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Sorghum smut disease caused by the fungus Sporisorium spp is one of the serious constrain on the productivity and quality of the sorghum grain yield especially in areas where farmers do not treat seeds before planting where grain yield loss of up to 80% is reported in different parts of the world. A Randomized Complete Block Design experiment was laid down to determine the relatively higher resistant sorghum variety and proper fungicide for management of smut disease in central Tanzania. The materials used in this experiment included some selected genotypes of sorghum (Wahi, Hakika, Macia, Langalanga Gombela and one commercial variety) with different selected fungicides (Seed Watch 20WS, Apron Star WS 42% and Snow Angel W30% DS). Results revealed that, there was high significant difference among sorghum varieties tested (P< 0.05) on disease incidence and severity whereby the lowest incidence and severity of 4.57% and 11.41% respectively were recorded on Commercial variety while highest incidence 22.18% and Severity 19.07% were in Langalanga landrace. Among fungicides the lowest disease incidence and severity (3.72 and 11.15 respectively) were observed on Apron stars fungicide (20% Metalaxyl-m, 20% Thiamethoxa and 2% Difenoconazole) while the highest incidence (36.93%) and severity (26.68%) were recorded on control. From the present study, smut management using combination of improved sorghum varieties with the application of seed dressing fungicides especially with Metalaxyl-m, Thiamethoxam and Difenoconazole is recommended for use in central part of Tanzania. [ABSTRACT FROM AUTHOR]

Barley production in the Rostov region, as well as throughout Russia, has taken its niche in agricultural production. Winter barley attracts farmers’ attention with its unpretentiousness and high productivity. The relevance of immunology used in the production of barley varieties does not decrease over time. Yield losses due to various leaf diseases can be as high as 30–50 %. The most common pathogens in the region are powdery mildew and helminthosporium blotches. The most effective and efficient way to improve the resistance of new varieties is the use of artificial infectious backgrounds. Provocative and extreme conditions promote a selection of parental forms and breeding lines that are most resistant to pathogens. The current paper has presented the results of the estimation of winter barley breeding and collection material based on the FSBSI Agricultural Research Center «Donskoy». The purpose of the study was to identify winter barley varieties and lines which are stably resistant and tolerant to leaf-stem pathogens common in the Rostov region. About 250 samples are being estimated in the period from 2019 to 2021. Over the years of study, there have been identified such varieties and lines resistant to powdery mildew as ‘Bezosty 1954’ (RF), ‘Grand’ (RF), ‘Parallelum 1967’, etc. Resistance to heliminthosporium spotting was demonstrated by the varieties ‘Bezosty 1954’ (RF), ‘Grand’ (RF), ‘Rostovsky 908’ (RF), ‘Donskoy 11’ (RF) and the lines ‘Parallelum 1967’, ‘Parallelum 1974’, ‘Pallidum 1916’, ‘Pallidum 1970’, ‘Parallelum 1960’, ‘Parallelum 1911’, ‘Nutans 1895’ and others. There were also identified such varieties with resistance or tolerance to both pathogens as ‘Grand’ (RF), ‘Sekret’ (RF), ‘Fox 1’ (RF), ‘Marusya’ (RF), ‘Karisma’ (England) and the lines ‘Bezosty 1954’, ‘Parallelum 1967’, ‘Parallelum 1974’, ‘Parallelum 2015’, ‘Parallelum 2016’, ‘Parallelum 2017’. All presented varieties and lines are proposed for use in further breeding for immunity to the studied pathogens.

Sporisorium reilianum causes head smut in sorghum. A total of 36 Senegalese sorghum accessions comprised of sorghum lines that have not been explored with response to pathotype 5 of S. reilianum were evaluated with 3 different treatments. First, seedling shoots were inoculated while still in soil with teliospores in agar, and then submerged under water at 4 days post inoculation. Signs of infection (noticeable spots) on the first leaf were observed up to 6 days post submergence. Second, seedlings at the same stage were inoculated by placing the teliospore impregnated agar around the stem in pots, moved to a greenhouse and grown to full panicle development stage. Third, seedings were inoculated via syringe inoculation in the greenhouse. Although soil inoculated seedlings grown in the greenhouse did not result in systemic infection as determined by lack of symptoms at panicle exsertion, 88.9% of tested cultivars showed systemic infections when syringe inoculated in the greenhouse. Inoculation of seedlings maintained under water led to broad range of noticeable spots that are assumed to be potential infection sites based on a previous study. In addition, seedling inoculation led to slightly upregulated expression of chitinase and PR10, genes that are associated with defense in aerial parts of plants. [ABSTRACT FROM AUTHOR]

False smut of rice caused by Ustilaginoidea virens (Cooke) Takahashi, is an emerging disease of rice. A field experiment was conducted during two consecutive kharif seasons (2019-20 and 2020-21) to find out the influence of weather parameters on disease development. The data so obtained was analyzed through correlation and regression individually and by pooling. The first symptom of false smut was appeared on 47th SMW where disease severity was 4.49 per cent (2019-20) and 0.44 per cent (2020-21) and reached the highest level of 44.49, 48.78 per cent and 23.59, 25.04 per cent on 51st and 52nd SMW, respectively. Correlation study between disease severity and weather parameters indicated that weather parameters played important role in development of false smut of rice. Moreover, maximum relative humidity, minimum relative humidity and minimum temperature found to play a dominant role in the disease development. Stepwise regression, R value i.e., 0.79, 0.91 and 0.75 per cent and coefficient of determination, R2 value i.e., 61.70, 83.50 and 56.20 per cent were found high during 2019-20, 2020-21 and pooled data of two years, respectively. These high R-value indicated strong association between disease severity and weather parameters. [ABSTRACT FROM AUTHOR]

'CLM04' (Reg. no. CV‐155, PI 692953) is a high‐yielding, early‐maturing, and short‐stature Clearfield (BASF Corporation) medium‐grain rice (Oryza sativa L.) cultivar developed by the University of Arkansas Rice Research and Extension Center (RREC) in Stuttgart, AR, and approved for release by the University of Arkansas System Division of Agriculture Experimental Station in January 2019. It was derived from the cross 'RU1202168'/'Jupiter' made at RREC in spring 2013 and advanced as F4 bulk of a single progeny row 14P54617 at the RREC in summer 2014. From 2015 to 2019, CLM04 was evaluated in 51 statewide and regional replicated trials. The Clearfield medium‐grain cultivar 'CL272' as well as conventional medium‐grain cultivars 'Jupiter' and 'Titan' served as checks. Grain yield of CLM04 was 9.58 Mg ha−1 compared with 9.17 Mg ha−1 for CL272, 9.97 Mg ha−1 for Jupiter, and 10.15 Mg ha−1 for Titan. CLM04 has an average height of 107 cm which is 10, 9, and 5 cm taller than Jupiter, Titan, and CL272, respectively. CLM04 reached 50% heading 5 d later than Titan at 87 d from emergence, which is similar to CL272 and Jupiter, which mature at 85 and 87 d, respectively. CLM04 is moderately resistant to leaf blast and susceptible to sheath blight, bacterial panicle blight, kernel smut, and false smut. Core Ideas: CLM04 is a Clearfield medium‐grain cultivar developed by the University of Arkansas.CLM04 is a high‐yielding, early‐maturing, and short‐stature cultivar.CLM04 is adapted to rice growing conditions throughout Arkansas and the mid‐South. [ABSTRACT FROM AUTHOR]

The biotrophic fungus Ustilago maydis secretes a plethora of uncharacterized effector proteins and causes smut disease in maize. Among the effector genes that are up-regulated during the biotrophic growth in maize, we identified vp1 (virulence promoting 1), which has an expression that was up-regulated and maintained at a high level throughout the life cycle of the fungus. We characterized Vp1 by applying in silico analysis, reverse genetics, phenotypic assessment, microscopy, and protein localization and provided a fundamental understanding of the Vp1 protein in U. maydis. The reduction in fungal virulence and colonization in the vp1 mutant suggests the virulence-promoting function of Vp1. The deletion studies on the NLS (nuclear localization signal) sequence and the protein localization study revealed that the C-terminus of Vp1 is processed after secretion in plant apoplast and could localize to the plant nucleus. The Ustilago hordei ortholog UhVp1 lacks NLS localized in the plant cytoplasm, suggesting that the orthologs might have a distinct subcellular localization. Further complementation studies of the Vp1 orthologs in related smut fungi revealed that none of them could complement the virulence function of U. maydis Vp1, suggesting that UmVp1 could acquire a specialized function via sequence divergence. [ABSTRACT FROM AUTHOR]

Background. The primary task of plant breeding is to develop and introduce into production two-row mid-season barley cultivars for feed and food purposes, capable of generating a high and high-quality grain yield. The purpose of the study is to characterize the new two-row fodder spring barley cultivar ‘Omsky 101’ (bred at Omsk Agrarian Scientific Center) according to its grain quality, yield and resistance to a set of diseases.Materials and methods. The experimental part of the work was carried out from 2013 through 2018 on the experimental fields of Omsk Agrarian Scientific Center, located in the southern forest-steppe and steppe zones. The area of the plot was 10 m2; there were 4 replications. The seeding rate was 4 million viable seeds per 1 ha. Agricultural practice in the experiment was conventional for the West Siberian region. Mathematical data processing complied with B. A. Dospekhov’s guidelines.Results. In terms of productivity, the new promising cv. ‘Omsky 101’ is a high-yielding variety; on average, over the period of research, its yield significantly exceeded the level of the reference cv. ‘Omsky 95’ both in the southern forest-steppe zone (+0.55 t/ha) and in the steppe zone (+0.38 t/ha). The increase over cv. ‘Omsky 100’ was 0.29 and 0.59 t/ha when sown over autumn plowing and fallow, respectively. When compared with the reference ‘Omsky 95’, ‘Omsky 101’ showed a gain in the weight of 1000 grains (+5.3 g), grain unit weight (+44.0 g/l), and grain uniformity (+12.4%). Also, when compared with both the reference and ‘Omsky 100’, there was an increased content of protein (+1.0 and +0.9%, respectively) and starch (+1.3 and +1.5%, respectively) in grain. During the period of study, according to the maximum damage scores with various smut species, ‘Omsky 101’ showed low rates of susceptibility to false loose smut (3.5% on average) and covered smut (5.0%), which is lower than the reference and level with cv. ‘Omsky 100’. Loose smut virulence rate was medium (23.1%), which is level with the reference but exceeds ‘Omsky 100’. Conclusion. The new promising cultivar ‘Omsky 101’ is high-yielding, of high quality, and resistant to smut species. The cultivar has been submitted to State Variety Trials in the Ural (9), West Siberian (10) and East Siberian (11) regions.

Sugar cane smut (Sporisorium scitamineum) interactions have been traditionally considered from the plant’s point of view: How can resistant sugar cane plants defend themselves against smut disease? Resistant plants induce several defensive mechanisms that oppose fungal attacks. Herein, an overall view of Sporisorium scitamineum’s mechanisms of infection and the defense mechanisms of plants are presented. Quorum sensing effects and a continuous reorganization of cytoskeletal components, where actin, myosin, and microtubules are required to work together, seem to be some of the keys to a successful attack. [ABSTRACT FROM AUTHOR]

Loose smut disease is a fungal infection, commonly found in Wheat, Oats, and Barley. The bibliometric analysis had been conducted to understand the active authors, organizations, journals, and countries involved in the research domain of “Loose smut”. All published articles related to “Loose smut” from “Scopus”, were analyzed using the VOS viewer to develop analysis tables and visualization maps. This article had set the objective to consolidate the scientific literature regarding the “Loose smut” and also to find out the trends related to the same. The most active journals in this research domain are the Canadian Journal of Plant Science, Canadian Journal of Plant and Genome. The most active country is Canada and Kenya. Agriculture and Agri-Food Canada) of Canada is the most active research institute in this research domain. The most active authors related to Loose smut disease are Menzies J.G., Knox R.E., and Swart W.J. [ABSTRACT FROM AUTHOR]

Covered smut is a fungal disease caused by “Ustilago hordei”. The bibliometric analysis had been conducted to understand the active authors, organizations, journals, and countries involved in the research domain of “Covered smut”. All published articles related to “Covered smut” from “Scopus”, were analyzed using the VOS viewer to develop analysis tables and visualization maps. This article had set the objective to consolidate the scientific literature regarding the “Covered smut” and also to find out the trends related to the same. The most active journals in this research domain are the Canadian Journal of Plant Science, Canadian Journal of Plant, and PLoS Pathogens. The most active country is Canada and followed by the USA. Agriculture and Agri- Food Canada of Canada is the most active research institute in this research domain. The most active authors who had made valuable contributions related to Covered smut disease are Chong J. and Doehlemann G. [ABSTRACT FROM AUTHOR]

Sugarcane smut, caused by Sporisorium scitamineum, is one of the most important sugarcane diseases in Japan. Wild sugarcane, Saccharum spontaneum, is known to be a key breeding material to obtain high-yielding clones. In this study, we sought to identify Japanese wild sugarcane accessions with high resistance to smut. Thirty wild sugarcanes and three sugarcane cultivars were tested by the pinprick method. The results of the inoculation tests aided in identifying wild sugarcanes with high resistance to smut disease, namely JW90, Iriomote8, and Iriomote15. After screening the germplasm, progeny distribution of smut resistance from the inoculation test and dry matter productivity in the smut disease-free field were compared. The highly resistant wild sugarcane accession had a much better impact on progeny distribution of smut resistance compared with the susceptible accession. No relationship was found between smut resistance and dry matter productivity in both populations. [ABSTRACT FROM AUTHOR]

Bacterial endophytic ubiquitously colonize the internal tissues of the plant. The purpose of this study was to isolate and identify the endophytic bacteria from sugarcane stalks which have antagonistic activity against Sporisorium scitamineum, the causal pathogen of sugarcane smut disease, and to study their activity to produce some secondary metabolites i.e. enzymes and growth-promoters. Sugarcane samples were collected from five governorates in Upper-Egypt namely, Giza, Beni-Suef, Sohag, Qena, and Luxor. A total of 240 isolates of endophytic bacteria were isolated from 160 samples of healthy sugarcane stalks (variety GT-54-9). Isolated endophytes were screened for its antagonistic activity against S. scitamineum, in vitro, using dual culture method. Only, 62 isolates showed different degrees of antagonistic activity. Ten isolates of endophytic bacteria were selected to study their potential to produce enzymes (chitinase, β 1,3 glucanase, phenylalanine ammonia lyase) and growth-promoters (siderophores, indole acetic acid (IAA), salicylic acid (SA)). These isolates were pre-identified using the morphological and physiological properties according to Bergy's manual as Pseudomonas sp., Serratia sp., Enterobacteria sp., Herbaspirillium sp., Gluconacetobacter sp. Anabaenopsis sp. and Azospirillumsp. All endophetic bacteria produced β 1,3gluconase and indole acetic acid (IAA), while Pseudomonas sp. produced salicylic acid and phenylalanine ammonia lyase, Anabaenopsis sp. produced phenylalanine ammonia lyase, Gluconacetobacter sp. produced chitinase and Herbaspirillium sp. produced siderophore. Meanwhile, isolates of Anabaenopsis sp. and Pseudomonas sp. were the most effective to produce β 1,3glucanase and indole acetic acid compared with other entophytic bacteria. [ABSTRACT FROM AUTHOR]

This research investigated whether anther smut disease caused by Microbotryum violaceum agg. on Silene baccifera in Europe is caused by a host‐specific lineage, or if it represents a host shift of the pathogen from a related species. Characterization of ITS sequences of anther smut from S. baccifera confirmed their strong similarity to the pathogen endemic on Silene latifolia. Cross‐inoculation studies showed that S. baccifera was susceptible to anther smut isolates from S. latifolia, S. dioica and S. vulgaris; conversely isolates from S. baccifera could cause disease on S. latifolia. In an experimental field study, spore transmission from diseased S. latifolia to healthy S. baccifera was rare relative to intraspecific transmission within S. latifolia. The distribution of anther smut in natural populations based on herbarium specimens indicated that disease occurrence on S. baccifera was very sporadic. These findings strongly suggest that anther smut disease on S. baccifera in Europe is usually a temporary host shift from the self‐sustaining populations of Microbotryum on other species. [ABSTRACT FROM AUTHOR]

This paper examines the rise and fall of Carl Linnaeus's ideas on living contagion, focusing on his work with plant smut diseases. Early in his career, Linnaeus named a plant altered by anther-smut disease as a separate species, but then, probably realizing it was a diseased specimen, demoted it to a variety. He later drew direct parallels between minute insects attacking plants and infectious diseases in humans, but did not yet draw an analogy to smut diseases. After Otto von Münchhausen had sent Linnaeus the first instalment of his book Der Hausvater (1764), Linnaeus realized smuts were contagious. He carried out his own investigations that appeared to confirm Münchhausen's conclusion that smut spores germinated to produce living and mobile animalcules. This cemented Linnaeus's view that animalcules caused contagion in human diseases, a view which he expressed forcefully, urging further studies. However, his results were questioned and discounted by others, especially John Ellis. An analysis of correspondence between Linnaeus and other microscopists shows that it is likely Linnaeus did actually see "animalcules" emerging from cereal grains. He was unaware that smut-like symptoms in wheat could also be caused by seed-gall nematodes in the genus Anguina. Linnaeus himself came to doubt the connection between fungi and contagion, and did not pursue these studies further. The presumption that Linnaeus was fanciful in his observations of animalcules may partly explain why his views had only a tangential impact on the germ-theory of disease, and why his insights remain unappreciated to this day. [ABSTRACT FROM AUTHOR]

Ustilago maydis, causal agent of smut disease in maize, induces significant yield losses by forming colossal galls (tumours) on cobs. Since infection process of U. maydis is parallel with natural pollination of maize, an interaction between maize pollination and the smut fungus is probable. To reveal this interaction perceptibly, a 2-year field study was carried out in Antalya province of Turkey. As host plants, 8-maize-cultivars belonging to different maize variety groups [dent (Ada-523, Pioneer-3394 and Side), flint (Karaçay and Karadeniz Yıldızı), sweet (Merit and Vega) and popcorn (Antcin-98)] were used in the experiment. Inoculations were performed by injecting inoculum into cob silks in pre- and post-pollination periods in plots. In addition, control plots were set up for each treatment. In conclusion, average disease severity, incidence and yield losses of all the maize cultivars in pre-pollination inoculations (PrePI) were 3.8, 20.7 and 45.5%, whereas in post-pollination (PostPI) inoculations, they were 0.9, 15.7 and 35.9%, respectively. It was found that in both years, disease values of the PrePI were higher than those of the PostPI. This study suggested that pollination period of maize is an important factor affecting U. maydis infection in cobs and accordingly yield losses. [ABSTRACT FROM AUTHOR]

Ustilaginoidea virens is an important fungus that causes rice false smut disease. This disease significantly reduces both grain yield and quality. Various methods have been developed for the detection of U. virens but most of these methods need sophisticated equipment such as a thermal cycler. Here, we present a loop-mediated isothermal amplification (LAMP) assay for the specific detection of U. virens. This assay used a specific region of the UvG-β1 gene (212-bp region) to design six LAMP primers. The LAMP assay was optimized by the combination of rapidity, simplicity, and high sensitivity for the detection of about 1 pg of target genomic DNA in the reaction whereas, with polymerase chain reaction (PCR), there was no amplification of DNA with concentrations less than 1 ng. Among the genomic DNA of 22 fungus species and two strains of U. virens, only the tube containing the DNA of U. virens changed to yellowish green with SYBR Green I. The color change was indicative of DNA amplification. No DNA was amplified from either the other 22 fungus species or the negative control. Moreover, 20 spikelets and 22 rice seed samples were used for the detection of rice false smut via LAMP. The results were comparable with conventional PCR. We conclude that gene UvG-β1 coupled with LAMP assay, can be used for the detection and identification of U. virens gene via LAMP. [ABSTRACT FROM AUTHOR]

Ustilago maydis (DC) Corda, the causal agent of maize smut disease, can form enormous galls on cobs and cause significant yield losses under favorable conditions. In addition to yield losses, U. maydis may have an influence on the kernel quality in smutted cobs. The aim of this study was to determine presence of mycoflora on the cobs infected by U. maydis. A 2-year field experiment was conducted in Antalya Province. In the study, some maize cultivars belonging to various maize variety groups including dent corn, flint corn, sweet corn and popcorn were used as host plants. Inoculations were performed by injecting inoculum into ear silk of each cob of the plants in inoculated plots. For each treatment, control plots were also set up. When the kernels of cobs in control plots were mature enough to harvest, kernel samples in inoculated plots were taken from smutted cobs and investigated in terms of fungal flora. A total of 6 genera (Paecilomyces, Aspergillus, Penicillium, Acremonium, Fusarium, Rhizopus) were detected from the kernels in the smutted cobs. However, frequently isolated species were Aspergillus fumigatus, A. niger, A. parasiticus (A. flavus), Paecilomyces lilacinus, Penicillium citrinum, Fusarium solani, F. oxysporum and Rhizopus stolonifer. The most frequently isolated genus was Aspergillus (31.4%), while the lowest one was Penicillium (6.4%). The study showed that U. maydis may affect kernel quality of maize by harboring some fungal microorganisms in smutted cobs. [ABSTRACT FROM AUTHOR]

Smut is the most important disease of sugarcane in Iran, and most of the plant growing areas in the world. The most effective method of disease management, is identification and cultivation of resistant varieties. The aim of this study was to investigate changes in the level of phenolic compounds in resistant and susceptible cultivars to disease and detection phenolic compounds resistance index, to accelerate the identification of resistant cultivars. Two cultivars NCO-310 and CP78-1628, susceptible and resistant to the disease were selected, and with apical meristem and lateral buds culture method, their seedlings with four leaves were produced. Seedlings were inoculated with a suspension of a mixture of two compatible mating type of pathogen. Stem of plants were sampled at 0-120 hour post-inoculation. Soluble and cell-wall binding phenolic acids were extracted from samples, and presence and concentration of phenolic acids p-coumaric , ferulic, p-hydroxybenzoic and syringic acids were detected and determined by high performance liquid chromatography (HPLC) method. Comparison the data obtained from HPLC device showed only titer of cell wall-bound phenolic acids ferulic and syringic showed enhancement, in the resistant cultivar, this reflects the role of these phenolic acids in the resistance reaction. Thus, these phenolic acids can be considered as an indicator of resistance, and in this way quickly identify resistant cultivars and management disease. [ABSTRACT FROM AUTHOR]

Smut caused by biotrophic fungus Sporisorium scitamineum is a major disease of cultivated sugarcane that can cause considerable yield losses. It has been suggested in literature that there are at least two types of resistance mechanisms in sugarcane plants: an external resistance, due to chemical or physical barriers in the sugarcane bud, and an internal resistance governed by the interaction of plant and fungus within the plant tissue. Detailed molecular studies interrogating these two different resistance mechanisms in sugarcane are scarce. Here, we use light microscopy and global expression profiling with RNA-seq to investigate these mechanisms in sugarcane cultivar CP74-2005, a cultivar that possibly possesses both internal and external defence mechanisms. A total of 861 differentially expressed genes (DEGs) were identified in a comparison between infected and non-infected buds at 48 hours post-inoculation (hpi), with 457 (53%) genes successfully annotated using BLAST2GO software. This includes genes involved in the phenylpropanoid pathway, cell wall biosynthesis, plant hormone signal transduction and disease resistance genes. Finally, the expression of 13 DEGs with putative roles in S. scitamineum resistance were confirmed by quantitative real-time reverse transcription PCR (qRT-PCR) analysis, and the results were consistent with the RNA-seq data. These results highlight that the early sugarcane response to S. scitamineum infection is complex and many of the disease response genes are attenuated in sugarcane cultivar CP74-2005, while others, like genes involved in the phenylpropanoid pathway, are induced. This may point to the role of the different disease resistance mechanisms that operate in cultivars such as CP74-2005, whereby the early response is dominated by external mechanisms and then as the infection progresses, the internal mechanisms are switched on. Identification of genes underlying resistance in sugarcane will increase our knowledge of the sugarcane-S. scitamineum interaction and facilitate the introgression of new resistance genes into commercial sugarcane cultivars. [ABSTRACT FROM AUTHOR]

False smut (Ustilaginoidea virens (Cooke) Takahashi) of rice is an emerging disease and a potential threat to rice growers in different countries due to reduction in yield, quality and production of mycotoxins. Development and cultivation of resistant varieties is desirable approach for its management. Different inoculation techniques viz. spray inoculation, syringe inoculation and dusting method were evaluated for creating artificial epiphytotic conditions in susceptible variety PR116 under natural as well as artificially provided humidity conditions. Spray inoculation method produced more number of smut balls per plant (3.21) and per cent infected panicles (33.44%) followed by syringe inoculation (2.00 and 26.57%, respectively) and dusting method (0.33 and 6.67%, respectively). However, syringe inoculation method produced more spikelet sterility (14.82%) in rice panicles. More disease occurrence was reported in plants provided with artificial humidity after inoculations (51.12% infected panicles) than the plants grown under natural conditions (13.33% infected panicles). Late transplanted crop developed higher disease severity (18.17% infected panicles and 3.34 smut balls/plant) which might be attributed by slight decrease in temperature and increase in relative humidity conditions (up to 88% RH) at time of infection from boot to early flowering stage of the rice crop. [ABSTRACT FROM AUTHOR]

Identification of the "bean smut" reported in 1998 in abstracts from two conferences was later disseminated by a Plant Disease Note; citations in books, papers, and blogs; and in several official sites, including databases curated by the United States Department of Agriculture and Embrapa- Brazil. After seeing the illustration of the syndrome in 2002, the need became clear for a review of the so-called bean smut. Field collections indicated that it is common in no-till bean and soybean farming in Brazil. Our studies revealed that the "bean smut" attributed to Ustilago sp. or "Ustilago phaseoli" and, later, to "Microbotryum phaseoli" is not a real smut but is Physarum cinereum (Physaraceae, Physarales, Myxomycetes), sporulating superficially on leaves, stems, and pods of dry bean and soybean. To unravel this imbroglio, we produced detailed morphological documentation supported by molecular treatment. This will correct the spread and further incorporation of an error in the literature based upon mistaken taxonomical work related to a plant-associated nonpathogenic organism. [ABSTRACT FROM AUTHOR]

The successful interaction between pathogen/parasite and host requires a delicate balance between fitness of the former and survival of the latter. To optimize fitness a parasite/pathogen must effectively create an environment conducive to reproductive success, while simultaneously avoiding or minimizing detrimental host defense response. The association between Microbotryum lychnidis-dioicae and its host Silene latifolia serves as an excellent model to examine such interactions. This fungus is part of a species complex that infects species of the Caryophyllaceae, replacing pollen with the fungal spores. In the current study, transcriptome analyses of the fungus and its host were conducted during discrete stages of bud development so as to identify changes in fungal gene expression that lead to spore development and to identify changes associated with infection in the host plant. In contrast to early biotrophic phase stages of infection for the fungus, the latter stages involve tissue necrosis and in the case of infected female flowers, further changes in the developmental program in which the ovary aborts and a pseudoanther is produced. Transcriptome analysis via Illumina RNA sequencing revealed enrichment of fungal genes encoding small secreted proteins, with hallmarks of effectors and genes found to be relatively unique to the Microbotryum species complex. Host gene expression analyses also identified interesting sets of genes up-regulated, including those involving stress response, host defense response, and several agamous-like MADS-box genes (AGL61 and AGL80), predicted to interact and be involved in male gametophyte development. [ABSTRACT FROM AUTHOR]

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False smut of rice caused by Ustilaginoidea virens (Cooke), increasing concern in majority of rice growing areas around the world as epidemics have been reported lately. The fungus completely converts the grains into spore balls, unfit for consumption and seed production. With the increase in disease, yield loss and disease severity is accentuating. The QTLs responsible for the false smut resistance to be identified and consistent inheritability of these QTLs have to be evaluated using marker assisted selection. Due to heavy application of nitrogenous fertilizers the disease aggravates, proper management strategies needed to be framed to control the false smut disease. Progress in achieving the resistance varieties and management of false smut needs more emphasis. This review summarizes the present status in the screening of resistant varieties and management of false smut in rice. [ABSTRACT FROM AUTHOR]

The causal agent of flag smut of wheat is currently subject to strict quarantine regulations in many countries and is believed to have a wide host range on wild and cultivated grasses. This fungus has been classified as both Urocystis agropyri and Urocystis tritici. Urocystis agropyri was first described from Elymus repens in Germany and U. tritici was first described from Triticum vulgare (= T. aestivum). In 1953, G. W. Fischer placed U. tritici and a large number of other Urocystis species in synonymy with U. agropyri. The present study is the first attempt to clarify the taxonomy and phylogeny of flag smut pathogens of grasses using molecular analyses. Three loci, the internal transcribed spacer ( ITS) region of rDNA, the RNA polymerase II subunit 2 ( RPB2), and translation elongation factor ( TEF) protein-coding regions were used for phylogenetic reconstruction to determine the species boundaries of 24 Urocystis specimens from triticoid hosts. Results indicate that there are several distinct lineages of flag smut pathogens, including the causal agent of flag smut of wheat, which is supported as a separate species, U. tritici. Sequences from specimens on E. repens, which are retained as U. agropyri, grouped in a clade distinct from those on wheat and rye. The closest relatives of U. tritici were found to be U. hispanica from Aegilops and Urocystis sp. from Thinopyrum junceiforme and Elymus trachycaulis. Recognition that U. tritici is genetically distinct from U. agropyri sensu stricto will impact regulatory policy and facilitate the development of diagnostic tests. [ABSTRACT FROM AUTHOR]

The study was planned to standardize an efficient inoculation method for covered smut of barley (Hordeum vulgare L.) caused by Ustilago hordei (Pers.) Lagerheim. Among different methods of artificial inoculation tried, mechanical dehulling of barley seeds followed by inoculation by dipping in spore suspension for 30 minutes proved to be the best method for creating artificial epiphytotic with 82.28 and 21.86 per cent disease on plant and tiller basis, respectively. This method was followed in efficiency by inoculating seeds with spore and talcum powder mixture (1:3). There was 70.73 and 17.31 per cent infection on plant basis and tiller basis, respectively. Eighty three barley germplasm accessions comprising of 73 germplasm lines and 10 varieties were evaluated against covered smut disease. Among the 10 varieties, two viz. PL 419 and HBL 316 were found to be completely free from the disease, whereas three varieties i.e. SONU, PL 172 and PL 426 were found to be resistant. Likewise, three varieties i.e. HBL 113, HBL 391 and PL 807 showed moderately resistant reaction. Among 73 germplasm lines, 18 showed high level of resistance and were found free from the disease. Twenty one germplasm lines were found to be resistant, whereas twenty four showed moderate resistance against covered smut. [ABSTRACT FROM AUTHOR]

Ustilaginoidea virens is a fungal pathogen that causes the false smut disease in rice and reduces the yield and quantity of the grains. A nested polymerase chain reaction (PCR)-based assay was developed to detect U. virens using genes of U. virens as specific targets. Ninety-six candidate genes of U. virens were found through first-round homology screening against a local database comprising 46 genomes of fungi, bacteria, and plants, with a second-round comparison with the GenBank NR database to further identify genes unique to U. virens. Among 96 remaining candidate genes, 20 of them (GenBank accessions KY617806 to KY617825) were randomly selected for further testing and, eventually, six sets of nested PCR primers were developed after further sensitivity, specificity, and detection tests. All six sets could detect DNA of U. virens at as little as 1 to 10 fg/μl from field or lab samples. These primers may be used to detect infection by U. virens at early stages, for use in research toward mitigating disease spread, as well as for studying the ecology of U. virens. This study also serves to illustrate that a comparative genomics method may allow for selection and development of highly specific primers once draft or complete genomes are available. [ABSTRACT FROM AUTHOR]

Villosiclava virensis an ascomycete fungus (anamorph:Ustilaginoidea virens) recognized as one of the most economically important pathogens on rice in China that causes false smut disease. In our study, theV. virens cyp51gene encoding the target protein for fungicide resistant to tebuconazole was cloned. Sequencing showed that fungal mutant strains resistant to tebuconazole harboured the T409C mutation incyp51. A simple and rapid allele-specific PCR assay was developed to detect the T409C mutation. Among the isolates tested, a unique 391-bp fragment was amplified from resistant mutant strains with primer pair Uv137F1/Uv137DR, whereas no product was amplified from all sensitive isolates. Our study demonstrated that this allele-specific PCR assay is a rapid, simple and reliable method for identification ofV. virensmutants resistant to tebuconazole. [ABSTRACT FROM PUBLISHER]

Shakarganj Sugar Research Institute (SSRI) of Shakarganj Mills Limited (SML) Jhang, is unique in private sector as it aims to produce new sugarcane varieties. The institute possesses an honour to evolve five new sugarcane varieties SPSG-26, SPSG-394, KHAN BAHADAR NSG-555 and NSG-311. The data available under consideration is from these varieties that are in process of development. Twenty clones had indentified against diseases and pests. All clones were moderately resistant (MR) and resistant (R) against red rot. In case of rust disease, fifteen clones were found resistant (R). While other diseases pokha boeng nine clones, smut eighteen clones and against red rot all clones were resistant. When comparison was done against insect pest resistance, SLSG-18 clone immune to root borer, SLSG-3, SLSG-6 immune to stem borer and SLSG-6, SLSG-18 immune to gurdaspur borer. No clone found immune and highly resistant against top borer. [ABSTRACT FROM AUTHOR]

Anther smuts on Silene acaulis and S. uniflora from the Outer Hebrides, Scotland, UK), are analysed using morphological and molecular techniques, and found to represent Microbotryum silenes-acaulis and M. silenes-inflatae, respectively. This is the first identification of caryophyllaceous anther smuts in the Outer Hebrides according to modern species concepts and the first report of Microbotryum silenes-acaulis confirmed by molecular analysis from the British Isles. Additionally, the genetic structure of Microbotryum silenesacaulis, based on all currently available ITS sequences, is analysed and discussed. Seven ITS genotypes are determined for Microbotryum silenes-acaulis, including three genotypes in North America and four genotypes in Europe. Compared to European accessions, all North American accessions share specific nucleotides and are genetically divergent. [ABSTRACT FROM AUTHOR]

Sugarcane smut is a fungal disease caused by Sporisorium scitamineum, which can cause severe economic losses in sugarcane industry. The infection depends on the mating of bipolar sporida to form a dikaryon and develops into hyphae to penetrate the meristematic tissue of sugarcane. In this study, we set to isolate bacterial strains capable of blocking the fungal mating and evaluate their potential in control of sugarcane smut disease. A bacterial isolate ST4 from rhizosphere displayed potent inhibitory activity against the mating of S. scitamineum bipolar sporida and was selected for further study. Phylogenetic analyses and biochemical characterization showed that the isolate was most similar to Pseudomonas guariconensis. Methanol extracts from minimum and potato dextrose agar (PDA) agar medium, on which strain ST4 has grown, showed strong inhibitory activity on the sexual mating of S. scitamineum sporida, without killing the haploid cells MAT-1 or MAT-2. Further analysis showed that only glucose, but not sucrose, maltose, and fructose, could support strain ST4 to produce antagonistic chemicals. Consistent with the above findings, greenhouse trials showed that addition of 2% glucose to the bacterial inoculum significantly increased the strain ST4 biocontrol efficiency against sugarcane smut disease by 77% than the inoculum without glucose. The results from this study depict a new strategy to screen for biocontrol agents for control and prevention of the sugarcane smut disease. [ABSTRACT FROM AUTHOR]

A 300-bp RAPD-derived Sequence Characterized Amplified Region (SCAR) marker linked with resistance to sugarcane smut disease was developed. Bulked segregant analysis and RAPD were conducted using 480 random decamers in the initial screening of 12 sugarcane cultivars (two completely smut resistant, two completely smut susceptible, four moderately smut resistant, and four moderately smut susceptible). Eighty-four of these primers proved to be polymorphic while only one (B17) produced a reproducible polymorphic fragment, which appeared to co-segregate in repulsion with sugarcane smut resistance. A 300-bp B1SM-F/B1SM-R SCAR marker was designed based on the sequence alignment of the B17 products. Testing of this SCAR marker on these12 cultivars confirmed its specificity on two completely and four partially resistant cultivars. Further screening of this SCAR marker on seven additional sugarcane cultivars of Pakistan verified the earlier findings. Therefore, it was deduced that the B1SM-F/B1SM-R SCAR marker is linked with smut resistance trait in sugarcane. NCBI blast of the SCAR marker sequence showed no homology to any of the earlier identified sequences in GenBank. The newly discovered B1SM-F/B1SM-R SCAR marker for sugarcane smut resistance will facilitate sugarcane breeding programs since it can be used for marker-assisted selection in sugarcane. [ABSTRACT FROM AUTHOR]

Main Conclusion : Smut pathogen induced an early modulation of the production and scavenging of reactive oxygen species during defence responses in resistant sugarcane that coincided with the developmental stages of fungal growth. Sporisorium scitamineum is the causal agent of sugarcane smut disease. In this study, we characterized sugarcane reactive oxygen species (ROS) metabolism in response to the pathogen in smut-resistant and -susceptible genotypes. Sporisorium scitamineum teliospore germination and appressorium formation coincided with HO accumulation in resistant plants. The superoxide dismutase (SOD) activity was not responsive in any of the genotypes; however, a higher number of isoenzymes were detected in resistant plants. In addition, related to resistance were lipid peroxidation, a decrease in catalase (CAT), and an increase in glutathione S-transferase (GST) activities and an earlier transcript accumulation of ROS marker genes ( CAT3, CATA, CATB, GST31, GSTt3, and peroxidase 5- like). Furthermore, based on proteomic data, we suggested that the source of the increased hydrogen peroxide (HO) may be due to a protein of the class III peroxidase, which was inhibited in the susceptible genotype. HO is sensed and probably transduced through overlapping systems related to ascorbate-glutathione and thioredoxin to influence signalling pathways, as revealed by the presence of thioredoxin h-type, ascorbate peroxidase, and guanine nucleotide-binding proteins in the infected resistant plants. Altogether, our data depicted the balance of the oxidative burst and antioxidant enzyme activity in the outcome of this interaction. [ABSTRACT FROM AUTHOR]

Study was aimed to access genetic relationships and response for whip smut among 103 sugarcane lines/varieties through DNA genotyping. Touchdown PCR amplification based genotyping of four tailed (M-13) and 26 (FAM-labelled) SSRs markers was performed on Licor 4300 DNA Analyzer and ABI Genetic Analyzer 3730, respectively. Using different softwares, 314 alleles were scored, averaging 10.46 alleles per marker. Polymorphism information content (PIC) values ranged from 0.67 to 0.93. DNAMAN generated homology tree revealed 66-88% genetic similarity among the studied sugarcane lines which indicated their narrow genetic base. The markers mSSCIR-19 and mSSCIR-43 were able to distinguish between all the sugarcane lines resistant and susceptible to whip smut. The grouping of sugarcane lines showing different responses to whip smut within the same cluster indicates that many genes with little effects are involved in smut resistance. The results may help sugarcane breeders in variety identification and designing crosses for developing whip smut resistant cultivars. [ABSTRACT FROM AUTHOR]

Ustilago tritici, a seed borne pathogen, remains dormant in seed embryo and causes loose smut disease. The present study was conducted to evaluate two inoculation methods i.e., dip inoculation and syringe inoculation to find out the better method for efficient and reproducible assessment of disease severity, disease incidence and screening of resistant wheat germplasm. Syringe inoculation was found to be better for the inoculation of heads with higher disease incidence than dip inoculation method. Twenty-seven lines were tested for their resistance against loose smut. Two lines were moderately resistant, nineteen lines susceptible and three lines were highly susceptible. Environmental conditions play an integral role in the development of loose smut disease. The relationship of temperature, humidity and rainfall with loose smut development was studied. An average temperature of 23-27 °C, relative humidity 60-90% and rainfall 0.02-1 mm rainfall were statistically most conducive for disease development. The correlation of environmental factors significantly influenced the disease development. [ABSTRACT FROM AUTHOR]

Background and aims: Smut disease is a severe limiting factor in foxtail millet production, caused by the Ustilago crameri fungus. The aim of this study is to characterize specific bacterial populations that might contribute to smut disease suppression. Methods: Rhizosphere bacterial community compositions of three foxtail millet cultivars differing in smut disease resistance were compared using high throughput Illumina sequencing. Results: As a disease-resistant cultivar, Jigu20 showed the lowest disease incidence (0.7 %) after Ustilago crameri inoculation, compared with 14.8 % and 62.5 % for Jingu21 and Changnong35, respectively. Under the Ustilago crameri-inoculation condition, higher bacterial diversity was present in the rhizosphere of Jigu20 (I.Ji20) than in other two soil samples (I.Jin21 and I.Chang35). The same trend was observed in enzyme activities of phosphatase, catalase, and polyphenol oxidase. Compared to I.Jin21 and I.Chang35, I.Ji20 harbored higher abundance of Actinobacteria, while lower abundance of Bacteroidetes and Firmicutes. At the genus level, the hierarchical cluster of I.Ji20 was clearly separated from I.Jin21 and I.Chang35. Pearson's correlation analysis showed that the abundance of Bradyrhizobium and Streptomyces was negatively correlated with smut disease incidence ( P < 0.05). Conclusions: Different smut resistant cultivars occupied different rhizosphere bacterial communities, and smut disease suppression might be correlated with high bacterial diversity. [ABSTRACT FROM AUTHOR]

Villosiclava virens is the causal pathogen of rice false smut (RFS) disease. RFS is an emerging panicle disease, concerning rice production worldwide. However, the biology and pathogenicity of V. virens are still not well-understood. In this study, we investigated the sugar preference of V. virens and the underlying mechanism on how the favored sugar promoted the fungal growth. The results demonstrated that V. virens preferentially utilized stachyose over sucrose that is previously reported to be the best carbon source for V. virens . Stachyose could promote conidia germination, hyphae elongation and mycelium growth of V. virens . Transcriptome and qRT-PCR analyses showed that genes involved in transporting carbohydrate, amino acid, inorganic ion and secondary metabolites were mostly up-regulated by stachyose than by sucrose. Moreover, Uv8b_6977 encoding a putative major facilitator superfamily (MFS) transporter was highly and specifically induced by stachyose, indicating that it may be a stachyose transporter. Expression levels of several stachyose-inducible MFS genes were also highly induced in V. virens -infected rice spikelets especially when early false smut balls appeared, implicating that these genes may play important roles in the formation of false smut balls. Collectively, this work identifies stachyose as a preferential carbon source for V. virens , and provides gene candidates for investigation of the sugar utilization mechanism of V. virens . [ABSTRACT FROM AUTHOR]

Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes false smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a false smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the false smut ball. This profile provides a general overview of the rice false smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely false smut balls. When maturing, the false smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the false smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces false smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of false smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice false smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: [ABSTRACT FROM AUTHOR]

Sugarcane smut disease is caused by the biotrophic fungus Sporisorium scitamineum. The disease is characterized by the development of a whip-like structure from the primary meristems, where billions of teliospores are produced. Sugarcane smut also causes tillering and low sucrose and high fiber contents, reducing cane productivity. We investigated the biological events contributing to disease symptoms in a smut intermediate-resistant sugarcane genotype by examining the transcriptional profiles (RNAseq) shortly after inoculating the plants and immediately after whip emission. The overall picture of disease progression suggests that premature transcriptional reprogramming of the shoot meristem functions continues until the emergence of the whip. The guidance of this altered pattern is potentially primarily related to auxin mobilization in addition to the involvement of other hormonal imbalances. The consequences associated with whip emission are the modulation of typical meristematic functions toward reproductive organ differentiation, requiring strong changes in carbon partitioning and energy production. These changes include the overexpression of genes coding for invertases and trehalose-6P synthase, as well as other enzymes from key metabolic pathways, such as from lignin biosynthesis. This is the first report describing changes in the transcriptional profiles following whip development, providing a hypothetical model and candidate genes to further study sugarcane smut disease progression. [ABSTRACT FROM AUTHOR]

Broomcorn millet ( Panicum miliaceum L.) is one of the most important minor grain crops in China. Head smut caused by Sporisorium destruens is a serious threat to broomcorn millet production. However, there is no information on the genetic diversity and virulence variation of S. destruens in China. To address this, a total of 51 S. destruens isolates were collected from broomcorn millet growing areas in China and characterized in genetic diversity with RAPD markers and 16 isolates representing different geographic origins and genotypes were tested in virulence. The Unweighted Pair Group Method with Arithmetic averages (UPGMA) dendrogram showed that the 51 isolates were divided into three lineages at an average similarity of 0.7022. There was no significant correlation between genotypes and geographic origins of the isolates. To determine the virulence variation of S. destruens isolates, a three-year resistance evaluation for 280 accessions was conducted and the results showed that the numbers of immune, highly resistant, resistant, susceptible and highly susceptible accessions were 8, 7, 108, 152 and 5, respectively. Ten accessions were selected as potential differential hosts. In virulence test, the 16 isolates tested were separated into three pathotypes and implied a virulence differentiation. This study demonstrated that S. destruens isolates had a moderate genetic diversity and a certain degree of virulence variation. Eight accessions were identified to be immune to S. destruens which were not previously discovered in China. The paper will provide a basis of knowledge for resistance breeding to broomcorn millet head smut. [ABSTRACT FROM AUTHOR]

Sugarcane smut disease, caused by Sporisorium scitamineum, significantly decreases yield and use of resistant cultivars is the most cost-effective measure for disease control. Current field testing methods for identification of smut resistance are time-consuming and hindered by environmental variability. Our goal was to develop an efficient and reliable resistance identification technique that is rapid, performed in a controlled environment, and stable. Nine sugarcane cultivars with different phenotypic resistance levels were selected. TaqMan quantitative real-time polymerase chain reaction analysis was performed to measure copy number changes of smut pathogen in sugarcane buds at 0-7 days after needle puncture inoculation. There was a positive correlation between time after inoculation and the amount of smut pathogen in the sugarcane bud. This reached a peak value on 7 days, and the copy number of S. scitamineum increased in the following order: YZ03-258, FN40, YZ01-1413, GT02-467, ROC22, YT96-86, YZ03- 103, FN39, LC05-136. After smut pathogen inoculation, differences in the physiological and biochemical indices of the nine cultivars were observed. Peroxidase, ascorbate peroxidase, catalase, superoxide dismutase, β-1,3-glucanase, and malondialdehyde were grouped into three main components, and the cumulative contribution rate was 80.177%, revealing that these are useful physiological and biochemical indicators of smut resistance. Subordinate function analysis indicated that the levels of smut resistance of the nine genotypes were (high to low): YZ03-258, FN40, YZ01-1413, GT02-467, ROC22, YZ03-103, YT96-86, FN39, LC05-136, which is similar to the results from copy number determination of smut pathogens. The results suggest that after artificial needle inoculation, rapid identification of physiological resistance to sugarcane smut was achieved based on copy number increases in the sugarcane smut pathogen and the physiological and biochemical changes in sugarcane bud during the early phase of infection. [ABSTRACT FROM AUTHOR]

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Smut disease caused by Sporisorium scitamineum is one of the most destructive sugarcane diseases worldwide. The pathogen spreads primarily through infected sugarcane setts, and hence, the use of disease-free planting materials is essential for preventing disease development in the field. In this study, a species-specific loop-mediated isothermal amplification ( LAMP) assay was developed for rapid and accurate detection of S. scitamineum. Based on the differences in internal transcribed spacer ( ITS) sequences of S. scitamineum, a set of four species-specific primers, F3, B3, FIP and BIP, were designed by using a panel of fungal and bacterial species as controls. After optimization of the reaction conditions, the detection limit of LAMP assay was about 2 fg of the S. scitamineum genomic DNA in 25 µL reaction solution, 100-fold lower than that of conventional polymerase chain reaction. The assay showed high specificity to discriminate all S. scitamineum isolates from nine other fungal and bacterial pathogens. The LAMP assay also detected smut infection from young sugarcane leaves with no visible smut-disease symptoms. The findings from this study provide a simple, highly sensitive, rapid and reliable technique for early detection of S. scitamineum, which may be useful for sugarcane quarantine and production of smut-free seedcanes. This is the first report of LAMP-based assay for the detection of S. scitamineum in sugarcane. [ABSTRACT FROM AUTHOR]