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Conidia of the common root rot pathogen, Cochliobolus sativus.
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Hosts Triticum aestivum L (wheat) and Hordeum vulgare L. (barley). Pathogen Cochliobolus sativus (Ito & Kurib.) Drechs. ex Dastur (teleomorph) and Bipolaris sorokiniana (Sacc.) Shoem. (anamorph) (= Helminthosporium sativum). Symptoms and Signs Initial symptoms of common root rot in either wheat or barley originate on young seedlings from inoculum c...
Contexts in source publication
Context 1
... anamorphic stage of C. sativus is easily isolated from symptomatic tissue placed under moist conditions. Conidia form quickly and are quite evident by their characteristic dark brown oval shape with thick cross walls (Fig 6). They usually appear within a few days at room temperature. ...
Context 2
... anamorphic or conidial stage of C. sativus is the one normally encountered. It is characterized by the presence of olive-brown conidiophores and large brown phragmoid (cross walls only in one direction) conidia borne laterally and terminally on the conidiophore (Fig. 6). The conidia of Pyrenophora sp. can be confused with those of C. sativus. The very thick walls of C. sativus conidia distinguish them from the very thin transparent walls of the conidia of Pyrenophora. Germination of C. sativus conidia occurs only from the polar (end) cells of the ...
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Samples of saved barley (Hordeum vulgare) seeds were collected at sowing and threshing time from mid- altitudes and highlands of southern Ethiopia in 2009, and were examined in the laboratory and field condition to determine the status of seed quality. The seed samples included farmers’ cultivar ‘Horsiso’ (two-rowed), ‘Nuro’ and ‘Melo’ (six-rowed)....
Citations
... It might be that clay loam soil has high water holding capacity which might have indirectly favored root rot-and wilt-causing pathogens whereas the sandy soil had low water holding capacity for a long time. This result disproves the fi nding of Mathre, et al. [27] who observed high common bean root rot disease incidence on sandy soil. The cropping system (sole and intercropped fi elds) was also recognized to affect the incidence and prevalence of common bean root rot. ...
Common bean root rot caused by fungal pathogens is an important disease affecting common bean crops in Ethiopia. Information on pathogen identification, characterization, and management options is lacking for the Ethiopian bean production system. This study aimed to assess the major causal fungal pathogens and their management through host resistance methods. Initially, a field survey was conducted in three districts in 2016. It was cored forty-five (45) common bean fields. In the mean time, disease samples were collected for laboratory analyses. Secondly, pathogen identification and characterization were done in Laboratory at Haramaya University, followed by a pathogenicity test. Thirdly, a genotypic reaction was done on twenty common bean varieties by using four fungal genera (F. oxysporum, S. rolfsii, M. phaseolina, and R. solani) as experimental materials that were arranged in (CRD) design with three replications. Out of forty-five (45) common bean fields assessed 33 farms exhibited the disease. In the pathogenicity test, all the isolates were found pathogenic and showed a significant (p < 0.05) difference. In addition, the analysis of variance also showed that out of the tested twenty varieties, some released varieties (Dandesu, Tinike, SER-125, Dursitu, and Chorie), Chorie and (Dursitu, Chorie, Cranscope, Argene and SAB 632) showed highly significant at (p≤ 0.001) to Fusarium oxysporum f.sp. phaseoli, Sclerotium rolfsii, and Rhizoctonia solani while they didn’t exhibit any significant (p < 0.05) difference to Macrophomina phaseolina. In conclusion, those varieties showing resistance characters were recommended for growers.
... Globally, small-grain cereals can be totally deteriorated by pathogenic deuteromycetes Fusarium fungi causing Fusarium head blight (FHB) and ascomycetous Cochliobolus sativus species responsible for spot blotch (SB) and common root rot (CRR), account for ultimate of the major devastating diseases of cereal cultivation (Nutter et al., 1985;Parry et al., 1995;Mathre et al., 2003). FHB results from the development of a complex of at minimal 17 causative agents undergo under Fusarium genus, principally by F. graminearum and F. culmorum. ...
Soluble silicon (Si) helps field crops, whether directly or indirectly, counteract fungal diseases, but in vitro inhibition of Fusarium head blight (FHB) pathogens and Cochliobolus sativus causing spot blotch (SB) and common root rot (CRR) has not been reported. The influence of Si on the mycelial growth of 16 FHB isolates of four agents ( F. culmorum , F. verticillioides , F. solani and F. equiseti ) and 54 C. sativus cultures (32 SB isolates + 22 CRR isolates) was investigated in four experiments. The growth of 70 isolates was not significantly inhibited (P>0.05) on Si added potato dextrose agar (PDA) dishes in the first experiment. However, when the pH of Si added PDA dishes was raised to 8.79, 9.57, 10.19 and 10.59, there were differences (P<0.05) in fungal growth of 16 FHB and 54 C. sativus isolates compared to Si added PDA dishes (pH was equivalent to 6.56) in the second experiment. NaOH added PDA medium was tested for 6 fungal isolates of the five analyzed species in the third experiment and it was found to have similar results to NaOH added Si-PDA. More importantly, differences in growth rates were observed for the 6 isolates in the fourth experiment when discs were transferred from NaOH added Si-PDA to PDA without NaOH and soluble silicon, indicating that NaOH added Si-PDA was fungicidal rather than fungistatic. Our results provide conclusive evidence that inhibition of fungal growth was principally due to the alkaline pH effect of NaOH added to Si PDA dishes. No fungicidal effects of Si were observed, suggesting that reduction of FHB, SB and CRR diseases can not be achieved through direct silicon application. Thus, our data highlight that other physical, biochemical, and/or molecular defense mechanisms could be behind the possible decreases in severity of FHB, SB and CRR diseases in cereal plants treated with low concentrations of Si. As far as we know, this is the first work exploring the fungicidal effect of Si on mycelial growth of causative agents of FHB, SB and CRR diseases in vitro .
... These results are consistent with many studies such as (Hassan, 2012), the inhibitory capacity of P. fluorescens to their ability to produce multiple types of antibiotics including Oligomycine, Oomycine, Phenazine-1-carboxylic acid (PCA), Pyoluterin (Plt) and Pymolnitrin (Pln) that the most important antibiotics produced by P. fluorescens in contrast with Fusarium graminearum and Fusarium moniliforme (Pal et al., 2001). Also, a study conducted by (Mathre et al., 2003), it was reported that P. fluorescens was capable of producing 2,4-Diacetylphloroglucinol 2,4-DPG), which inhibits the growth of many fungi-causing diseases. ...
The improper packaging and storage of oranges (Citrus sinensis) may result in decay it and growth of microorganisms, including Aspergillus spp. these fungi are omnipresent and growing on post-harvest fruits. Certain species of Aspergillus produce toxins that can affect humans and animals health. This study aimed to isolate Aspergillus niger from moldy oranges, test its ability to produce aflatoxin using the Saito and Machida method, and evaluation of their toxicity of some biochemical parameters in white rat males. Moreover, the inhibition efficiency of silver nanoparticles (AgNPs), Pseudomonas fluorescens, and Bacillus circulans were assessed against A. niger isolates. The outcome of screening all nine isolates by the Saito and Machida method has shown the capability of one isolate to produce aflatoxins in large amounts. The filtrate of this isolate showed an increase in the level of GPT and GOT enzymes (24.2 U/ml and 18.3 U/ml) respectively, compared to the non-producing aflatoxins isolate and the control (16.6 and 12.2 U/ml) and (8.5 and 8.2 U/ml) respectively. Glucose level was increased to (130.2 mg/dl) in the rats treated with the filtrate of aflatoxins producer isolate compared to (95 mg/dl) and (86.4 mg/dl) treated with the filtrate of the non-producer isolate and the control respectively. Additionally, the LDL-cholesterol level was reduced to 120.2 mg/dl, and 101 mg/dl with the filtrate producer and the non-producer aflatoxins isolates respectively compared to 144.3 mg/dl for the control. AgNPs have shown an inhibitory effect against A. niger growth with the largest inhibition zone of 28.38 mm at a concentration of 100µl was recorded. On the other hand, Pseudomonas fluorescens and Bacillus circulans have also shown an excellent inhibition rate (100%) at the concentration of 2 g/L of the fungus filtrate. These results exposed that AgNPs are able to inhibit A. niger, and consequently, AgNPs can be used as an antifungal candidate.
... Bipolaris sorokiniana is distributed worldwide in all of the major cereal growing regions. Within a region, it is rare to find a field that does not harbor the pathogen at some level of inoculum (Mathre et al., 2003). Two species of Bipolaris were identified as B. sorokiniana and B. australiensis. ...
In the growing season of 2016-17, the fungal agents associated with crown and root rot of wheat in the Kerman province of Iran were identified. For this purpose, different fields were randomly selected for sampling and percentages of disease were estimated. Infected parts of root and crown were surface sterilized and cultured on Potato Dextrose Agar medium. A total of 260 isolates were obtained and identified on the basis of macroscopic and microscopic characters and valid keys. Of the total isolates, 212 belonged to Fusarium, 28 to Bipolaris and 20 isolates belonged to Drechslera species. Fungal species included F. oxysporum (96 isolates), F. nivale (20 isolates), F. poae (18 isolates), F. anthophilum (9 isolates), F. subglutinans (22 isolates), F. solani (32 isolates), F. culmorum (11 isolate), F. proliferatum (2 isolate), F. chlamydosporum (2 isolates), B. kusanoi (11 isolates), B. australiensis (17 isolates) and D. tetrarrhene (20 isolates). The pathogenicity test was conducted using greenhouse root dip technique. The pathogenicity confirmed five Fusarium species, two Bipolaris and one Drechslera species associated with wheat root and crown rot in Kerman province of Iran. It is concluded that wheat root and crown rot is fairly distributed in the Kerman province and showed virulence of varying degrees demanding strict control measures to minimize losses.
... CRR is considered economically important because it can cause marked reduction in yield and quality of the crop (Van Leur et al., 1997;Kumar et al., 2002). This disease produces a brown to black discoloration of the subcrown internode (SCI), therefore, the presence and severity can be determined by pulling up plants and examining SCI for disease (1 2 T Stack 1 2 T and 1 2 T McMullen 1 2 T 1 3 T 19991 3 T ; Mathre et al., 2003). ...
Cochliobolus sativus, the causal agent of common root rot (CRR), is a devastating fungal pathogen of barley that can cause significant yield losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, CRR-resistant barley germplasm was developed by crossing three resistant-by-susceptible cultivars currently used in Europe and West Asia. Following greenhouse evaluations of 150 doubled haploid lines derived from these crosses, 40 lines were evaluated under artificial infection conditions using incidence and severity parameters during two consecutive seasons. Data showed significant differences among barley lines with a continuum of resistance levels ranging from highly susceptible to resistant which were consistent in both seasons. However, five promising lines had slightly lower CRR disease than the others. Additionally, significant differences (P <0.05) in mean incidence and severity values were found among lines, with values being consistently higher in the susceptible ones. However, CRR severity increased linearly as incidence increased in both seasons. All together, the present study suggests that, the newly identified resistance lines can serve as potential donors for ongoing CRR resistance breeding program to generate high-yielding commercial barley cultivars, and that the positive correlation between CRR parameters I and S may be beneficial for many types of studies on this disease.
... Shoem.], is an economically important disease of barley, wheat and other small grains in semi-arid climates worldwide (Mc-Kayet al., 2018). CRR causes a brown to black discoloration of the subcrown internodes (SCIs) of wheat (Triticum aestivum L.), which is directly related to yield losses (Mathre et al., 2003;Fernandez Holzgang, 2009). ...
The yield response of widely grown cultivars and landraces of Syrian wheat challenged with common root rot (CRR: Cochliobolus sativus ) was measured by comparing plots with and without artificial inoculation under experimental conditions in two consecutive seasons. The results showed that response to CRR differed depending on the susceptibility levels of the wheat cultivars, and that the disease significantly ( P <0.05) reduced grain yield, number of tillers and kernel weight. The diseased plants had fewer tillers which consequently reduced grain yield per plant. Yield losses of Triticum durum cultivars were higher than those of Triticum aestivum . In addition, the T. durum landrace Horani exhibited the best level of resistance to the disease, which indicates that this landrace might be a candidate donor for resistance in future breeding programmes. As CRR can dramatically reduce wheat grain yields under favorable conditions, management practices that reduce disease severity are highly recommended.
... Обикновено кореновата система на растенията е засегната в една или друга степен през всички фази от вегетационния период. Причиняваните заболявания се характеризират с прояви на не-кроза по корените и основата на стъблата на болните растения (Saari, 1985;Weise, 1987;Mathre et al., 2003;Cook, 2012). ...
... По основата на стъблата и корените на всички симптоматични растения беше наблюдавано гниене и покафеняване на тъканите. Наблюдаваната симптоматика по посевите в нашата страна не се отличава от описаните в литературата прояви на кореново и базично гниене по житни култури със слята повърхност (Karadjova, 1979;Dimitrov, 1980;Mathre, 1997;Weise, 1987;Mathre et al., 2003;Cook, 2012). В пет от обследваните посеви (3.3% от общия брой обследвани), в райони около Божурище, Карнобат, Добрич, Шумен и Тутракан, не бяха отчетени видими прояви на заболяване. ...
Small grain cereal crops including wheat, barley, rye, oats, triticale, einkorn etc. are subject to attacks of various soil inhabiting plant pathogenic fungi and fungus-like organisms. All growth stages of cereal crops are susceptible to infections. Attacks lead to pre-emergence decay of seeds, post-emergence dаmping-off of cereal seedlings, root and lower stem rot in later growth stages of the infected cereals. In individual cases, infection proceeds without obvious symptoms until favourable conditions arise or disease remains latent to the end of growing season and harvesting. Results of the present study show that fungi of genus Fusarium are the most frequent soilborne pathogens isolated from cereal crops in the country. Predominating species include F. oxysporum, F. graminearum and F. culmorum, constituting respectively 32%, 22% and 12% of the total number of pathogenic isolates obtained from the roots and lower stems of cereal plants. Other Fusarium species, such as F. Sporotrichiella and F. equiseti, occur sporadically in a few fields grown with cereals. Other soil inhabiting pathogens, associated with root rot and stem base necrotic lesions on cereal crops are Drechslera sorokiniana and Rhizoctonia solani, constituting respectively 11% and 8% of the total number of isolated fungi. Fungus-like isolates of genus Pythium, P. ultimum in particular, and some currently unidentified Pythium spp., represent 10% of isolated fungi. The representatives of this genus are among the most prevalent pathogens, attacking root system of cereal plants, cultivated in waterlogged and cool soils. These species can infect cereal plants either individually or in combinations of two and more pathogens. Mixed infections with Fusarium spp., Pythium spp. and Rhizoctonia solani occur in some of the surveyed cereal fields in the country. Economic losses caused by soilborne diseases of cereal crops in various grain-producing areas vary over the years and depend on the host species, soil, climatic, and agronomical conditions of growing.
... Des études antérieures ont montré que les agents des pourritures racinaires affectaient la germination, la levée et aussi induisaient la mort des plantules (Verma et Spurr, 1987 ;Lyamani, 1988 ;Khabouze, 1988 ;Mergoum, 1991 ;Wagacha et Muthomi, 2007). Pour s'assurer de la nature exacte de la maladie, quelques plantes atteintes doivent être arrachées afin d'observer leur système racinaire dont des taches brunes sont observées sur le collet, le sous-collet et les racines séminales (Mathre et al., 2003). ...
... Dans les cas extrêmes, les plantules peuvent mourir. Cependant, dans la plupart des cas, elles arrivent à survivre en ayant un retard de croissance(Mathre et al., 2003). ...
Abstract
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n Morocco, cereals root rots disease, incited by Fusarium culmorum, causes yield losses of 12-17%, hence the importance of seeking a suitable method and environmentally friendly to control of this disease is of great help to cereal production. In this regard, this study herein aimed to control this disease management of soil fertilization including nitrogen, phosphorus and potassium. The experiment was laid out as strip bloc of four repetitions within which, inoculation treatments of two level (inoculated and non-inoculated) and fertilizers’ treatments of six levels (DAP, DAP+K, DAP + 33% N, DAP + 46% N, DAP + 33% +K, DAP+46+K, were crossed together. Inoculum was added as inoculated seeds of durum wheat and the experiment was undertaken under irrigated and non-irrigated conditions. The whole experiment was repeated within two consecutive agricultural seasons (2014-2015 and 2015-2016). Results showed that root rot is much more favored by severe drought and can cause total crop failure, and no fertilization management can overcome root rot negative impact. However and under wheat crown rot stress, use of nitrogen as DAP + urea in the presence of milled water stress can significantly increase disease severity. However, the use ammonium nitrate (33% N) instead was found to significantly reduce disease severity. Durum grain quality was highly dependent on nitrogen application, especially when potassium was added before sowing. Thus and under biotic stress due to Fusarium culmorum, improving grain production in arid and semi-arid areas should be achieved by the use of ammonium nitrate as cereal top dressing.
... The management of disease is usually achieved by using chemicals. Plant extracts and plant based formulations appear promising in the control of phytopathogenic fungi including B. sorokiniana (Mathre et al., 2003;Salehpour et al., 2005;Akhter et al., 2006;Acharya et al., 2011;Hasan et al., 2012;Perelló et al., 2013a;Hossain et al., 2015;Bahadar et al., 2016). In the present study, we determined inhibitory effect of extracts from 37 plants collected from different places of Karnataka, India. ...
... lm) with 3–11 distoseptate somewhat larger than Curvularia species. Bipolaris sorokiniana is a destructive plant pathogen commonly infecting cereal plants such as barley, wheat and rye, causing crown rot, root rot, seedling blight and spot blotch disease (Zhong and Steffenson 2001; Mathre et al. 2003; Meldrum et al. 2004).4 Morphological characteristics of C. geniculata. ...
Curvularia species are important phytopathogens reported worldwide. They are closely related; consist of major destructive pathogens mainly for grasses and cereal plants including rice (Oryza sativa). A leaf spot symptom of rice is one of the common symptoms found in the rice field and caused reduction of rice yield. However, there are no reports on Curvularia species associated with rice leaves showing spot symptoms. The objectives are to isolate and characterize Curvularia and related species from leaf spot of rice by using morphological and molecular characterization and to determine the phylogenetic relationship between the isolated fungi. Fungal isolation was done from diseased rice leaves showing leaf spot symptoms collected throughout Peninsular Malaysia. Thirty-three isolates were recovered and identified based on their morphological characteristics such as conidia morphology, colony appearance, pigmentation and growth rate for species delimitation. Internal transcribed spacer (ITS) region was amplified to confirm the species identification. The 33 isolates were identified as Bipolaris sorokiniana (10 isolates), Curvularia hawaiiensis (8 isolates), C. geniculata (6 isolates), C. eragrostidis (6 isolates), C. aeria (2 isolates) and C. lunata (1 isolate). A phylogenetic tree was constructed based on ITS sequences using neighbour-joining method. The tree grouped members of Curvularia and Bipolaris into different clades. The phylogenetic tree indicated that the presence of two groups of fungi species; highly virulent and mild pathogens. In conclusion, Curvularia species and Bipolaris sorokiniana were present in rice field in Malaysia and associated with leaf spot of rice.
