This document discusses the current status of species concepts and identification in downy mildews. It outlines how historical species concepts like the morphological concept and "one host-one species" concept have limitations. Recent molecular evidence supports a narrower species concept, with cryptic species found and evidence of high host specificity. While molecular tools now allow more reliable identification, developing a universal barcoding system is still a work in progress as the optimal genetic region varies between downy mildew groups. Overall a phylogenetic concept treating each distinct monophyletic lineage as a separate species seems most appropriate.
This document provides information about lady beetles and other common natural enemies of crop and garden pests in the Pacific Northwest. It describes how to identify lady beetles at different life stages and lists other similar beetles. It also briefly summarizes identification and predatory behaviors of green and brown lacewings and hoverflies. The document emphasizes the importance of monitoring pest and natural enemy populations and using integrated pest management tactics to enhance biological control.
Fauna and vegetation of a tropical rainforestsofpat
Tropical rainforests are home to over half of the world's species and play an important role in regulating global weather and storing carbon. They are under threat, having been reduced to less than 5% of the original coverage. The document then describes some examples of the rich biodiversity found in tropical rainforests, including animals like the golden lion tamarin, jaguar, capybara and poison dart frogs. It also discusses plant life, highlighting carnivorous pitcher plants, orchids, bromeliads and other vegetation that provide shelter and food for rainforest wildlife.
Economic Importance of Plant Parasitic NematodesDr. Vijay Joshi
This document discusses plant parasitic nematodes and their economic importance. It notes that nematodes are tiny worm-like organisms that can feed on plants either inside their tissues as endoparasites or outside as ectoparasites. The top 10 most economically important nematodes worldwide and in India are listed. It is estimated that plant parasitic nematodes cause over $100 billion in global crop losses annually. The document discusses the various types of nematode infections and damage they cause to plant physiology. It provides details on the life cycles and morphology of major nematode genera like root-knot, cyst and lesion nematodes. Integrated chemical and biological management options for controlling nematodes are also presented.
This document provides information on various insect pests that affect plants. It discusses the taxonomic classification of insects, focusing on the orders Thysanoptera, Hemiptera, Homoptera, and Lepidoptera. For each order, key insect pests are described, including their life cycles, feeding behaviors, impacts on plants, and potential management strategies. The document emphasizes the importance of properly classifying insect species and understanding insect-plant interactions to effectively address pest issues.
This document provides information on 20 different types of fungi, including their scientific names, where they are found, what organisms they interact with, and interesting facts. Some fungi discussed are edible mushrooms, while others are pathogens that infect plants or animals. The fungi have a variety of structures and life cycles, and several are used in food, research, or have cultural significance.
B.Sc. Agri II IN U-1 Introduction of NematologyRai University
This document provides an overview of the classification and important plant parasitic nematodes. It discusses the classification of nematodes by habitat, including above ground feeders, endoparasitic, semiendoparasitic, and ectoparasitic below ground feeders. Nine economically important plant parasitic nematodes are then described in more detail, including their systematic position, morphology, symptoms caused, and control methods. These include root-knot, reniform, root-lesion, spiral, cyst, dagger, rice stem, citrus, and burrowing nematodes.
This document summarizes a seminar presentation about plant-microbe interactions given by Manisha Thakur. It discusses how plants constantly encounter biotic and abiotic stresses. Microbes that colonize plants can have pathogenic, symbiotic, or associative relationships. Specific examples provided include mutualistic relationships like rhizobia in root nodules, and types of pathogenic relationships such as necrotrophy and biotrophy. The document also discusses concepts like the rhizosphere and how root exudates influence microbial communities in and around plant roots and leaves.
This document summarizes key differences between protozoal and helminthic infections and provides details on fungi and protozoa. It notes that parasitic diseases are more common in tropical countries but increasingly prevalent in the US. Immune responses to parasites are described as activated but seldom able to rid the body of infection. Fungi are introduced as eukaryotic, heterotrophic microbes that can be pathogenic, causing diseases through decomposition, parasitism, or toxin production. Their morphologies and modes of sexual and asexual reproduction are outlined. Common pathogenic fungi are described along with their associated diseases. Characteristics and examples of protozoa are also provided, focusing on those that are pathogenic to humans.
This document provides information about lady beetles and other common natural enemies of crop and garden pests in the Pacific Northwest. It describes how to identify lady beetles at different life stages and lists other similar beetles. It also briefly summarizes identification and predatory behaviors of green and brown lacewings and hoverflies. The document emphasizes the importance of monitoring pest and natural enemy populations and using integrated pest management tactics to enhance biological control.
Fauna and vegetation of a tropical rainforestsofpat
Tropical rainforests are home to over half of the world's species and play an important role in regulating global weather and storing carbon. They are under threat, having been reduced to less than 5% of the original coverage. The document then describes some examples of the rich biodiversity found in tropical rainforests, including animals like the golden lion tamarin, jaguar, capybara and poison dart frogs. It also discusses plant life, highlighting carnivorous pitcher plants, orchids, bromeliads and other vegetation that provide shelter and food for rainforest wildlife.
Economic Importance of Plant Parasitic NematodesDr. Vijay Joshi
This document discusses plant parasitic nematodes and their economic importance. It notes that nematodes are tiny worm-like organisms that can feed on plants either inside their tissues as endoparasites or outside as ectoparasites. The top 10 most economically important nematodes worldwide and in India are listed. It is estimated that plant parasitic nematodes cause over $100 billion in global crop losses annually. The document discusses the various types of nematode infections and damage they cause to plant physiology. It provides details on the life cycles and morphology of major nematode genera like root-knot, cyst and lesion nematodes. Integrated chemical and biological management options for controlling nematodes are also presented.
This document provides information on various insect pests that affect plants. It discusses the taxonomic classification of insects, focusing on the orders Thysanoptera, Hemiptera, Homoptera, and Lepidoptera. For each order, key insect pests are described, including their life cycles, feeding behaviors, impacts on plants, and potential management strategies. The document emphasizes the importance of properly classifying insect species and understanding insect-plant interactions to effectively address pest issues.
This document provides information on 20 different types of fungi, including their scientific names, where they are found, what organisms they interact with, and interesting facts. Some fungi discussed are edible mushrooms, while others are pathogens that infect plants or animals. The fungi have a variety of structures and life cycles, and several are used in food, research, or have cultural significance.
B.Sc. Agri II IN U-1 Introduction of NematologyRai University
This document provides an overview of the classification and important plant parasitic nematodes. It discusses the classification of nematodes by habitat, including above ground feeders, endoparasitic, semiendoparasitic, and ectoparasitic below ground feeders. Nine economically important plant parasitic nematodes are then described in more detail, including their systematic position, morphology, symptoms caused, and control methods. These include root-knot, reniform, root-lesion, spiral, cyst, dagger, rice stem, citrus, and burrowing nematodes.
This document summarizes a seminar presentation about plant-microbe interactions given by Manisha Thakur. It discusses how plants constantly encounter biotic and abiotic stresses. Microbes that colonize plants can have pathogenic, symbiotic, or associative relationships. Specific examples provided include mutualistic relationships like rhizobia in root nodules, and types of pathogenic relationships such as necrotrophy and biotrophy. The document also discusses concepts like the rhizosphere and how root exudates influence microbial communities in and around plant roots and leaves.
This document summarizes key differences between protozoal and helminthic infections and provides details on fungi and protozoa. It notes that parasitic diseases are more common in tropical countries but increasingly prevalent in the US. Immune responses to parasites are described as activated but seldom able to rid the body of infection. Fungi are introduced as eukaryotic, heterotrophic microbes that can be pathogenic, causing diseases through decomposition, parasitism, or toxin production. Their morphologies and modes of sexual and asexual reproduction are outlined. Common pathogenic fungi are described along with their associated diseases. Characteristics and examples of protozoa are also provided, focusing on those that are pathogenic to humans.
Predators and parasitoids go through several steps in host-seeking behaviour: host habitat location, host location within the habitat, host acceptance if suitable stimuli are present, and host suitability. Host habitat location involves cues like attractants that guide insects to areas likely containing hosts, while host location relies on senses like smell and touch to find hosts. Hosts can be rejected if too young/old, wrong size, diseased, or already parasitized. Even accepted hosts may not support development if nutritionally or physically unsuitable.
"Bio - Warfare During Host Pathogen Interactions in Indigenous Crop Plants" b...Md. Kamaruzzaman
This is a analysis of some collected information of the subject of my M.S. theory semester. Course title was Plant Pathogenesis and Genetics of Plant Pathogens
Commonly used European and western country used that predatory mite.
In especially green house crops to manage phytophagous mite along with thrips.
Predatory mites deserve special mention in an agricultural country like India, where agriculture is always under threat of constant pest attack.
Predatory mites of the family phytoseiidae constitute a highly significant beneficial group on account of their vital role in the maintenance of pest population below EIL.
Predatory mites are now valued with growers worldwide as natural enemies that provide effective pest control in green house and on agricultural crops
Phytoseiid mites have received global attention since the 1950’s.
The species of Phytoseiidae are potentially important as a biotic factor in the control of phytophagous mites particularly Tetranychid and Eriophid mites.
Mass multiplication
This document defines and describes different types of parasitism. It begins by defining parasitism as a relationship between species where one benefits at the expense of the other. It then describes 8 types of parasitism: obligate, facultative, ectoparasitism, endoparasitism, mesoparasitism, epiparasitism, brood parasitism, and social parasitism. Each type is defined and an example is provided, such as head lice for ectoparasitism and Plasmodium for endoparasitism. The document concludes by thanking the reader.
This document defines and describes different types of parasitism. It begins by defining a parasite as an organism that lives on or in another organism and obtains food for growth and reproduction. The main types discussed are ectoparasites, which live on the external surface of the host, and endoparasites, which live inside host cells or tissues. Other types include destructive parasites, which kill their host, and balanced parasites, which obtain nutrients without killing the host. Facultative parasites are normally saprophytic but can parasitize under conditions. Broad categories of parasitism include biotrophs, hemi-biotrophs, and necrotrophs/perthotrophs, which kill host
KY: Attracting Butterflies with Native PlantsSotirakou964
Butterflies are beautiful insects that people enjoy attracting to their gardens. To successfully attract butterflies, gardeners must understand butterfly biology and ecology. Specifically, they must plant native species that caterpillars use as food sources so the butterflies will come to lay eggs. Common caterpillar food plants include members of the carrot family for black swallowtails and milkweeds for monarchs. By providing larval host plants that match the local butterfly species, gardeners can support the butterfly life cycle and attract more of these colorful insects to enjoy.
The document defines different types of mycorrhizal associations between fungi and plant roots that provide benefits to both organisms. It describes arbuscular mycorrhizas formed by Glomeromycota fungi in plant roots, which usually have structures called arbuscules and vesicles. It also discusses ectomycorrhizal associations with a Hartig net between root cells and a fungal mantle on root surfaces. The document provides examples of orchid mycorrhizas with fungal coils inside thin root cells, and ericoid mycorrhizas in the plant family Ericaceae with fungal coils or hyphae in root cells.
2-Species concept.pdf for botany bs 5th samesterkhanmuhammadm463
The document discusses various concepts of what constitutes a species, including the taxonomic/morphological species concept, biological species concept, and phylogenetic species concept. It also describes microspecies/satellite species which are small peripheral populations that evolve distinctively from the central populations due to environmental conditions. Species aggregates are discussed as groups of closely related species that are difficult to distinguish and are often grouped together. Infraspecific categories below the species level like subspecies, varieties, forms are also outlined.
This document describes several genera of oomycetes that cause downy mildew diseases in plants. It provides details on their taxonomic classification, structures and life cycles. Key points include:
- Plasmopara viticola causes downy mildew of grapes and produces both asexual zoospores and sexual oospores.
- Pseudoperonospora cubensis causes downy mildew of cucurbits like cucumber and produces sporangia and infects via intercellular hyphae.
- Bremia lactucae causes downy mildew of lettuce and has asexual sporangia and can reproduce sexually or asexually via oospores.
This file gives general information about characteristics and importance of the fungi belonging to the order Perenosporalees and its major families albuginaceae, perenosporaceae and pythiaceae
1. Microevolution between populations can lead to differences between them, and over time macroevolution and new species.
2. A polytypic species is a single species composed of geographically and morphologically different populations that evolved through microevolution.
3. Most widely distributed animal species are polytypic, consisting of multiple subspecies that are allopatric or allochronic populations differing from the main type population. Establishing polytypic species and delineating subspecies is challenging and sometimes arbitrary.
The document discusses different concepts of what constitutes a species, including the Biological Species Concept and Phylogenetic Species Concept. The Biological Species Concept defines a species as groups that can interbreed, with reproductive isolation maintained by intrinsic barriers. The Phylogenetic Species Concept defines species as the smallest diagnosable units that form monophyletic groups. Allopatric speciation, where physical isolation allows populations to diverge genetically, is also discussed as a primary mechanism of speciation.
This document discusses the classification and nomenclature of human parasites. It begins by explaining that parasites are scientifically classified using binomial nomenclature with their genus and species. Parasites are further classified into taxonomic groups like phylum, class, order, family and genus based on their life cycles and morphological characteristics.
The document then provides examples of how major groups of human parasites are classified, including protozoa (amebae, flagellates, ciliates), fungi, platyhelminthes (cestodes, trematodes), nematodes, acanthocephala, and arthropods. It notes that classifying parasites can be difficult due to lack of specimens, morphological variations, and differences
1. Microevolution leads to genetic differences between populations over time, which can result in new species through macroevolution if enough differences accumulate.
2. A polytypic species consists of multiple geographically isolated populations that have undergone microevolution, like the different tiger subspecies.
3. Recognizing polytypic species simplifies classification by reducing many similar local populations to subspecies rather than considering each a unique species. However, delineating subspecies from one another or related species remains challenging.
Species are groups of actually or potentially interbreeding populations which are reproductively isolated from other such groups. The biological species concept has been prevalent in the evolutionary literature for the last several decades and is emphasized in many college-level biology courses. It is probably the species concept most familiar to biologists in diverse fields, such as conservation biology, forestry, fisheries, and wildlife management. Species defined by the biological species concept have also been championed as units of conservation. The species concept for most phycologists is based on the morphological characters and hence the term ‘species’ means morphospecies. On the other hand, for evolutionary biologists, the term means biological species that can be defined as a reproductive community of populations (reproductively isolated from others) that occupy a specific niche in Nature.
This document discusses species concepts and speciation. It defines key terms like phenon, taxon, and category. It describes several species concepts including the typological, nominalistic, and biological species concepts. The biological species concept defines a species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups. Speciation occurs through lineage splitting that produces two or more separate species and can be caused by populations becoming isolated geographically, temporally, behaviorally, ecologically, or reproductively.
This article examines how non-vocal white-bellied copper-striped skinks respond to playbacks of predator vocalizations, heterospecific alarm calls, and non-alarm social vocalizations. The skinks reduced looking and increased bloating in response to alarm calls from red-vented bulbuls, but did not significantly respond to social calls from bulbuls or vocalizations from potential predators. This suggests that as non-vocal lizards, skinks likely rely on heterospecific alarm calls for information about predator presence and location.
Mimicry, polymorphism and molecular phylogeny...Saumya Sharma
Mimicry is when one species imitates another for protection. There are three main types of mimicry: Batesian mimicry occurs when a palatable species mimics an unpalatable one for protection from predators. Mullerian mimicry happens when multiple unpalatable species converge to resemble each other. Protective coloration is when an organism mimics its environment for camouflage. Polymorphism is when multiple forms of the same species exist in a population at once, differing in morphology, physiology or biochemistry. Molecular phylogeny uses molecular data like DNA to construct evolutionary trees showing relationships between organisms.
Predators and parasitoids go through several steps in host-seeking behaviour: host habitat location, host location within the habitat, host acceptance if suitable stimuli are present, and host suitability. Host habitat location involves cues like attractants that guide insects to areas likely containing hosts, while host location relies on senses like smell and touch to find hosts. Hosts can be rejected if too young/old, wrong size, diseased, or already parasitized. Even accepted hosts may not support development if nutritionally or physically unsuitable.
"Bio - Warfare During Host Pathogen Interactions in Indigenous Crop Plants" b...Md. Kamaruzzaman
This is a analysis of some collected information of the subject of my M.S. theory semester. Course title was Plant Pathogenesis and Genetics of Plant Pathogens
Commonly used European and western country used that predatory mite.
In especially green house crops to manage phytophagous mite along with thrips.
Predatory mites deserve special mention in an agricultural country like India, where agriculture is always under threat of constant pest attack.
Predatory mites of the family phytoseiidae constitute a highly significant beneficial group on account of their vital role in the maintenance of pest population below EIL.
Predatory mites are now valued with growers worldwide as natural enemies that provide effective pest control in green house and on agricultural crops
Phytoseiid mites have received global attention since the 1950’s.
The species of Phytoseiidae are potentially important as a biotic factor in the control of phytophagous mites particularly Tetranychid and Eriophid mites.
Mass multiplication
This document defines and describes different types of parasitism. It begins by defining parasitism as a relationship between species where one benefits at the expense of the other. It then describes 8 types of parasitism: obligate, facultative, ectoparasitism, endoparasitism, mesoparasitism, epiparasitism, brood parasitism, and social parasitism. Each type is defined and an example is provided, such as head lice for ectoparasitism and Plasmodium for endoparasitism. The document concludes by thanking the reader.
This document defines and describes different types of parasitism. It begins by defining a parasite as an organism that lives on or in another organism and obtains food for growth and reproduction. The main types discussed are ectoparasites, which live on the external surface of the host, and endoparasites, which live inside host cells or tissues. Other types include destructive parasites, which kill their host, and balanced parasites, which obtain nutrients without killing the host. Facultative parasites are normally saprophytic but can parasitize under conditions. Broad categories of parasitism include biotrophs, hemi-biotrophs, and necrotrophs/perthotrophs, which kill host
KY: Attracting Butterflies with Native PlantsSotirakou964
Butterflies are beautiful insects that people enjoy attracting to their gardens. To successfully attract butterflies, gardeners must understand butterfly biology and ecology. Specifically, they must plant native species that caterpillars use as food sources so the butterflies will come to lay eggs. Common caterpillar food plants include members of the carrot family for black swallowtails and milkweeds for monarchs. By providing larval host plants that match the local butterfly species, gardeners can support the butterfly life cycle and attract more of these colorful insects to enjoy.
The document defines different types of mycorrhizal associations between fungi and plant roots that provide benefits to both organisms. It describes arbuscular mycorrhizas formed by Glomeromycota fungi in plant roots, which usually have structures called arbuscules and vesicles. It also discusses ectomycorrhizal associations with a Hartig net between root cells and a fungal mantle on root surfaces. The document provides examples of orchid mycorrhizas with fungal coils inside thin root cells, and ericoid mycorrhizas in the plant family Ericaceae with fungal coils or hyphae in root cells.
2-Species concept.pdf for botany bs 5th samesterkhanmuhammadm463
The document discusses various concepts of what constitutes a species, including the taxonomic/morphological species concept, biological species concept, and phylogenetic species concept. It also describes microspecies/satellite species which are small peripheral populations that evolve distinctively from the central populations due to environmental conditions. Species aggregates are discussed as groups of closely related species that are difficult to distinguish and are often grouped together. Infraspecific categories below the species level like subspecies, varieties, forms are also outlined.
This document describes several genera of oomycetes that cause downy mildew diseases in plants. It provides details on their taxonomic classification, structures and life cycles. Key points include:
- Plasmopara viticola causes downy mildew of grapes and produces both asexual zoospores and sexual oospores.
- Pseudoperonospora cubensis causes downy mildew of cucurbits like cucumber and produces sporangia and infects via intercellular hyphae.
- Bremia lactucae causes downy mildew of lettuce and has asexual sporangia and can reproduce sexually or asexually via oospores.
This file gives general information about characteristics and importance of the fungi belonging to the order Perenosporalees and its major families albuginaceae, perenosporaceae and pythiaceae
1. Microevolution between populations can lead to differences between them, and over time macroevolution and new species.
2. A polytypic species is a single species composed of geographically and morphologically different populations that evolved through microevolution.
3. Most widely distributed animal species are polytypic, consisting of multiple subspecies that are allopatric or allochronic populations differing from the main type population. Establishing polytypic species and delineating subspecies is challenging and sometimes arbitrary.
The document discusses different concepts of what constitutes a species, including the Biological Species Concept and Phylogenetic Species Concept. The Biological Species Concept defines a species as groups that can interbreed, with reproductive isolation maintained by intrinsic barriers. The Phylogenetic Species Concept defines species as the smallest diagnosable units that form monophyletic groups. Allopatric speciation, where physical isolation allows populations to diverge genetically, is also discussed as a primary mechanism of speciation.
This document discusses the classification and nomenclature of human parasites. It begins by explaining that parasites are scientifically classified using binomial nomenclature with their genus and species. Parasites are further classified into taxonomic groups like phylum, class, order, family and genus based on their life cycles and morphological characteristics.
The document then provides examples of how major groups of human parasites are classified, including protozoa (amebae, flagellates, ciliates), fungi, platyhelminthes (cestodes, trematodes), nematodes, acanthocephala, and arthropods. It notes that classifying parasites can be difficult due to lack of specimens, morphological variations, and differences
1. Microevolution leads to genetic differences between populations over time, which can result in new species through macroevolution if enough differences accumulate.
2. A polytypic species consists of multiple geographically isolated populations that have undergone microevolution, like the different tiger subspecies.
3. Recognizing polytypic species simplifies classification by reducing many similar local populations to subspecies rather than considering each a unique species. However, delineating subspecies from one another or related species remains challenging.
Species are groups of actually or potentially interbreeding populations which are reproductively isolated from other such groups. The biological species concept has been prevalent in the evolutionary literature for the last several decades and is emphasized in many college-level biology courses. It is probably the species concept most familiar to biologists in diverse fields, such as conservation biology, forestry, fisheries, and wildlife management. Species defined by the biological species concept have also been championed as units of conservation. The species concept for most phycologists is based on the morphological characters and hence the term ‘species’ means morphospecies. On the other hand, for evolutionary biologists, the term means biological species that can be defined as a reproductive community of populations (reproductively isolated from others) that occupy a specific niche in Nature.
This document discusses species concepts and speciation. It defines key terms like phenon, taxon, and category. It describes several species concepts including the typological, nominalistic, and biological species concepts. The biological species concept defines a species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups. Speciation occurs through lineage splitting that produces two or more separate species and can be caused by populations becoming isolated geographically, temporally, behaviorally, ecologically, or reproductively.
This article examines how non-vocal white-bellied copper-striped skinks respond to playbacks of predator vocalizations, heterospecific alarm calls, and non-alarm social vocalizations. The skinks reduced looking and increased bloating in response to alarm calls from red-vented bulbuls, but did not significantly respond to social calls from bulbuls or vocalizations from potential predators. This suggests that as non-vocal lizards, skinks likely rely on heterospecific alarm calls for information about predator presence and location.
Mimicry, polymorphism and molecular phylogeny...Saumya Sharma
Mimicry is when one species imitates another for protection. There are three main types of mimicry: Batesian mimicry occurs when a palatable species mimics an unpalatable one for protection from predators. Mullerian mimicry happens when multiple unpalatable species converge to resemble each other. Protective coloration is when an organism mimics its environment for camouflage. Polymorphism is when multiple forms of the same species exist in a population at once, differing in morphology, physiology or biochemistry. Molecular phylogeny uses molecular data like DNA to construct evolutionary trees showing relationships between organisms.
This document discusses sympatric speciation, which is the evolution of reproductive isolation between populations of the same species living in the same geographic area. It provides examples of sympatric speciation occurring in apple maggot flies, bacteria, Midas cichlid fish, and orca whales. Polyploidy, a process where organisms contain more than two sets of chromosomes, is also discussed as a mechanism for instant sympatric speciation, especially in plants. The document outlines criteria for determining if speciation occurred sympatrically and mechanisms that can drive the process, such as changes in habitat or food preference.
Conventional & newer aspects in taxonomyManideep Raj
1. Taxonomy uses various conventional and newer approaches to characterize and identify species based on different types of characters.
2. Morphological, embryological, ecological, behavioral, and geographic approaches are discussed as important taxonomic methods. Each approach uses different observable traits.
3. The use of multiple character sets from different approaches provides a more accurate fit between species taxa and evolutionary relationships than using only one type of character.
This document discusses different concepts of what defines a species in biology. It outlines five main species concepts: biological, morphological, genetic, ecological, and phylogenetic. The biological species concept defines a species as groups that can interbreed, while the morphological concept defines species based on shared physical traits. The genetic concept focuses on genetic compatibility and isolation between groups. The ecological concept examines what ecological niche organisms occupy. Finally, the phylogenetic concept defines species as clusters of organisms with a shared evolutionary ancestry. The document notes there is no consensus on a single definition and different concepts may be more applicable depending on the organism.
De Jager et al 2016 Pollinators can prefer rewarding models to mimicsMarinus De Jager
This document summarizes a study that investigated two orchid species, Disa gladioliflora and Disa ferruginea, and their potential to engage in Batesian floral mimicry with co-flowering rewarding plant species. The study measured floral traits of all species in the community to assess similarity between orchids and their putative model species. Observation of pollinator visits and choice experiments were conducted to determine if orchids and models shared pollinators, and if pollinators could discriminate between them. The results provide insights into the assumptions of Batesian floral mimicry, such as a mimic closely resembling a single model with which it shares pollinators that cannot distinguish between them.
This document summarizes the results of a molecular re-evaluation of Phytophthora species isolated during 30 years of vegetation health surveys in Western Australia. Several key findings are reported: 1) At least seven new Phytophthora species were identified that are genetically distinct from currently described species; 2) The molecular identification of many isolates did not match the original morphological identification; and 3) Several Phytophthora species newly recorded in Western Australia were identified, including P. inundata, P. gonapodyides, and P. sp. asparagi. The significance of identifying new Phytophthora species is discussed.
This document summarizes research on Phytophthora and Pythium diversity found in UK gardens. Over 25 Phytophthora species and 17 Pythium species have been identified. The most common host plants are Taxus, Rhododendron, Rubus, and Viburnum for Phytophthora, and Taxus, Prunus, Rubus, and Cornus for Pythium. Detection methods like apple baiting, nested PCR, and immunoassay were used and compared over multiple years.
This document summarizes a survey of Phytophthora and Pythium species associated with export crops in Guatemala. Samples were collected from various crops across several regions and departments of Guatemala. Six Phytophthora species (P. capsici, P. cinnamomi, P. citrophthora, P. palmivora, P. nicotianae, and P. tropicalis) and several Pythium species (Py. cucurbitacearum, Py. splendens, Py. sylvaticum, Py. ultimum, and Pythium sp.) were identified based on morphological characteristics and molecular analysis. The study provides information on the distribution and identification of
This document summarizes research on molecular taxonomy and phylogenetics of Phytophthora and Pythium species. It describes using DNA barcoding and PCR to identify oomycete communities from infected plant tissues and soil. Phylogenetic trees were constructed for Phytophthora and Pythium based on concatenated gene sequences. New Phytophthora species found include Ph. sylvatica and Ph. hungarica. Detection methods for Phytophthora ramorum and Ph. alni are also summarized. The document outlines future areas of research such as exploring oomycete diversity with non-culture techniques and linking genetic phylogeny to morphology.
The rapid expansion of global trade and travel has increased the spread of pathogens. Climate change also influences pathogen communities directly and indirectly. Sudden Oak Death is provided as an example. There are challenges in accurately identifying pathogen species, understanding pathogen diversity in nature, and facilitating global cooperation on knowledge sharing. The Phytophthora Database was created as cyberinfrastructure to support identification and monitoring of Phytophthora species through genetic fingerprinting and phenotypic data on known isolates.
1. Three new species of Pythiogeton, a genus of plant pathogenic oomycetes, were isolated from diseased ornamental plant roots in North Carolina.
2. The Pythiogeton species were characterized based on their morphology and ITS rDNA sequences.
3. A phylogenetic tree showed that the new Pythiogeton species grouped together and were more closely related to Pythium grandisporangium than the genus Phytophthora.
The document describes an ongoing study analyzing the molecular phylogeny of marine Halophytophthora species using DNA sequence data from the internal transcribed spacer (ITS), large subunit (LSU), and cytochrome c oxidase subunit 1 (COX1) regions. Phylogenetic trees were constructed from the sequence alignments to examine relationships between Halophytophthora species and other oomycete genera. BLAST searches were also performed with some ITS sequences to identify close matches in GenBank.
This document summarizes the results of a molecular re-evaluation of Phytophthora species isolated from natural ecosystems in Western Australia over 30 years. It was found that many isolates previously identified by morphology do not match the DNA identification. At least seven new Phytophthora species were discovered that are genetically distinct from currently described species. Several known Phytophthora species were also recorded for the first time in Western Australia. Further research is needed to understand the threat posed by these new species to biodiversity and determine factors like their host range, distribution, and whether any are introduced or hybrid species.
This document summarizes research on Phytophthora taxon Agathis (PTA), a pathogen threatening New Zealand's iconic kauri trees. PTA was first identified in 1972 infecting trees on Great Barrier Island. The pathogen causes foliage yellowing, crown thinning, bleeding trunk lesions, and tree death. Molecular analysis identified PTA as a unique, unnamed species closely related to P. katsurae. Pathogenicity tests showed PTA was lethal to kauri seedlings while having little effect on other tree species. Field surveys found a kauri forest with abundant PTA infections, suggesting the pathogen may shift the forest composition by preferentially killing kauri. PTA poses a serious threat to kauri forests and
The document describes a phylogenetic analysis of Pythium taxa using nuclear and mitochondrial DNA markers. It proposes a new genus, Phytopythium gen. nov., based on the analysis which separated some Pythium taxa into a distinct clade. The analysis included 80 Pythium species and relatives and involved sequencing nuclear 28S rDNA and mitochondrial cytochrome c oxidase I (COI) gene regions.
The document discusses the history and future of the World Oomycetes Genetic Resource Collection (WOGRC), formerly known as the World Phytophthora Collection (WPC). It describes how the WPC was originally founded in the 1960s with 600 accessions and has since grown significantly to over 9,500 Phytophthora accessions representing over 95 species. The collection also includes over 900 Pythium accessions representing 97 species. Cultures are preserved through cryopreservation at liquid nitrogen temperatures. The collection serves as an important genetic resource for research on Phytophthora and Pythium species.
1) The study analyzed the genetic diversity of Phytophthora ramorum isolates from Belgium using AFLP and microsatellite markers.
2) For AFLP, 71 of 79 isolates belonged to a single genotype, while microsatellites identified 26 genotypes among 314 isolates, with 74% belonging to one genotype.
3) The results indicate low genetic diversity within the Belgian P. ramorum population.
This document summarizes the current state of phylogenetic research on the genus Phytophthora. It discusses how genomics and high-throughput sequencing have provided new insights into the early evolution and relationships within the genus. Several key findings are highlighted, including that genomics studies have identified genes in Phytophththora species similar to those in red algae and cyanobacteria, suggesting a complex evolutionary history. Finer-scale phylogenetic analyses using multiple genes are providing a more robust phylogeny with some clades showing distinct geographic distributions.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
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Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
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Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
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* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
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Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
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- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
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- How to streamline operations with automated policy checks on container images
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
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We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
Essentials of Automations: The Art of Triggers and Actions in FME
O2 Voglmayr
1. Reconsidering the species
problem in downy mildews –
where are we now?
Hermann Voglmayr
Dept. of Systematic and Evolutionary Botany,
University of Vienna, Austria
2. The current talk will focus on...
historical competing species concepts of downy
mildews, their implications and influence
influence of recent (mainly molecular) evidence
for the debate on a revised species concept in
downy mildews
the current status and shortcomings of
knowledge on biodiversity of downy mildews
the status of a molecular barcoding system
3. Multigene analysis of downy mildews
LSU (D1-D3, D7-D8), cox2, ß-tubulin, NADH (3921 bp)
downy mildews
(Peronosporaceae) are likely to
Peronosporaceae
be monophyletic
downy mildews are rooted
within a paraphyletic
Phytophthora
circumscription of important
genera mostly resolved
various subgroups of downy
Phytophthora mildews highly supported
relationships between these
groups remains mostly
unresolved
from Göker et al. (2007): How do obligate parasites evolve? A multi-gene phylogenetic analysis of downy mildews
4. What are important species problems
in downy mildews?
except for economically important species, most
described species are little known and investigated
lack of sound contemporary investigations on biodiversity
lack of a sound reference for species identification
uncritical use of species names
species identification solely based on host association
uncertainties about the host ranges of species
how to delimit and define the species – is a narrow or
wide species concept more appropriate (splitting vs.
lumping)?
is the popular and commonly applied “one host family –
one parasite” concept appropriate?
5. What are the main reasons for the
species problem?
comparatively few morphological features available for
species delimitation
few morphological features are commonly variable and
overlapping
cryptic speciation appears to be common (genetically distinct
entities lack morphological distinction) – shall they be formally
classified?
obligate parasites – cannot be cultured and investigated on
artificial media
experimentally difficult - many biological experiments which
can be carried out in Phytophthora cannot practically be
applied to downy mildews (crossing experiments, recognition
reactions, nutrition requirements,...)
host range can only be examined by time-consuming
inoculation experiments
6. How many species do we have in
downy mildews?
species circumscription was in the past
rather based on personal opinion than on
facts
highly deviating species estimates on
downy mildews, depending on the species
concept (narrow versus wide):
- Peronospora: from c. 60 to more than 350
- Plasmopara: from c. 80 to 120
- Bremia: from 1 to c. 15
7. Brief history of species concepts in
downy mildews
morphological (morphometric) species concept:
species delimitation based on morphological
features/differences
problem: few morphological features available; often no
clear-cut morphological differences, but a morphological
continuum/overlap
morphological features often influenced by environment
only few „species“ morphologically distinguishable
each of these morphological „species“ would have a
wide host range
but: experimental data indicated narrow host range!
due to these problems, practically, a purely
morphological species concept was never applied in
downy mildews
8. Brief history of species concepts in
downy mildews
Gäumann‘s (1918, 1923) „biological“ species concept:
high host specialisation is considered the most important biological
feature of species
species delimitation primarily based on host species/genus, with a
combination of morphological features/differences
result: narrow “one host – one species“ concept - leads to a high
number of accepted species (splitting approach)
problems:
- host specificity often not experimentally proven
- morphometric differences between species given by Gäumann often
very small, based on few (often single) specimens
- species cannot be identified if host is unknown, new or unidentified
- misleads to species identification only by host species
not widely accepted by plant pathologists who preferred a wide
species concept
more widely applied by investigators of biodiversity
9. Brief history of species concepts in
downy mildews
Yerkes & Shaw’s (1959) “one host family-one species“ concept:
accessions from the same host family are classified within a single
species if not morphologically clearly distinct
accessions from different host families are classified as distinct
species, even if morphologically not clearly distinct
result: wide “one host family – one species” concept – leads to few
accepted species (lumping approach)
convenient approach and therefore popular and widely accepted
amongst plant pathologists and still commonly used
problems:
- misleads to species identification only by host family
- untested assumption that downy mildews from the same host family are
closely related – if not, non-related entities are classified under a single
species
- confusion about host ranges, inoculation sources, incomparable
experiments etc.
10. Modern species concepts
Biological species concept (Ernst Mayr, 1982)
species are considered/defined as reproductive
communities and separated by reproductive isolation
practically not applicable in obligate parasitic downy
mildews due to methodological difficulties (not
culturable!)
Phylogenetic species concept
nowadays the dominant concept due to rapid progress in
DNA sequencing techniques
phylogenies (trees) are used for defining species
species are defined as distinct, monophyletic entities
reproductive isolation is mirrored by genetic distance
11. Evidence from recent investigations
(1) detection of new, morphologically clearly
distinct species by thorough re-investigations
12. Plasmopara on Geranium
nu LSU rDNA 2 new species were
(published 2006) revealed, which were clearly
distinct
new species are quite
common, widespread and
sympatric with already
described species
North different species can infect
America & the same host species even
Eastern
Asia on the same host individual!
remained undetected
Boreal and
montane despite clear morphological
Eurasia differences - due to
uncritical species
determination based solely
on host association!
MP tree from Voglmayr & al. (2006), Mycological Research 110: 633-645
13. Evidence from recent investigations
(1) detection of new, clearly distinct species by
thorough re-investigations
(2) inappropriate species classification by
uncritical adherence to the “one host family –
one species” concept
14. The identity of the downy mildew of
sweet basil (Ocimum spp.)
severe outbreaks of downy mildew of basil
world-wide from about 2000 onwards.
Identified as Peronospora lamii primarily on
host family (Lamiaceae)
Peronospora lamii supposed to be the sole
species on Lamiaceae; type host: Lamium
from Heller & Baroffio, http://www.db-
based on distribution records of Peronospora
acw.admin.ch/pubs/wa_cma_03_pub_492_d.pdf lamii on the various hosts, the pathogen was
considered to be indigenous in most
European, Asian and North American
countries
therefore, the sweet basil pathogen was not
included in quarantine lists, promoting rapid
spread via infected seed lots
15. The identity of the downy mildew of
sweet basil (Ocimum spp.)
molecular phylogenetic analyses (ITS rDNA)
showed the Ocimum-Peronospora to be
markedly distinct from Peronospora lamii!
(Belbahri et al., 2005)
close but probably not conspecific with the
Peronospora from Salvia - should represent
a distinct species
the species could not be given a name
problem: altogether, more than 30
Peronospora species were described from
23 genera of Lamiaceae, for which no
molecular data are available!
pathogen origin unclear (?Africa)
Salvia
recent outbreak on Painted Nettle
Ocimum (Solenostemon scuttelarioides), followed by
rapid spread
tree from Belbahri et al. (2005), Mycological Research109: 841-848.
Pe. lamii
16. Evidence from recent investigations
(1) detection of new, clearly distinct species by
thorough re-investigations
(2) inappropriate species classification by
uncritical adherence to the “one host family –
one species” concept
(3) molecular evidence for a narrow species
concept and the re-establishment of previously
lumped species
17. Peronospora on Chenopodiaceae
Peronospora on Chenopodiaceae
commonly treated as a single species
(Pe. farinosa), following the concept
of Yerkes & Shaw (1959)
in phylogenetic analyses of DNA
data, accessions from
Chenopodiaceae are polyphyletic and
not closely related
high genetic distances between
accessions from different hosts –
evidence for high host specificity
some subtle morphological
differences present
classification as a single species
(Pe. farinosa) not tenable
tree from Choi et al. (2008), Mycopathologia 165:
155-164.
18. Peronospora on Fabaceae
ITS rDNA commonly two species accepted
(Pe. trifoliorum, Pe. viciae) (de
Bary 1864)
accessions from different host
genera/species are genetically
distinct
accessions from the same host
are genetically homogeneous
species on Fabaceae are not
monophyletic
high host specificity corroborated
narrow species concept
corroborated
some nomenclatural problems
require additional investigations
from García-Blázquez & al. (2008), Phylogeny of Peronospora, parasitic on Fabaceae, based on ITS sequences. Mycological Research, 112, 502-512
19. Hyaloperonospora – a case study
for downy mildew speciation
recently split from the genus Peronospora
(Constantinescu & Fatehi 2002), recognising 6
morphologically distinct species
numerous host species affected, mainly from
Brassicaceae
disagreement about the number of species (from 1 to
more than 100!). Gäumann (1918, 1923) applied
excessive splitting, whereas Yerkes & Shaw (1959)
accepted only one species
morphological delimitation often impossible
often lumped into a single species (H. parasitica)
species boundaries and host specificity often unclear
ideal model group for investigating host-parasite
cospeciation
20. Hyaloperonospora
ITS rDNA
Göker et al. (2004):
morphologically clearly distinct
taxa sensu Constantinescu &
Fatehi (2002) are embedded
within a paraphyletic “H.
parasitica”
accessions within a host
species/genus genetically
uniform
genetic distances between host
specific groups high and
consistent
evidence supports narrow
species concept of Gäumann,
but investigation included
comparatively few accessions
from Göker & al. (2004), Phylogeny of Hyaloperonospora based on nuclear ribosomal internal transcribed spacer sequences
21. Hyaloperonospora
ITS rDNA
Example for genetically
distinct entities:
H. parasitica: on
Capsella bursa-pastoris
(type host)
H. arabidopsidis: on
Arabidopsis thaliana
(important species on a
H. arabidopsidis genetic model plant)
H. parasitica sensu stricto
from Göker & al. (2004), Mycological Progress 3: 83-94.
22. Hyaloperonospora
ITS + extensive investigation using
nuLSU more accessions and sequence
rDNA data (Göker et al., submitted)
support previous results
narrow species delimitation
corroborated – high internal
support
the same host can be
parasitised by more than one
species (e.g. Draba verna)
no evidence for hybridisation
evidence for several
undescribed species
from Göker & al. (submitted), Species delimitation in downy mildews: the case of Hyaloperonospora in the light of nuclear ribosomal internal transcribed
spacer and large subunit sequences
23. Evidence from recent investigations
(1) detection of new, clearly distinct species by
thorough re-investigations
(2) inappropriate species classification by
uncritical adherence to the “one host family –
one species” concept
(3) molecular evidence for a narrow species
concept and the re-establishment of previously
lumped species
(4) molecular evidence for a wide species
concept and the lumping of species from
different host families
24. Reevaluation of species: Pseudoperonospora
in Pseudoperonospora
species were delimited based
on host families
Pseudoperonospora humuli on
P. “cubensis“ hop (Cannabaceae)
P. “humuli“ Pseudoperonospora cubensis
P. “cubensis“ on cucumber/melon/pumpkin
(Cucurbitaceae)
P. “humuli“
little genetic and
P. “cubensis“ morphological differences
between accessions from these
2 non-related families
molecular evidence for
conspecificity
ITS tree from Choi et al. (2005), Mycological
Research 109: 841-848.
25. Species identification and
molecular barcoding
identification by molecular tools (sequences) highly reliable
problem: there is still no consensus about the sequence region of
choice
the ITS rDNA region, a commonly used barcoding region for fungi
and also Phytophthora, works well in Peronospora and
Hyaloperonospora (especially ITS2)
however, ITS cannot be used universally for downy mildews due to
length polymorphism and presence of numerous repeats in some
lineages, in combination with amplification and sequencing
problems (e.g. in Plasmopara, Bremia).
mitochondrial DNA has better candidates (e.g. cox): high resolution,
high number of copies – can be amplified even in historic collections
however, sequence data on mitochondrial DNA still highly
fragmentary and not yet optimised. For downy mildews, specific
well-working primers need to be developed for routine use
species boundaries need to be clarified before a barcoding system
can be implemented to avoid taxonomic confusion, which
necessitates thorough taxonomic revisions
26. Conclusions
applying a phylogenetic species concept, a narrow species
circumscription seems to be more appropriate in most cases
narrow host range should be a central factor for genetic isolation
and speciation in downy mildews – strong genetic isolation barriers
due to host specificity (no evidence for hybridisation, high genetic
change)
host jumps to unrelated hosts occurred frequently, followed by rapid
genetic change
the popular “one host family-one species” concept does not conform
with a modern phylogenetic species concept. In addition, uncritical
adherence to it can have severe practical consequences and
problems (e.g. Peronospora on sweet basil)
more appropriate to formally classify cryptic species
methodologically, we currently rely on indirect evidence for genetic
isolation by molecular data (mainly sequences). Most investigations
are based on a single or few sequence regions
27. Conclusions
for identification, molecular tools are most reliable and indispensable
for downy mildews. For development of a reliable identification
system (“barcoding”), additional investigations are needed
for barcoding, the most important step is the choice of the region to
be primarily used. As ITS is inappropriate for some important
groups, mitochondrial DNA (cox?) may be a good candidate, which
needs additional investigations
a barcoding approach must be accompanied by thorough taxonomic
revisions in order to clarify and stabilise species nomenclature
additional investigations are also needed to appropriately document
the biodiversity of downy mildews. Most detailed biodiversity
investigations are more than 50 years old. Numerous distinct
species still await description.
28. Thank you for your attention!
Plasmopara euphrasiae Voglmayr & Constantinescu (2008)
29. Literature
• Belbahri, L., Calmin, G., Pawlowski, J. & Lefort F. (2005). Phylogenetic analysis and Real Time PCR detection of a presumbably
undescribed Peronospora species on sweet basil and sage. Mycological Research, 109, 1276-1287.
• Choi, Y.-J., Hong, S.-B. & Shin, H.-D. (2005). A reconsideration of Pseudoperonospora cubensis and P. humuli based on
molecular and morphological data. Mycological Research, 109, 841-848.
• Choi, Y.-J., Denchev, C. M. & Shin, H.-D. (2008). Morphological and molecular analyses support the existence of host-
specific Peronospora species infecting Chenopodium. Mycopathologia, 168, 155-164.
• Choi, Y.-J., Hong, S.-B. & Shin, H.-D. (2007c). Re-consideration of Peronospora farinosa infecting Spinacia oleracea as
distinct species, Peronospora effusa. Mycological Research, 110, 381-391.
• Gäumann, E. (1918). Über die Formen der Peronospora parasitica (Pers.) Fries. Beihefte zum Botanischen Centralblatt, 35,
395-533.
• Gäumann, E. (1923). Beiträge zu einer Monographie der Gattung Peronospora Corda. Beiträge zur Kryptogamenflora der
Schweiz, 5, 1-360.
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