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Peronospora és un gènere d'oomicets patògens de les plantes. Com tots els de la seva classe, oomicets, no són fongs vertaders (Eumycota), ja que pertanyen al regne chromalveolata.
Hi ha unes 75 espècies en aquest gènere, la majoria específiques de gèneres o famílies de plantes herbàcies dicotiledònies. Una de les espècies més conegudes de és Peronospora (Peronospora parasitica, sobre Brassicaceae) actualment s'ha vist que és una espècie del complex del gènere Hyaloperonospora.
Peronospora és un gènere d'oomicets patògens de les plantes. Com tots els de la seva classe, oomicets, no són fongs vertaders (Eumycota), ja que pertanyen al regne chromalveolata.
Hi ha unes 75 espècies en aquest gènere, la majoria específiques de gèneres o famílies de plantes herbàcies dicotiledònies. Una de les espècies més conegudes de és Peronospora (Peronospora parasitica, sobre Brassicaceae) actualment s'ha vist que és una espècie del complex del gènere Hyaloperonospora.
Peronosporo esas fungo, tipo di la familio "peronosporei".
Peronospora is a genus of oomycetes that are obligate plant pathogens of many eudicots.[1] Most species in this group produce a downy mildew disease, which can cause severe damage to many different cultivated crops, as well as wild and ornamental plants.[2] There are 19 genera that produce downy mildew, and Peronospora has been placed alongside Pseudoperonospora in the group of downy mildews with coloured conidia.[3] Peronospora has far more species than any other genus of the downy mildews.[3] However, many species have been moved from this genus to be reclassified to other or new genera.[4] Among these was the most famous Peronospora species, formerly known as Peronospora parasitica, and now known as Hyaloperonospora parasitica.[4] Now, the Peronospora species of most importance is likely the Peronospora tabacina.[5] Peronospora tabacina causes blue mold on tobacco plants and can severely reduce yields of this economically important crop to the point where it has been classified as a bioweapon.[5][3]
Peronospora was first described in 1837 by August Carl Joseph Corda, a Czech mycologist and physician, in his first of six volumes of his Icones fungorum hucusque cognitorum.[6] Since then, many of the species originally placed in Peronospora have been allocated to other genera or given rise to new genera based on new techniques such as molecular genetics.[4]
There was an epidemic in 1960 of Peronospora tabacina affecting tobacco plants leading to $25 million in losses across eleven countries, which was about 30 percent of the tobacco plants.[5] Another epidemic that was caused by Peronospora destructor reduced the yield of sweet onions by 25 percent in Georgia, USA in 2012, and led to an estimated $18.2 million in losses.[7]
Most of the Peronospora species are highly specific to their hosts and can generally be found anywhere the host plant grows, or is being cultivated.[3] A large portion of their life cycle is spent inside their host plant. Many species of Peronospora are seedborne pathogens, so the worldwide spread of Peronospora crop-plant pathogens is likely to be a result of unknowingly trading infected seeds to new areas.[3] There are also many Peronospora species that are spread by wind currents, which allows them to disperse over large distances.[3] Peronospora species prefer humid air and cool temperatures.[5]
The first stage in the Peronospora life history is the sporangia.[5] The sporangia are small spore-like structures about 65 um long that germinate a germ-tube when they are near a leaf stoma.[8][5] A germ tube will come from the sporangium and penetrate the leaf cell where it will form a haustorium.[5] The haustorium absorbs nutrients from the leaf, while hyphae invade the intercellular space, and the leaf will eventually develop a lesion.[5] These lesions often start out yellow and then turn brown as the leaf starts to undergo necrosis.[5] From here, Peronospora can undergo either asexual reproduction or sexual reproduction.[5] Asexual reproduction occurs when the air outside is moist making for favourable conditions.[5] During asexual reproduction, hyphae on the host plant will form sporangiophores, which will produce conidia.[5] The conidia will be dispersed by the wind is able to infect other plants.[5] The asexual cycle only takes five to seven days to complete.[5] Sexual reproduction occurs when the conditions are unfavourable and it needs to withstand harsh environmental conditions.[5] During sexual reproduction, the hyphae will undergo meiosis forming antheridia and oogonia, the only haploid structures in the Peronospora life history.[5] The antheridia will fuse to the oogonia, initiating plasmogamy and then karyogamy, and will result in the production of many oospores.[5] The oospores can then be dispersed by the wind to infect more plants.[5]
Both Peronospora and Pseudoperonospora are characterized by their ability to produce melanized sporangia, but Pseudoperonospora produces zoospores whereas Peronospora cannot.[3]
The model oomycete pathogen, Peronospora parasitica, used to be included in this genus, however it has been reclassified to the genus Hyaloperonospora.[3]
Some species of Peronospora have been considered for their use as a bioweapon or have been classified as potential bioweapons.[3] Peronspora somniferi was considered for its ability to devastate fields of the opium poppy, which could have targeted areas that depend on the crop.[3] The United States has classified Peronospora tabacina as a possible bioweapon, because if it were used to target the US tobacco industry, it would lead to major economic loss.[3]
Only one species in the genus Peronospora has had its genome sequenced and assembled. In 2015, Derevnina et al. performed a de novo sequence assembly of the genome of two Peronospora tabacina isolates using Illumina sequencing.[9] They estimated the genome size to be 68 Mb with a mitochondrial genome of 43 kb.[9] The two assemblies had 61.8x and 128.9x coverage for the nuclear genomes and 6,824x and 43,225x coverage for the mitochondrial genomes.[9] The mitochondrial genome only differed by seven single nucleotide polymorphisms, three small indels, and one copy number variant.[9] Using a program to predict gene models, they found 18,000 potential protein coding genes.[9]
{{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) {{cite journal}}: CS1 maint: multiple names: authors list (link) Peronospora is a genus of oomycetes that are obligate plant pathogens of many eudicots. Most species in this group produce a downy mildew disease, which can cause severe damage to many different cultivated crops, as well as wild and ornamental plants. There are 19 genera that produce downy mildew, and Peronospora has been placed alongside Pseudoperonospora in the group of downy mildews with coloured conidia. Peronospora has far more species than any other genus of the downy mildews. However, many species have been moved from this genus to be reclassified to other or new genera. Among these was the most famous Peronospora species, formerly known as Peronospora parasitica, and now known as Hyaloperonospora parasitica. Now, the Peronospora species of most importance is likely the Peronospora tabacina. Peronospora tabacina causes blue mold on tobacco plants and can severely reduce yields of this economically important crop to the point where it has been classified as a bioweapon.
Peronospora est un genre de champignons oomycètes de la famille des Peronosporaceae.
Ce genre comprend environ 75 espèces qui sont souvent des parasites biotrophes spécifiques de genres ou de familles de plantes herbacées dicotylédones. Ces pseudo-champignons pathogènes des plantes sont responsables de formes de mildiou notamment sur betterave, épinard, luzerne et trèfle, chou, tabac, soja et pois.
L'espèce type est Peronospora rumicis Corda 1837[2] .
Selon Catalogue of Life (28 février 2019)[3] :
Selon Index Fungorum (28 février 2019)[4] :
Peronospora est un genre de champignons oomycètes de la famille des Peronosporaceae.
Ce genre comprend environ 75 espèces qui sont souvent des parasites biotrophes spécifiques de genres ou de familles de plantes herbacées dicotylédones. Ces pseudo-champignons pathogènes des plantes sont responsables de formes de mildiou notamment sur betterave, épinard, luzerne et trèfle, chou, tabac, soja et pois.
L'espèce type est Peronospora rumicis Corda 1837 .
Blaðmyglur[2] (fræðiheiti: Peronospora) er ættkvísl af sjúkdómsvaldandi eggsveppum sem síkja blómplöntur. Að minnsta kosti 17 tegundir blaðmyglna lifa á Íslandi.[1]
Tegundir blaðmyglu sem fundnar eru á Íslandi.[1]
Blaðmyglur (fræðiheiti: Peronospora) er ættkvísl af sjúkdómsvaldandi eggsveppum sem síkja blómplöntur. Að minnsta kosti 17 tegundir blaðmyglna lifa á Íslandi.
Peronospora è un genere di cromisti dell'ordine delle Peronosporali appartenenti alle famiglie delle Peronosporacee (classe Oomiceti). La caratteristica morfologica differenziale di questo genere è di avere rami sporangiofori ben differenziati che si ramificano più volte; le ultime ramificazioni hanno la parte terminale appuntita. Gli sporangi germinano per micelio. Gli organismi appartenenti al genere sono noti per causare la malattia detta appunto peronospora, anche se non sono i soli a causare tale patologia delle piante.
Peronospora Corda (wroślik) – rodzaj organizmów zaliczanych do lęgniowców[1].
Pozycja w klasyfikacji według Index Fungorum: Peronosporaceae, Peronosporales, Peronosporidae, Peronosporea, Incertae sedis, Oomycota, Chromista[1].
W 2003 r. naliczono 551 gatunków należących do tego rodzaju. Jednak w wyniku badań morfologicznych i molekularnych liczne z nich przeniesiono do rodzajów Hyaloperonospora, Paraperonospora i Perofascia. W 2008 r. w obrębie rodzaju Peronospora pozostało już tylko 75 gatunków[2]. Liczba ta ciągle zmienia się wyniku dalszych badań.
Pasożyty, których plecha rozwija się pomiędzy komórkami porażonych roślin. Wytwarzają nitkowate i często rozgałęzione ssawki, za pomocą których z komórek żywiciela pobierają wodę i substancje odżywcze. Wytwarzają bezbarwne konidiofory, które w górnej części rozgałęziają się monopodialnie 2 lub 3-krotnie, zazwyczaj pod ostrym kątem. Główny trzon konidioforu i boczne gałązki często bywają faliście skręcone. Na ostatnim rozgałęzieniu znajdują się 2 lub 3 łukowato lub sigmoidalnie wygięte odcinki. Konidia powstają na szczytach ostatnich odcinkow konidioforu równocześnie. Mają dość cienkie i zazwyczaj brodawkowate ściany w różnych odcieniach brązu. Lęgnie o nieregularnym kształcie i ścianach o różnej grubości. Kuliste oospory mają bezbarwne ściany o jednakowej grubości[2].
Pasożyty roślin, głównie dwuliściennych. Wywołują u nie choroby zwane mączniakami rzekomymi[2]. Niektóre gatunki mają duże znaczenie gospodarcze, wywołują bowiem groźne choroby roślin uprawnych, m.in. takie jak: mączniak rzekomy cebuli, mączniak rzekomy grochu, mączniak rzekomy buraka, mączniak rzekomy soi, mączniak rzekomy maku, mączniak rzekomy róży, mączniak rzekomy tytoniu i inne[2][3].
Nazwy naukowe na podstawie Index Fungorum[5]. Wykaz gatunków występujących w Polsce według checklist[6].
Peronospora Corda (wroślik) – rodzaj organizmów zaliczanych do lęgniowców.
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