolerance of benthic freshwater diatoms from the genus Pinnularia: Comparison of strains from polar, alpine, and temperate habitats.

Diatoms are among the most important primary producers in alpine and polar freshwaters. Although temperate diatoms are sensitive to freezing, polar diatoms often exhibit more resistance. This is particularly true for members of the (predominantly terrestrial) Pinnularia borealis species complex. However, it remains unclear to what extent this resistance applies to other representatives of the genus. Here, we compare the freezing-stress tolerance of 11 freshwater, benthic strains representing different species of Pinnularia (including Caloneis) from polar, alpine, and temperate habitats. As vegetative cells, strains were exposed to freezing temperatures of -4, -10, -20, -40, -80, and -196°C. Survival was assessed by light microscopy and photosynthetic measurements. We observed vegetative cells to be sensitive to low freezing temperatures; only "mild" freezing was survived by all tested strains, and most tested strains did not survive treatments ≤-10°C. However, individual strain sensitivities appeared related to their original habitats. For example, polar and alpine strains better withstood "mild" and "moderate" freezing (-4 and -10°C, respectively); although temperate strains were significantly affected by the "mild" freezing treatment, polar and alpine strains were not. The -10°C treatment was survived exclusively by polar strains, and only P. catenaborealis survived all treatments. Interestingly, this species exhibited the lowest survival in the -10°C treatment, potentially implying some metabolic activity even at freezing temperatures. Thus, despite more extensive sampling throughout the genus and finer temperature scaling compared to previous studies, the remarkable freezing-stress tolerance of the P. borealis species complex remains unique within the genus.

Aspergillus aureoterreus, A. pseudonomiae, A. siamensis, and A. flocculosus-ochraceopetaliformis as Four New Pathogens of Eye Infection in DNA Barcoding Markers

Background: The use of a morphological method to determine Aspergillus species in routine laboratory investigation has always been challenged with low sensitivity and low specificity. Time-consuming specimen preparation and insufficient expertise are the crucial reasons. DNA barcoding markers have been introduced for identification as another gold standard method. Objective: To investigate DNA barcoding markers in identifying Aspergillus strains isolated from patients with eye infection. Methods: This study extracted 12 DNA samples of 12 Aspergillus strains. DNA barcoding genes, i.e., ITS, betatubulin (BT2), calmodulin (CAL), and actin (ACT) genes, were amplified and sequenced by polymerase chain reaction and Sanger's sequencing methods. All gene sequences were compared to those of the type or reference species collected from public databases. The species were identified with phylogenetic analyses in free applications from public websites. Results: ITS, BT2 and CAL, and ACT identified 5, 6, and 3 species and 3, 2, and 1 species complex of Aspergillus, respectively. DNA barcoding with multi-locus sequence typing revealed four new pathogens of human eye infection, including A. aureoterreus, A. pseudonomiae, A. siamensis, and A. flocculosus-ochraceopetaliformis. Conclusion: The DNA barcoding markers identified Aspergillus species with better specificity than the conventional method. The markers and techniques need to be used as tools for routine Aspergillus identification.

Assessment of nine markers for phylogeny, species and haplotype identification of Kappaphycus species and Eucheuma denticulatum (Solieriaceae, Rhodophyta)

ABSTRACT Molecular studies have contributed to the taxonomy of carrageenan-producing Kappaphycus spp. and Eucheuma denticulatum. However, unresolved species complexes and the lack of standardization in the use of genetic markers impede the identification of specimens and the delineation of a robust taxonomic framework. Here, nine molecular markers (cox1, cox2–3 spacer, cox2, cox3, COB, ITS, psbA, UPA and rbcL) were used to generate a multilocus phylogeny for 113 fresh eucheumatoid samples and four herbarium specimens. Analyses of species delineation and genetic distances confirmed the monophyly of currently accepted taxa. These analyses suggest that clades previously reported as K. striatus KS1 and KS2 are conspecific, and that E. denticulatum EDA ‘spinosum’ and EDB ‘endong/cacing’ are also conspecific. The results also unveiled possible new taxa from Hawaii and Indonesia. Each molecular marker and combinations thereof were assessed with regard to species identification, ease of amplification and sequencing, and haplotype characterization. All genetic markers recorded at least 94% success in the amplification and sequencing of fresh specimens, with cox1 being the most phylogenetically informative. Automatic partitioning, phylogenetic and tree-based assessments showed cox1, cox2–3 spacer, cox2 and rbcL were able to correctly identify species while cox1+ rbcL, COB+rbcL, cox2+ rbcL or cox1+ COB+rbcL trees best represented the phylogeny with consistently high nodal support. Among individual markers, cox1 identified the greatest number of haplotypes, while UPA, partial rbcL (750 bp), ITS, cox3 and cox2–3 spacer were able to retrieve information from herbarium specimens of 12–16 years of age. These molecular results provide a basis for a database essential for the taxonomic framework, cultivar development and germplasm conservation of eucheumatoids.

Hidden gems: Scattered knowledge hampered freshwater jellyfish research over the past one-and-a-half centuries.

Freshwater jellyfish (= limnic medusa-budding hydrozoans, FWJ) are a small group of cnidarians found on all continents except Antarctica in temperate to tropical latitudes. Members of this group belong primarily to three genera: Astrohydra, Craspedacusta, and Limnocnida. While Astrohydra and Limnocnida are typically restricted to the islands of Japan, Africa, and the Indian subcontinent, one species or potential species complex, Craspedacusta sowerbii, became globally invasive. Despite research going back about one-and-a-half centuries, little is known about their phylogeny and ecology compared to marine jellyfish. Recent species distribution modelling, however, showed that by 2050, C. sowerbii will potentially extend their distribution ranges due to global warming to high-latitude ecosystems and be present (medusa stage) for an extended time in the seasonal limnic production cycle. An increase in their relative ecological importance with temporal and spatial spreading is hypothesised. Only recently, it has been shown that the trophic roles of polyps and medusae and their prey overlap with other ecosystem members. In addition, medusa behaviour may cause trophic cascades and alter vertical nutrient distributions. However, polyps and other benthic life cycle stages are understudied. In globally, changing freshwater ecosystems that may become more accommodating for FWJ, an improved understanding of their population biology and ecosystem ecology is urgently needed. In this integrative review, we, therefore, explore reasons for the hampered historical research progress, contrast developments with those of marine cnidarians, compile and publish alongside an extensive and unprecedented literature database, and formulate avenues for future directions in FWJ research.

Epidemiological survey of two morphotypes of Demodex folliculorum (Prostigmata: Demodicidade) in young people from southern Spain

Different morphotypes of Demodex from humans have been described. Among them, molecular studies have made it possible to discern between the Demodex folliculorum and Demodex brevis. Further studies showed two morphotypes of D. folliculorum harboured two different habits (human skin and human eyelashes), both of them with finger-shaped terminal opisthosoma difficult to differentiate and that can be assigned to D. folliculorum,Thus, a complete morphometric study of the species, which in this study are referred to as Demodex folliculorum species complex, was carried out. From this morphometric and meristic study two distinct morphological forms (short and long) could be identified within the Demodex folliculorum species complex. These forms differ significantly in four out of the six biometric parameters we analysed: gnathosomal length and width, podosomal width, and opisthosomal length. Moreover, a comprehensive survey of the two morphotypes from different habitats (skin and eyelashes), was carried out in young people of Southern Spain. Therefore, an analysis of 104 asymptomatic students, which were contact lens wearers, and the presence of D. folliculorum was carried out. A statistical analysis based on Bayesian zero inflated Poisson GLM has been applied to our sample data. For the age group considered (18–24 years old), the overall D. folliculorum prevalence for skin face or eye infections (at least one of them) was 19.31 % (51 people), with a statistically significant higher prevalence in males men. Furthermore, there is a slight statistical correlation between the presence of Demodex in silicone hydrogel soft contact lens wearers. This study confirms: i) the existence of two morphotypes of D. folliculorum that appear segregated due to the parasitization microhabitats,ii) a higher prevalence of mites in men than in women, iii) the existence of a high number of statistically supported double infections (skin-eyelashes). It also provides epidemiological data on the prevalence of long and short forms of D. folliculorum in a healthy young population.

Molecular Markers for Analyses of Genetic Diversity within the Anastrepha fraterculus Complex with Emphasis on Argentine Populations.

The South American fruit fly Anastrepha fraterculus (Wiedmann) has a vast range extending from northern Mexico, through Central America, to South America where it is an extremely polyphagous pest of wild and cultivated fruits. It is a complex of cryptic species currently composed of eight recognised morphotypes: "Mexican", "Venezuelan", "Andean", "Peruvian", "Ecuadorian", and the three Brazilian morphotypes "Brazilian-1", "Brazilian-2", and "Brazilian-3". Molecular markers that can identify the member species of the complex are crucial for the implementation of effective pest control measures, such as the sterile insect technique. The object of this study was to evaluate the use of the internal transcribed spacer 2 (ITS2) sequence for discriminating several members of the A. fraterculus cryptic species complex (Mexican, Peruvian, and Brazilian-1) and a related species, Anastrepha schultzi Blanchard. The analysis highlighted significant genetic differentiation between the evaluated morphotypes, allowed their discrimination within the A. fraterculus cryptic species complex, and provided new insights into their genetic relationships. The ITS2 marker provides a basis for the development of taxonomic keys for the discrimination of the cryptic taxa within the A. fraterculus cryptic species complex. ITS2 also represents an important marker for the poorly studied species A. schultzi.

Colletotrichum species associated with anthracnose disease on mango (Mangifera indica L.) cv. Azúcar in Colombia

The role of some Colletotrichum species is uncertain in crops of economic importance for Colombia such as mango (Mangifera indica L.) cv. Azúcar. Eight Colletotrichum isolates from asymptomatic plant tissues were characterized by their pathogenicity on fruits and identified by phylogenetic analysis of the sequences of the ITS, GADPH, Tub2, CHs-1 and Act genomic regions. Colletotrichum asianum, C. gloeosporioides and C. tropicale of the C. gloeosporioides species complex and C. karstii of the C. boninense species complex were identified. The highest virulence was observed for isolates of C. asianum, that was the most prevalent species, and for C. tropicale, that showed high and intermediate virulence levels, indicating diversity in pathogenicity within the same species. The isolate of C. karstii, which displayed intermediate virulence, is the first report on mango in Colombia. Colletotrichum gloeosporioides presented intermediate virulence and was isolated at a low frequency in the present research. The mycelial growth rate did not show differences between species and ranged between 6.1 and 8.3 mm per day. Colletotrichum asianum recorded higher values of conidia germination and appressoria formation than other species, at 77% and 79%, respectively (p < 0.001). The shape and size of conidia did not vary between species. Appressoria exhibited different shapes between isolates and the largest average diameter was for C. karstii with 7.6 µm (p < 0.001). There was a diversity of Colletotrichum species associated with mango cv. Azúcar in Colombia, with differential virulence among isolates of the same species.

The Genome Architecture of the Copepod Eurytemora carolleeae, the Highly Invasive Atlantic Clade of the E. affinis Species Complex.

Copepods are among the most abundant organisms on the planet and play critical functions in aquatic ecosystems. Among copepods, populations of the Eurytemora affinis species complex are numerically dominant in many coastal habitats and are food sources for major fisheries. Intriguingly, certain populations possess the unusual capacity to invade novel salinities on rapid time scales. Despite their ecological importance, high-quality genomic resources have been absent for calanoid copepods, limiting our ability to comprehensively dissect the genome architecture underlying the highly invasive and adaptive capacity of certain populations. Here, we presented the first chromosome-level genome of a calanoid copepod, from the Atlantic clade (Eurytemora carolleeae) of the E. affinis species complex. This genome was assembled using high-coverage long-read and high-throughput chromosome conformation capture sequences of an inbred line, generated through 30 generations of full-sib mating. This genome, consisting of 529.3 megabase (Mb) (contig N50 = 4.2 Mb, scaffold N50 = 140.6 Mb), was anchored onto four chromosomes. Genome annotation predicted 20,262 protein-coding genes, of which ion transporter gene families were substantially expanded based on comparative analyses of 12 additional arthropod genomes. Also, we found genome-wide signatures of historical gene body methylation of the ion transporter genes and the significant clustering of these genes on each chromosome. This genome represents one of the most contiguous copepod genomes to date and among the highest quality marine invertebrate genomes. As such, this genome provides an invaluable resource to help yield fundamental insights into the ability of this copepod to adapt to rapidly changing environments.

An integrative phylogeography for inferring cryptic speciation in the Alpheus lottini species complex, an important coral mutualist

An integrative phylogeography for inferring cryptic speciation in the Alpheus lottini species complex, an important coral mutualist

Pathogenicity and Metabolomic Characterization of Fusarium graminearum and Fusarium poae Challenge in Barley under Controlled Conditions.

Barley is the third most important cereal crop in terms of production in Canada, and Fusarium head blight (FHB) is one of the main fungal diseases of barley. FHB is caused by a species complex of Fusaria, of which Fusarium graminearum Schwabe is the main causal species of FHB epidemics in Canada. Field surveys show that two or more Fusarium species often co-exist within the same field or grain sample, and F. poae is reported as another important species in barley. This study aimed to determine the pathogenicity of F. graminearum, F. poae, and a co-inoculation of both species causing FHB in barley. Two susceptible barley cultivars were spray-inoculated at 10 to 14 days after heading. Phenotypic disease severity was rated on a scale of 0-9 at 4, 7, 14, 21, and 28 days after inoculation. There was a significant difference in FHB severity between F. graminearum and F. poae, where infection with F. graminearum produced more severe disease ratings. F. poae generated lower disease ratings and was not statistically different from the control. When heads were co-inoculated with both Fusarium species, the resulting FHB severity was unchanged relative to heads inoculated with F. graminearum only. The ratio of F. graminearum to F. poae genomic DNA was also no different than when heads were inoculated with F. graminearum alone, as quantified with ddPCR using markers specific to each species. The metabolomic analysis of sample extracts showed that F. graminearum-associated metabolites dominated the mycotoxin profile of co-inoculated samples, which corroborated our other findings where F. graminearum appeared to outcompete F. poae in barley. No significant effect on visual FHB disease ratings or fungal DNA detection was observed between the cultivars tested. However, there were some metabolome differences between cultivars in response to the challenge by both F. graminearum and F. poae.

Identification and molecular detection of the pathogen of Phalaenopsis leaf yellowing through genome analysis.

Moth orchids (Phalaenopsis spp.) are globally popular ornamental flowers. However, effective management strategies for Phalaenopsis leaf yellowing remain elusive, making the disease a challenging obstacle affecting moth orchids at various growth stages. This disease manifests as collar rot, leaf yellowing, leaf abscission, and eventually, plant death. The lack of effective management strategies is likely attributed to a limited understanding of the disease pathogenesis and pathogen dissemination pathways. Fusarium phalaenopsidis sp. nov. was established in this study to stabilize the classification status of Phalaenopsis leaf yellowing pathogens using molecular and morphological features. The genome of the holotype strain was sequenced and assembled, revealing its genome structures. Analyses of virulence-related elements, including transposon elements, secondary metabolite biosynthetic gene clusters, effectors, and secreted carbohydrate-active enzymes, shed light on the potential roles of three fast core chromosomes in virulence. Two species-specific primers were designed based on unique gene sequences of two virulence-related proteins through comparative genomics and BLAST screening. The specificity of these primers was validated using isolates of F. phalaenopsidis, non-target species in the Fusarium solani species complex, other Fusarium species complexes, and saprophytic fungi. These results are intended to accelerate the identification of the pathogens, facilitate the study of disease pathogenesis, and pave the way for elucidating pathogen dissemination pathways. Ultimately, they aim to contribute to the formulation of effective control strategies against Phalaenopsis leaf yellowing.

Investigation of the distribution patterns in moinids (Crustacea: Cladocera: Moinidae) forming ephippia with two resting eggs

During last two decades, morphological and genetic studies of the microcrustaceans from the family Moinidae Goulden, 1968 (Crustacea: Branchiopoda: Cladocera) were intensified. However, species diversity within this family remains underestimated. It refers to both subtropical and tropical areas of different continents that have traditionally been less studied compared with Central Europe and some other Palaearctic regions. In addition to this, only a restricted set of morphological characteristics is used for the discrimination of species within the genus Moina Baird, 1850. Most common moinid taxa are considered species complexes rather than single species, making any biogeographic reconstruction difficult. Here, we present an investigation of distribution patterns in moinids that form ephippia with two resting eggs based on both a reexamination of data from the literature and from specimens in museum and personal collections. Also, we redescribed morphology of poorly known taxa from the arid regions of the Old World—Moina belli Gurney, 1904 and M. kaszabi Forró, 1988 and clarify their diagnostic morphological characters and distributional ranges. We found that M. belli and M. kaszabi are morphologically very similar. In both species, setae 1 and 2 of thoracic limb I are armed bilaterally by fine, densely located short setulae. Reliable differences between M. belli and M. kaszabi concern armature of the valve posteroventral portion. Among the moinids with two resting eggs in the ephippium, M. belli and M. kaszabi are morphologically closer to M. macrocopa (Straus, 1820) and M. americana Goulden, 1968. All these species have: (1) a dorsal head pore; (2) fine long hairs on head, valve and preanal margin of postabdomen; (3) thoracic limb I of male with a long exopodite. In general, an investigated group of moinids includes both species with relatively compact and very broad distributional ranges. We concluded that maximum diversity of the moinids forming ephippia with two resting eggs is characteristic of southern portions of Palaearctic and Nearctic zoogeographical regions and approximately corresponds to subtropical climate zone. We need to underline that M. macrocopa and M. americana have a great invasive potential. Both species were anthropogenically introduced in South America and have been successfully naturalized there. Their distribution in tropical regions of the Old World and Australia requires new precise investigations. A group of moinids forming ephippia with two resting eggs can be considered as a convenient model for biogeographical reconstructions, including studies on changes in aquatic ecosystems due to global climate warming, eutrophication and the introduction of non-native species. There is no doubt that subsequent joint application of morphological and genetic data will shed more light on the global phylogeographic structure of the entire family Moinidae.

Do agroecological practices control Ralstonia solanacearum wilt on solanaceous crops? A meta‐analysis

AbstractThe effectiveness of agroecological management strategies (AEMS) in controlling bacterial wilt caused by Ralstonia solanacearum species complex (RSSC) remains a critical question. A quantitative review was conducted based on publications reporting agroecological bacterial wilt management practices under on‐station or on‐farm field conditions in electronic libraries, without geographical restrictions, on tomato, pepper, eggplant and potato. After applying inclusion and exclusion criteria, 48 papers were retained, resulting in 644 and 146 observations of bacterial wilt incidence (BWI) and yield, respectively. The effectiveness of AEMS for each crop was evaluated based on BWI and crop yield. The effect size was calculated as the natural logarithm of the response ratio, and confidence intervals were determined by bootstrapping. Varietal control, biological control (used of biological control agents) and combinations of many AEMS were the most reported practices, both under on‐station and on‐farm conditions. The use of plant extracts (Thymus spp., Crotalaria spp.), grafting, solarization, soil amendments (manure, compost) and crop rotations (with maize, beans) were also reported. All AEMS significantly reduced bacterial wilt incidence and increased yields compared to the untreated plots. Grafting, combinations of control methods, varietal control and biological control were the most effective agroecological practices in reducing BWI and increasing yield in tomato and eggplant. Varietal control was the most effective compared to biological control on pepper. The effectiveness of AEMS also varied with crop susceptibility and origin, climatic zone and soil acidity. This study highlights the potential of AEMS in reducing BWI and increasing crop yield in infested soils.

Cross pathogenicity, host range and molecular characteristics of Fusarium oxysporum species complex populations isolated from tobacco in Jilin Province, China

AbstractFusarium wilt of tobacco (FWT) is a globally significant disease responsible for major losses in tobacco yield and quality. A total of 320 Fusarium oxysporum species complex (FOSC) isolates derived from five tobacco‐growing regions in Jilin province, China, have been confirmed as the predominant pathogens causing FWT, including F. tobaccum, F. cugenangense, F. odoratissimum and F. foetens. In this study, the results indicated that differences in the virulence of the representative isolates from tobacco from the same Fusarium species were significant. Aside from infecting tobacco, the virulence of these representative FOSC isolates differed on chilli and other crops, and they were not pathogenic or were weakly pathogenic to a further 20 crops. Six strains of formae speciales (ff. sp.) of F. oxysporum had the strongest virulence on their original hosts and were not or weakly pathogenic to tobacco. Joint analysis of the pg1‐pg5‐pgx1‐pgx4 genes indicated that 21 isolates of F. cugenangense were divided into four branches, which were clustered with different ff. sp. of F. oxysporum; five isolates of F. foetens were clustered in a branch with f. sp. fragariae, which were not pathogenic to strawberries; six isolates of F. tobaccum and five isolates of F. odoratissimum comprised independent branches and did not cluster with any other f. sp. of F. oxysporum. In sum, none of the FOSC isolates causing FWT in Jilin exhibited tobacco specificity. Our findings further confirmed that FOSC isolates from tobacco could be distinguished into F. tobaccum, F. cugenangense, F. odoratissimum and F. foetens.

Colletotrichum Species Associated with Apple Bitter Rot and Glomerella Leaf Spot: A Comprehensive Overview.

Species of the genus Colletotrichum are among the most important plant pathogens globally, as they are capable of infecting many hosts-apple (Malus spp.) and other fruit and woody plant species-but also vegetable crops, cereals, legumes, and other annual and perennial herbaceous plants. The apple (Malus spp.) is attacked by various species from the genus Colletotrichum, whereby 27 different species from this genus have been described as the causative agents of apple bitter rot (ABR) and 15 as the cause of Glomerella leaf spot (GLS). These species generally belong to one of three species complexes: Colletotrichum acutatum, Colletotrichum gloeosporioides, and Colletotrichum boninense. The largest number of apple pathogens of the genus Colletotrichum belong to the species complex C. acutatum and C. gloeosporioides. However, further data on these species and the interactions between the species complexes of the genus Colletotrichum that cause these two apple diseases is needed for the development of effective control measures, thus ensuring successful and profitable apple cultivation. To contribute to this endeavor, a comprehensive review of the causative agents of ABR and GLS from the genus Colletotrichum is provided. In addition to presenting the species' current names, distribution, economic significance, and the symptoms they cause in apple, their development cycle, epidemiology, and molecular detection strategies are described, with a particular emphasis on control measures.