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Plasmopara
''Plasmopara'' is a genus of Oomycota. ''Plasmopara'' species are plant pathogens, causing downy mildew on carrot, parsley, parsnip, chervil Chervil (; ''Anthriscus cerefolium''), sometimes called French parsley or garden chervil (to distinguish it from similar plants also called chervil), is a delicate annual herb related to parsley. It was formerly called myrhis due to its volat ..., and impatiens. References Further reading * * * External links * Water mould plant pathogens and diseases Peronosporales Water mould genera {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Viticola
''Plasmopara viticola'', the causal agent of grapevine downy mildew, is a heterothallic oomycete that overwinters as oospores in leaf litter and soil. In the spring, oospores germinate to produce macrosporangia, which under wet condition release zoospores. Zoospores are splashed by rain into the canopy, where they swim to and infect through stomata. After 7–10 days, yellow lesions appear on foliage. During favorable weather, the lesions sporulate and new secondary infections occur. Description ''Plasmopara viticola'', also known as grape downy mildew, is considered to be the most devastating disease of grapevines in climates with relatively warm and humid summers. It was first observed in 1834 by Schweinitz on ''Vitis aestivalis'' in the southeastern United States. Shortly after this first observation, the pathogen was introduced to European countries where it played a devastating role in the yield and production of their grapes, and consequently their wine. France was among th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Halstedii
''Plasmopara halstedii'' is a plant pathogen infecting sunflowers. The species is one of many pathogens commonly referred to as downy mildew. ''P. halstedii'' originated in North America. ''Plasmopara halstedii'' oospores produce a thin wall which are resistant structures, sexually produced that are essential for its continuation. After entering an area, the eradication of the pathogen is difficult due to the formation of oospores, which can remain viable in soil for many years. Hosts and symptoms ''Plasmopara halstedii'' is an obligate biotroph that attacks the flowering plants of the family Asteraceae, found to infect the genus’ ''Helianthus, Bidens, Artemisia, and Xanthium.'' The pathogen has the strongest impact on ''Helianthus,'' degrading flower yields in the species '' H. argophyllus, H. debilis, H. petiolaris and H. annuus''. ''H. annuus'', the common sunflower, is also the most common host of ''P. halstedii.'' '' Xanthium strumarium'', the common cocklebur, and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Helianthi F
''Plasmopara'' is a genus of Oomycota. ''Plasmopara'' species are plant pathogens, causing downy mildew on carrot, parsley, parsnip, chervil, and impatiens ''Impatiens'' is a genus of more than 1,000 species of flowering plants, widely distributed throughout the Northern Hemisphere and the tropics. Together with the genus ''Hydrocera'' (one species), ''Impatiens'' make up the family Balsaminaceae. .... References Further reading * * * External links * Water mould plant pathogens and diseases Peronosporales Water mould genera {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Geranii-sylvatici
''Plasmopara'' is a genus of Oomycota. ''Plasmopara'' species are plant pathogens, causing downy mildew on carrot, parsley, parsnip, chervil, and impatiens ''Impatiens'' is a genus of more than 1,000 species of flowering plants, widely distributed throughout the Northern Hemisphere and the tropics. Together with the genus ''Hydrocera'' (one species), ''Impatiens'' make up the family Balsaminaceae. .... References Further reading * * * External links * Water mould plant pathogens and diseases Peronosporales Water mould genera {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Nivea
''Plasmopara nivea'' is a plant pathogen infecting carrots. References Water mould plant pathogens and diseases Carrot diseases Species described in 1886 Peronosporales {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Obducens
''Plasmopara obducens'' is a species of oomycete that causes Impatiens downy mildew. It was first described on ''Impatiens noli-tangere'' in Germany in 1877. ''Plasmopara obducens'' is known from native species of ''Impatiens'' since the 1800s, but outbreaks on cultivated varieties of ''Impatiens walleriana'' started in 2003 in the United Kingdom and in 2004 in the United States. The outbreak spread worldwide by 2016. Morphology Sporangiophores are an average of 373 (260-484) micrometers with the first branch appearing at 197 (120-271) micrometers. Sporangia are 16 (13-18) micrometers by 13 (11-16) micrometers. Resting spores are globose with a diameter of 28 micrometers Disease symptoms Initially, leaves are stippled or yellowed. Infected leaves curl downward. A white down is often present on the underside of the leaves; buds and stems may also develop a down. Eventually, the leaves fall off the plant leaving just stems. In about a week, the plants are dead. Taxonomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impatiens
''Impatiens'' is a genus of more than 1,000 species of flowering plants, widely distributed throughout the Northern Hemisphere and the tropics. Together with the genus ''Hydrocera'' (one species), ''Impatiens'' make up the family Balsaminaceae. Common names in North America include impatiens, jewelweed, touch-me-not, snapweed and patience. As a rule-of-thumb, "jewelweed" is used exclusively for Nearctic species, and balsam is usually applied to tropical species. In the British Isles by far the most common names are impatiens and busy lizzie, especially for the many varieties, hybrids and cultivars involving ''Impatiens walleriana''. "Busy lizzie" is also found in the American literature. The invasive alien ''Impatiens glandulifera'' is commonly called policeman's helmet in the UK. Description Most ''Impatiens'' species are herbaceous annuals or perennials with succulent stems. Only a few woody species exist. Plant size varies depending on the species, from five centimetres t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downy Mildew
Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to the Peronosporaceae family. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines. The prime example is ''Peronospora farinosa'' featured in NCBI-Taxonomy and HYP3. This pathogen does not produce survival structures in the northern states of the United States, and overwinters as live mildew colonies in Gulf Coast states. It progresses northward with cucurbit production each spring. Yield loss associated with downy mildew is most likely related to soft rots that occur after plant canopies collapse and sunburn occurs on fruit. Cucurbit downy mildew only affects leaves of cucurbit plants. Symptoms Initial symptoms include large, angular or blocky, yellow areas visible on the upper surface. As lesions mature, they expand rapidly and turn brown. The under surface of infected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Lactucae-radicis
''Plasmopara lactucae-radicis'' is a plant pathogen infecting lettuce. References Water mould plant pathogens and diseases Lettuce diseases Peronosporales Species described in 1988 {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Penniseti
''Plasmopara penniseti'' is a plant pathogen infecting pearl millet. References Water mould plant pathogens and diseases Pearl millet diseases Peronosporales {{plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmopara Pygmaea
''Plasmopara pygmaea'' is a plant pathogen infecting anemones. References External links {{Taxonbar, from=Q7201995 Water mould plant pathogens and diseases Ornamental plant pathogens and diseases Peronosporales Species described in 1886 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oomycota
Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the result of contact between hyphae of male antheridia and female oogonia; these spores can overwinter and are known as resting spores. Asexual reproduction involves the formation of chlamydospores and sporangia, producing motile zoospores. Oomycetes occupy both saprophytic and pathogenic lifestyles, and include some of the most notorious pathogens of plants, causing devastating diseases such as late blight of potato and sudden oak death. One oomycete, the mycoparasite ''Pythium oligandrum'', is used for biocontrol, attacking plant pathogenic fungi. The oomycetes are also often referred to as water molds (or water moulds), although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens. O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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