Not surprisingly, this rust fungus has been extensively studied. Symptoms of sorghum downy mildew include chlorosis, shredding of. Within brazil, it was initially restricted to the southern region. A lichenicolous species of pleospora ascomycota and a key to the fungi invading physcia species. Pathogenic and molecular variability among isolates of p. Merging ssr and ardra data resulted in 3 clusters, which resembled. Infected sorghum leaves kept in darkness after completion of the previous crop of the spores, did not sporulate. On 73% of nights when conidia were detected rain had fallen within the. The pathogen is a fungallike protist in the oomycota, or water mold, class. Rapid and specific detection of peronosclerospora sorghi in maize seeds by conventional and realtime pcr. Parasitology terms a parasite is an organism that obtains food and shelter from another organism and derives all benefits from this association.
Seed transmission of maize downy mildew peronosclerospora. The pathogen is disseminated in many tropical and subtropical regions all around the world, causing considerable losses when conditions are favourable for its development or susceptible cultivars are used. Philippine downy mildew of maize caused by the oomycete peronosclerospora philippinensis is a destructive disease of corn in tropical asia. Griffingconcept of general and specific combining ability in reaction to diallel. Schwinn cibageigy ltd, agricultural division, 4002 basel, switzerland and botanisches institul. Commonly known as philippine downy mildew, this disease is caused by the species peronosclerospora philippinensis of the fungallike protist class oomycetes, which also has members such as water molds and phytophthora infestans, which caused the potato blight that led to the great irish famine. Long, narrow, parallelsided, tan or graytotan or yellow spots, up to 12 by 2 to 5 cm, may merge forming large gray blotches with irregular margins that kill the leaves. Peronosclerospora philippinensis downy mildew of maize. Philippine downy mildew, peronosclerospora philippinensis. Heritability of resistance in maize to sorghum downy mildew. Report of the corn research center tainan dias yumi yenchui chunghsin yenchiu huipao, no. Early infection stages of the downy mildew fungi sclerospora. Enfermedades del cultivo del maiz martin urbina chavarria. Pdf peronosclerospora sorghi, o agente etiologico do mildio.
Peronosporaceae definition is a family of parasitic fungi order peronosporales in which the conidiophores form outside the epidermis of the host and develop conidia or sporangia singly or in clusters but never in chains. However, absence of oospore production on maize is also the case for other peronosclerosporas. Variability of puccinia sorghi in the core corngrowing region of argentina article pdf available in tropical plant pathology 363. Morfologia bacteriana colonial y microscopica microbitos blog. Peronosclerospora philippinensis, the causal pathogen of downy mildews, is one of the major maize diseases reported in most maizegrowing countries, especially in the philippines. Executive summary philippine downy mildew of maize pdm, caused by the oomycete peronosclerospora philippinensis and brown stripe downy mildew bsdm caused by sclerophthora rayssiae var. Peronosclerospora sorghi infects susceptible plants though sexual oospores, which survive in the soil, and asexual sporangia which are disseminated by wind.
Pathotypes of peronosclerospora sorghi the american. These are two of several downy mildew diseases that occur in china, india, indonesia, nepal, pakistan. Unraveling the genetic diversity of maize downy mildew in indonesia. Production of conidia by peronosclerospora sorghi on.
Molecular identification of isolates of peronosclerospora. Two types of symptoms have been described on sorghum. Infected sorghum leaves kept in darkness after completion of the previous crop of the spores, did not sporulate in. Detection and identification of peronosclerospora sacchari in maize by dna hybridization. Likewise, bsdm can be differentiated from all of the other corn infecting peronosclerospora spp.
Black stem rust of wheat, caused by puccinia graminis f. Jul 16, 2009 the fungus peronosclerospora sorghi weston and uppal shaw infects both sorghum and maize and incites downy mildew disease. The systemic form is induced when the pathogen colonizes the meristematic foliar tissues. The fungus peronosclerospora sorghi weston and uppal shaw infects both sorghum and maize and incites downy mildew disease. Peronosclerospora maydis may be confused with other peronosclerospora spp. All structured data from the file and property namespaces is available under the creative commons cc0 license.
Covered smut is transmitted by seed contaminated by spores noble et al. Morfologia bacteriana colonial y microscopica microbitos. The reactions of 8 physiologic races on 10 differential sorghum varieties are tabulated by tarr 1962, p. Graminicolous downy mildew gdm diseases caused by the genera peronosclerospora spp. Sorghum downy mildew peronosclerospora sorghi westan and uppal shaw occurs as either systemic or localized infection fig. Roc20 a very early maturing variety with high sugar content and heavy tonnage. Peronosclerospora philippinensis prscphoverview eppo. Oeun, ks, bora, p, glaudino, n, fontes, l, tam, tt, cho, mc 2006. The host in which the parasite lives its adult and sexual stage is the. Pdf sorghum sorghum bicolor ranks as the third most important. State regulated list this map identifies those states that list this species on their regulated list. Recovery plan for philippine downy mildew and brown stripe. The fungus overwinters in corn debris on or near the soil surface. Files are available under licenses specified on their description page.
Status, challenges and tools for identification and diagnosis. Texas has a new pathotype of peronosclerospora sorghi, the cause of sorghum downy mildew. Peronosclerospora sorghi resistant to metalaxyl treatment of sorghum seed in texas. Comparative pathogenicity of sclerospora sacchari and s. Cultural control and sanitary methods in view of the epidemiological knowledge of sugarcane downy mildew, it has been recommended that control measures include removal of infected maize and other hosts within at least 42 m of newly sown seed outside the range of conidial dissemination. Peronosclerospora sorghi, the causal agent of sorghum downy.
Peronosclerospora sorghi sorghum downy mildew cabi. Propuestas cryptococcus neoformans pdf abstract cryptococcus neoformans, the etiological agent of cryptococcosis. In the present study we developed a dna sequence characterized amplified region scar marker for identification of isolates of p. Sorghum downy mildew peronosclerospora sorghi symptoms the chlorotic area of leaf always includes the base of the blade, and transverse margins usually sharply defined between the diseased and healthy tissues. Peronosclerospora sorghi an overview sciencedirect topics. Otras enfermedades presentes desde hace mucho tiempo en venezuela, como las royas comunes y varias manchas foliares, han venido adquiriendo, en ocasiones, formas muy. General information about peronosclerospora sorghi prscso name authority. Philippine downy mildew peronosclerospora philippinensis philippine downy mildew peronosclerospora philippinensis is a fungal pathogen of agricultural commodities. High disease incidence has been reported in many parts in the country specifically in northern luzon and in many parts of mindanao despite breakthroughs in controlling or. Peronosclerospora sorghi prscsooverview eppo global database. Rapid and specific detection of peronosclerospora sorghi. Effect of some environmental factors on the asexual phase. Request pdf seed transmission of maize downy mildew peronosclerospora sorghi in nigeria in an area of nigeria where downy mildew of maize is present.
Peronosclerospora sorghi, produced a maximum of 10,800 conidiacm2 of diseased sorghum leaves at 100% relative humidity but only about 3600 conidia at 85% relative humidity underin vitro conditions. General information about peronosclerospora philippinensis prscph name language. Pdf variability of puccinia sorghi in the core corngrowing. Some dnabased approaches have been reported for other peronosclerospora spp. Effect of some environmental factors on the asexual phase of. The disease is caused by a soilborne fungus peronosclerospora sorghi.
Two pathotypes of peronosclerospora sorghi were identified by differential pathogenicity on seedlings of sorghum lines inoculated with conidia. Angular lesions enlarge and merge to produce large, irregular dead areas. Factors affecting the production of conidia of peronosclerospora sorghi, causing sorghum downy mildew sdm, were investigated during1993and1994in zimbabwe. Simple sequence repeat markers useful for sorghum downy mildew. Cryptococcus neoformans and 9 cryptococcus gattii strains isolated from 1980. Downy mildew caused by the obligate oomycete peronosclerospora genus, is one of the.
Peronosclerospora sorghi, the causal agent of sorghum. Differentiating pdm from the endemic maize and sorghum pathogen p. Peronosclerospora sorghi, o agente etiologico do mildio do sorgo article pdf available in fitopatologia brasileira 312 april 2006 with 59 reads how we measure reads. The sporulation was totally inhibited at 80% relative humidity and below. Systemic infection in sorghum and maize is characterized by leaf chlorosis which invariably includes the leaf. About europe pmc funders joining europe pmc governance roadmap outreach.
In relation to the maizeinfecting strain from southern nigeria, yao et al. In the southern humid zone of nigeria where the maizeinfecting strain of p. Mauchmani botanisches institul universitaet, hebestrasse i, 4056 basel switzerland f. Commonly known as philippine downy mildew, this disease is caused by the species peronosclerospora philippinensis of the fungallike protist class oomycetes, which also has members such as water molds and phytophthora infestans, which caused the potato blight that led to the great irish famine its hosts are typically grasses, cultivated and wild sorghum, sugarcane, and maize found in most of. Organic farming disease management of agricultural crops. Pdf variability of puccinia sorghi in the core corn. Parasitology terms the organism that harbors the parasite and suffers a loss caused by the parasite is a host. Status, challenges and tools for identification and. The following international journals are providing a magnificent platform to publish papers of excellent theoretical and applied research in all present and future sciences, from basic research to application development in all fields of research. Severe epidemics of downy mildew peronosclerospora sorghi on maize in cambodia, east timor and vietnam, kyungpook national university and the international corn foundation, daegu, south.
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