In previous studies, a sorghum mini core collection was scored over several years for response to colletotrichum sublineola, peronosclerospora sorghi, and sporisorium reilianum, the causal agents of the disease anthracnose, downy mildew, and head smut, respectively. Restriction fragment length polymorphism linkage analysis placed the sdm locus near loci detected by probes psbtxs552 and psbtxs361 at 5. Production of conidia by peronosclerospora sorghi on sorghum. Rapid and specific detection of peronosclerospora sorghi. Dna analysis of colletotrichum sublineolum, a fungus that. These observations and the difficulty in resolving among phylogenetically related downy mildew pathogens dramatically point out the need for simply scored markers in order to differentiate among isolates and species, and. Downy mildew dm, caused by several species of peronosclerospora and scleropthora, is a major maize zea mays l. Rapid and specific detection of peronosclerospora sorghi in. It is suggested that host plant resistance is the best solution for control of downy mildew. The invention relates to promoter regions, under the control of which transgenes can be expressed in plants in an epidermisspecific and pathogeninducible manner.
Genomewide association study in asiaadapted tropical. Peronosclerospora sorghi an overview sciencedirect topics. General information about peronosclerospora sorghi prscso name authority. Genotype dependent interspecific hybridization of sorghum. The invention relates to a method for the production of transgenic plants andor plant cells with increased pathogen resistance, characterized in that a dna sequence coding for a protein having peroxidase activity is introduced into the plant and expressed therein. Peronosclerospora maydis primary pest of corn fungallike java downy mildew. Request pdf molecular identification of isolates of peronosclerospora sorghi from maize using pcrbased scar marker the fungus peronosclerospora sorghi weston and uppal shaw infects both. The primary source of inoculum is infected seeds and airborne spores play an important role in dispersal of the pathogen. However, variability in the degree of resistance among maize genotypes to p. The relative importance of the sexual cycle in each pathosystem can vary depending on factors that include climate, host, cropping practices, patterns of pathogen migration, and the inherent biology of each species. Pathogenic and molecular variability among isolates of p. Genetic variability for resistance to sorghum downy mildew. Peronosclerospora sorghi, infecta as culturas do sorgo sorghum spp.
Peronosclerospora philippinensis prscphoverview eppo. Effects of dewperiod temperature on sporulation, germination of conidia, and systemic infection of maize by peronosclerospora sacchari. Peronosclerospora philippinensis purdue university. The causal pathogens, also called dms, are oomycetes not true fungi and are obligate parasites of higher plants. Ep1759005b1 method for increasing pathogenresistance in. Downy mildew was observed in the forest and guinea savanna ecologies, but no disease was detected in other ecologies. Rapid and specific detection of peronosclerospora sorghi in maize seeds by conventional and realtime pcr. Simple sequence repeat markers useful for sorghum downy. Downy mildew dm is a major disease of maize that causes significant yield loss in subtropical and tropical regions around the world. The crop is hampered by several biotic stresses of which sorghum downy mildew disease is one of the most devastating diseases. Shaw, is one of the widespread diseases of sorghum sorghum bicolor l. General information about peronosclerospora philippinensis prscph name language. This chapter describes the biology of sexual reproduction in phytopathogenic oomycetes and its role in disease.
Seed borne pathogens on farmersaved sorghum sorghum bicolor. Sphacelotheca sorghi, head smuth sphacelotheca reiliana and long smut tolyposporium ehrenbergii have been reported to be the most destructive pathogens, causing heavy losses in third world countries frowd, 1980. Evaluation of wild and weedy sorghums for downy mildew. A recent outbreak of sorghum downy mildew in texas has led to the discovery of both metalaxyl resistance and a new pathotype in the causal organism, peronosclerospora sorghi. Quarantine measures were invoked to prevent the spread of this potentially serious disease to other parts of australia.
The invention also relates to recombinant nucleic acid molecules, including the promoters, to transgenic plants and plant cells, transformed with said the nucleic acid molecules and to methods for producing the same. Metalaxyl apron 35sd, used as a seed treatment, was highly effective in controlling sorghum downy mildew of maize induced by peronosclerospora sorghi. On 73% of nights when conidia were detected rain had fallen within the. Genotype dependent interspecific hybridization of sorghum bicolor h. 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. The suwan1 population was initially developed from a composite pedigree of west indian, mexican, and central and south american lines, u. Systemically infected plants fail to produce panicles, resulting in complete loss of grain yield craig and odvody 1985.
These observations and the difficulty in resolving among phylogenetically related downy mildew pathogens dramatically point out the need for simply scored markers in order to differentiate among isolates and. Some dnabased approaches have been reported for other peronosclerospora spp. Comparison of host ranges of peronosclerospora philippinensis and p. Peronosclerospora sorghi infects susceptible plants though sexual oospores, which survive in the soil, and asexual sporangia which are disseminated by wind. The results indicate that genotype skv10 was found highly resistant to downy mildew recording 1. Analysis of defense genes expression in maize upon.
The diagnostic characters distinguishing peronosclerospora and sclerospora are the production of true conidia which always germinate by a germ tube in peronosclerospora, and the production of typical sporangia with a modified apical area which functions as an operculum through which. Mapping of qtl for downy mildew resistance in maize. Download as pptx, pdf, txt or read online from scribd. 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. Quantitative trait loci qtls of maize involved in mediating resistance to peronosclerospora sorghi, the causative agent of sorghum downy mildew sdm, were detected in a population of recombinant inbred lines rils derived from the zea mays l. Symptoms of a downy mildew disease were recognized on maize growing in the atherton tableland and lakeland downs areas of far north queensland in 1985. The host range of an isolate of peronosclerospora sorghi from africa, the cause of downy mildew of sorghum, was determined. Sep 24, 2014 the recent outbreak of sorghum downy mildew sdm in texas, usa caused by pathotype p3 of peronosclerospora sorghi, which is resistant to standard fungicide seed treatment, and the subsequent development of a new pathotype, p6, that overcame resistance in some hybrids, has emphasized the importance of continuing to develop new sources with genetic resistance. Abstract the main objective of this work was to identify sources of resistance in sorghum sorghum bicolor to peronosclerospora sorghi, the causal agent of downy mildew, through the evaluation of 42 sorghum genotypes under natural infection in the field. Pdf peronosclerospora sorghi, o agente etiologico do. Peronosclerospora sorghi, the downey mildew pathogen in sorghum and maize, and sclerospora graminocola in pearl millet transform the floral primordial into vegetative leafy structures causing 30 to 70% losses corresponding author.
Seed borne pathogens on farmersaved sorghum sorghum. Factors affecting the production of conidia of peronosclerospora sorghi, causing sorghum downy mildew sdm, were investigated during1993and1994in zimbabwe. Peronosclerospora sorghi, the downey mildew pathogen in sorghum and maize, and sclerospora. Abstract incidence and geographical distribution of downy mildew peronosclerospora sorghi on maize zea mays were determined in a systematic survey of 181 maize fields in the major maize. Control of sorghum downy mildew peronosclerospora sorghi. These infect both mono and dicotyledonous crops, ornamentals, and. Sorghum downy mildew caused by peronosclerospora sorghi is a major disease of maize and resistance is under the control of polygenes which necessitated identification. Peronosclerospora sorghi, the causal agent of sorghum. Peronosclerospora sorghi photos 7, 8, 9 6 these diseases are of serious concern to maize producers in several countries of asia, africa, and throughout the americas. Download pdf abstractexcerpt pdf supplementary materials downy mildew, caused by peronosclerospora sorghi is one of the important diseases affecting maize zea mays l. Methods for screening maize against downy mildew peronosclerospora sorghi methods for screening maize against downy mildew peronosclerospora sorghi cardwell, k.
Molecular identification of isolates of peronosclerospora. Peronosclerospora sacchari is the type species of the genus. The caam panel, with a set of 368 lines, was phenotyped for sdm peronosclerospora sorghi at the hotspot location of mandya, karnataka, india. Production of conidia by peronosclerospora sorghi on. Ten samples of colletotrichum sublineolum were collected to perform dna analysis using the radp primers. Incidence and geographical distribution of downy mildew on. Seed from 24 species of poaceae was collected and pregerminated in petri dishes. Pdf simple sequence repeat markers useful for sorghum. Texas has a new pathotype of peronosclerospora sorghi, the cause of sorghum downy mildew.
Us7834243b2 promoter for epidermisspecific, pathogen. Identification of downy mildew resistance gene candidates by. Incidence and geographical distribution of downy mildew peronosclerospora sorghi on maize zea mays were determined in a systematic survey of 181 maize fields in the major maize. Mapping resistance quantitative trait loci for three. No seed transmission has been detected from seeds dried prior to planting smith and. Medson chisi, gary peterson, in sorghum and millets second edition, 2019. Several downy mildew resistant maize lines have been identified.
Peronosclerospora sorghi, o agente etiologico do mildio do sorgo. Sorghum downy mildew peronosclerospora sorghi westan and uppal shaw occurs as either systemic or localized infection fig. Thakur plant pathologist coa, cskhpkv, palampur176 062 diseases of field crops and their management 11 1. Peronosclerospora sorghi prscsooverview eppo global database. I hypothesized that all ten of the radp primers would be functional in producing band sizes to show genetic differences. 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. Detection of seedborne infection of this pathogen is necessary to limit the spread of this pathogen. Identification of sources of resistance in sorghum to.
In this investigation, four local inbred maize zea mays l. Pdf rapid and specific detection of peronosclerospora. 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. Symptoms of sorghum downy mildew include chlorosis, shredding of. The subgenus peronosclerospora of sclerospora is raised to generic rank and described, the following species are transferred from sclerospora into peronosclerospora.
The pathogen was identified as peronosclerospora maydis in 1986 following examination of conidiophores with conidia and host. Information on the genetic diversity and population structure of p. Pdf simple sequence repeat markers useful for sorghum downy. Fragment patterns for the cross segregating for disease resistance differed from those for the. Ki14 is more resistant than b73 to slb, nlb, and gls. Sorghum sorghum bicolor ranks as the third most important staple cereal food crop in uganda after maize and millet. Symptom expression is greatly affected by plant age, pathogen species, and environment. Control of sorghum downy mildew peronosclerospora sorghi of. The sdm locus in sorghum accession sc325 confers resistance to downy mildew caused by pathotypes 1 and 3 of peronosclerospora sorghi. Genome wide association analysis of sorghum mini core. Mapping resistance quantitative trait loci for three foliar. The injection also comprises the use of nucleic acids coding for peroxidase in the production of transgenic plants or plant cells. The pathogen is a fungallike protist in the oomycota, or water mold, class. Balakrishna gowda university of agricultural sciences.
Identification of rflp markers linked to a gene for downy. In this study, we analyzed the quantitative trait loci qtls involved in resistance to peronosclerospora sorghi sorghum dm, p. In the present study we developed a dna sequence characterized amplified region scar marker for identification of isolates of p. Downy mildew peronosclerospora sorghi causes serious economic losses in sorghum crops. Peronosclerospora sorghi resistant to metalaxyl treatment of sorghum seed in texas. Identification of downy mildew resistance gene candidates. Evaluation of gambian and malian sorghum germplasm against. Dna extractions from the pathogen mostly showed dna with low concentrations, but there were few with. Disease of sorghum free download as powerpoint presentation. Analysis of defense genes expression in maize upon infection. Peronosclerospora species and other downy mildews of the. Peronosclerospora maydis may be confused with other peronosclerospora spp.
Peronosclerospora sorghi, to determine dna differences using rapd randomly amplified polymorphic dna primers among the samples. Pdf it is an open access article published version download 1mb abstract. Read methods for screening maize against downy mildew peronosclerospora sorghi, plant breeding on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Within brazil, it was initially restricted to the southern region. Peronosclerospora sorghi, the causal agent of sorghum downy. Genes free fulltext identification and validation of. In the southern humid zone of nigeria where the maizeinfecting strain of p.
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