Sclerotium Rolfsii Sacc Research Articles

In vitro exploration of phytoextracts against stem rot of white onion (Allium cepa L.) caused by Sclerotium rolfsii Sacc.

In vitro exploration of phytoextracts against stem rot of white onion (Allium cepa L.) caused by Sclerotium rolfsii Sacc.

Biological Suppression of Sclerotium rolfsii in Groundnut Cultivation: A Path Towards Sustainable Disease Management

Stem rot of groundnut caused by Sclerotium rolfsii Sacc, is a major soil borne disease which impact on groundnut cultivation both in India and globally. The primary objective of this study was to assess the antagonistic potential of biocontrol agents against the pathogen, both individually and in combination, under In vitro and glasshouse conditions. The results of the present investigation indicated that the application of microbial consortia was more effective against Sclerotium rolfsii than individual bioagents. Specifically, seed treatment with microbial consortia MC1, MC2, MC3, and MC4 resulted in lower disease incidence with 13.80%, 16.01%, 20.0%, and 22.60% respectively, compared to the pathogen check, which had a 74.12% PDI. Additionally, these treatments also enhanced plant growth through improved plant growth-promoting traits under glasshouse conditions.

Catalyst-free synthesis of novel α-trifluoromethylated tertiary alcohols bearing azaarenes as potential antifungal agents

Herein, α-trifluoromethylated tertiary alcohols bearing azaarenes were successfully synthesized via the reaction of 2-methyl azaarenes and CF3-substituted 1,3-diols with high yields under catalyst-free, mild conditions. The antifungal activities against Gaeumannomyces graminis var tritici, Rhizoctonia cerealis, Fusarium graminearum, Rhizoctonia solani, Fusarium moniliforme, Sclerotium rolfsii Sacc were investigated. The bioassay results indicated that the antifungal activity against Gaeumannomyces graminis var tritici was obviously better compared to other five fungi and compound 3dd displayed the highest activity, with an EC50 value of 27.73 μg/mL in vitro.

In vitro exploration of bioagents and fungicides against stem rot of white onion (Allium cepa L.) caused by Sclerotium rolfsii Sacc.

In vitro exploration of bioagents and fungicides against stem rot of white onion (Allium cepa L.) caused by Sclerotium rolfsii Sacc.

Roving Survey of Collar Rot Disease of Chickpea Caused by Sclerotium rolfsii Sacc. in Rajasthan, India

Roving Survey of Collar Rot Disease of Chickpea Caused by Sclerotium rolfsii Sacc. in Rajasthan, India

Evaluation and Characterization of Rhizobacteria and Endophytes for Antagonistic and Growth Promotional Traits Against Collar Rot (Sclerotium rolfsii Sacc.) of Soybean

Background: Sclerotium rolfsii Sacc. is one of the destructive soil-borne plant pathogens due to its significant loss in terms of yield and quality in several crop plants including soybean. Use of biocontrol agents in the management of disease is an ecofriendly strategy. Therefore, the study aimed to assess in vitro antagonisticactivity of rhizobacteria and endophytes against Sclerotium rolfsii following dual culture technique. Methods: A total of 75 rhizobacterial isolates, 3 endophytes along with reference cultures were evaluated for the antagonistic activity against Sclerotium rolfsii following dual culture technique. The effective rhizobacterial isolates were tested for the various plat growth promoting rhizobacteria traits viz., indole acetic acid production, siderophore production, Phosphate solubilization, production of ammonia, hydrogen cyanide production and chitinase test following the standard procedure. Result: The two promising rhizobacterial strains i.e., AUUB 209 (Streptomyces enissocaesilis) and Streptomyces racemochromogenes (AUDT 626) were found effective with 76.79 and 64.75 percent mycelial inhibition of Sclerotium rolfsii under in vitro. The antagonistic activity of these two rhizobacteria is mainly attributed to the positive confirmation of various PGPR activities viz., production of Indole acetic acid, siderophore, phosphate solubilization and chitinase production.

Evaluation of Homoeopathic Drugs against Sclerotium rolfsii Sacc. in Groundnut (Arachis hypogea L.)

Evaluation of Homoeopathic Drugs against Sclerotium rolfsii Sacc. in Groundnut (Arachis hypogea L.)

Efficacy of Different Bioagents against Collar Rot Disease of Chickpea Incited by Sclerotium rolfsii under In vitro Conditions

Sclerotium rolfsii is a destructive soil-borne pathogen causes over 500 spp. in 100 families of agricultural and horticultural crops. Collar rot disease of chickpea caused by pathogen Sclerotium rolfsii Sacc. First symptom associated with S. rolfsii are usually girdling or rotting at basal or collar region of the stem resulting yellowing and wilting of entire plant. In the current study, the seven microorganisms were evaluated by dual culture technique for their antagonistic effect against S. rolfsii under In-vitro conditions. Maximum mycelial growth inhibition (80.97%) was noticed in Trichoderma harzianum which was followed by Pseudomonas fluorescens (74.04%). Least inhibition was observed in T. virens (45.53%). The results showed that the application of these bioagents were successfully decreases the disease incidence in chickpea.

Incidence of Stem Rot of Cluster-bean (Cyamopsis tetragonoloba) in Major Growing Areas of Rajasthan, India

A survey was conducted in major cluster bean growing districts of Rajasthan during Kharif season 2022 and 2023 which showed the stem rot disease caused by Sclerotium rolfsii Sacc. is an imperative pathological problem, mostly in Bikaner, Shri Ganganagar and Hanumangarh districts. Average disease incidence was 22.33 per cent recorded in surveyed districts of Rajasthan. Highest average disease incidence (27.67%) was reported in Shri Ganganagar followed by Hanumangarh (22.50%) while lowest in Bikaner (16.83%) district.

Cultural and Morphological Characterization of Streptomyces and Interaction Study with Sclerotium rolfsii by SEM

Stem rot caused by Sclerotium rolfsii Sacc. is a major constraint in the production and productivity of the groundnut. Management of stem rot disease is very difficult due to soil borne nature, wide host range of S. rolfsii and lack of disease resistance in existing commercial cultivars. Biological control with potential Streptomyces is receiving greater attention all over the world. Studies were conducted on collection and isolation of Streptomyces, their mechanism of action, cultural and morphological characteristics, its efficacy against S. rolfsii with Scanning electron microscope(SEM). Roving survey was conducted in major groundnut growing regions of Andhra Pradesh. During survey 180 soil samples were collected from groundnut rhizosphere and 50 Streptomyces isolates were isolated from different soil samples. Twenty Streptomyces isolates were tested for their growth rate and antifungal activity against groundnut stem rot pathogen, S.rolfsii under in vitro conditions using dual culture method. Among twenty isolates of Streptomyces, five isolates showed maximum inhibition of S. rolfsii. These five isolates were characterized based on cultural and morphological characters. The study involved in differentiating various characters viz., type of spore chain, colony margins, shape of spore chains, colour of spore mass and spore surface. The morphology of the spore chains varied across the isolates showing the filamentous (Ggd), spiral (Kyd and Lrp) and Rectus flexibilis (Kdr and Mkc). SEM studies revealed that inhibition of the growth of S. rolfsii by Streptomyces was mainly due to exhibition of irregular distortions at contact site of the pathogen and collapse of the fungal hyphae and this might be due to the production of secondary metabolites and extracellular enzymes.

Diversity Studies of Sclerotium rolfsii Sacc. Isolates Associated with Collar Rot of Soybean Through Molecular and Biochemical Approaches

Background: Sclerotium rolfsii Sacc. is one of the potential soil-borne plant pathogens due to its significant loss in terms of yield and quality in several crop plants. In soybean the pathogen is associated with collar rot disease. Methods: Sixteen samples which were showing collar rot symptoms were collected from different soybean growing regions of the country and were subjected for isolation and purification. Molecular detection was carried out using ITS1/4 primers followed by phylogenetic analysis was performed using the MEGA 11 bioinformatics tool. Further, the biochemical test was made for oxalic acid production to determine the variability across the isolate. Result: DNA was amplified for ITS rDNA region at 650-700 bp in all the sixteen isolates. BLAST detection of nucleotide sequence of sixteen isolates framed mainly into two distinct phylogenetic clusters. Cluster B consisted of two isolates (MPSe 1 and MHSa 3) whereas, Cluster A contains the remaining fourteen isolates. There was a variation with respect to oxalic acid production among the isolates which was in the rage of 1.15 to 2.23 mg/ml.

Microbial Interactions in the Management of Groundnut Stem Rot

Groundnut (Arachis hypogaea L.) is an important oil seed crop in the world belonging to the Leguminosae family. It is one of the essential food and cash crops of our country. In India, a large number of diseases attack groundnut [1]. Among soil borne diseases, stem rot or white mold caused by Sclerotium rolfsii Sacc. [2] is an important disease causing significant yield losses in several groundnut growing countries (Mehan et al., 1994). Sclerotium rolfsii Sacc. is a destructive soil borne fungal pathogen of oil seed crop in India. Different practices are recommended for management of groundnut stem rot such as deep summer ploughing, destruction of plant debris, crop rotation with jowar and bajra, seed treatment with carbendazim or captan or mancozeb or tebuconazole, soil drenching with hexaconazole, application of ammonium sulphate or calcium ammonium nitrate instead of urea and application of gypsum at flowering stage. Further, no single treatment is full proof and disease continues to cause losses in farmers’ fields. Biological control offers an interesting alternative to fungicides for sustainable management of soil borne diseases. Biocontrol is a non-chemical measure, could be effective as chemical control by various techniques. Among the techniques, the mixture of antagonists was studied to enchance the control efficacy. In most studies, the involvement of only mechanism of biological control is demonstrated. Involvement of more than one mechanism has been reported in only a few systems. Use of several biocontrol agents with several mechanisms of control fits in well with the concepts of integrated disease management, in which several means of disease suppression are applied concurrently. When single or more means of mechanisms are not effective, the others may compensate for the former absence. The present study, involved three major bacterial antagonists viz., Streptomyces violaceusniger, Streptomyces exfoliatus and Pseudomonas fluorescens to find out the effective dose of mixtures. The different doses from 10-1 to 10-5 were studied, the dose 10-1 of Streptomyces violaceusniger have more efficiency of 86.70, than S. exfoliatus. The efficacy of Streptomyces violaceusniger with combination of other antagonists were tested and found that, the mixture of Streptomyces violaceusniger and P. fluorescens have synergistic activity than any other combinations which have synergistic factor greater than one.

Sustainable management of Stem rot of groundnut caused by Sclerotium rolfsii Sacc. by bioinoculants fortified with humic acid

Groundnut (Arachis hypogaea L.) is considered as an important edible leguminous oilseed crop belongs to family Fabaceae. The cultivation of groundnut is hindered by several biotic and abiotic stresses. Stem rot disease incited by Sclerotium rolfsii Sacc. is one of the most destructive diseases of peanut and it deteriorates the quality and quantity of peanut. Management of the stem rot was found to be difficult, uneconomical and harmful for the environment. Keeping in view of the residual nature of fungicides on the environment, the idea of bioinoculants was undertaken. Biological control offers a sustainable management of soil borne diseases.The present study was undertaken to find out the efficacy of bioinoculants such as Streptomyces, Rhizobium and Bacillus alone and in combined effect of bioinoculants fortified with Humic acid against stem rot incidences. The groundnut plants were treated in combined application of Streptomyces albofaciens, B. japonicum and Bacillus subtilis fortified with humic acid as seed treatment @ 10g/kg of seeds plus soil application @ 2.5 kg ha-1(T6) recorded minimum diseases incidence and significantly enhanced the yield parameters.

Management of Tropical Sugarbeet Root Rot (Sclerotium rolfsii Sacc.) by Fungicide and Rhizosphere Biocontrol Agents

Management of Tropical Sugarbeet Root Rot (Sclerotium rolfsii Sacc.) by Fungicide and Rhizosphere Biocontrol Agents

Status of Stem Rot Incidence of Groundnut Caused by Sclerotium rolfsii inNorthern Eastern Karnataka

Groundnut is regarded as “King of oilseed crops” on account of its diversified uses. It’s productivity is challenged by several biotic and abiotic stresses. Sclerotium rolfsii Sacc. is one of the major constraints to groundnut production which causes a yield loss of about 25 – 80 %. Hence, the roving survey was conducted during Kharif 2021 in North-Eastern Karnataka region. The mean stem rot incidence among the different districts surveyed ranged between 18.89-36.28 per cent. The maximum stem rot incidence was recorded in Vijayanagar (36.28 %) followed by Ballari district (32.83 %). Whereas, minimum stem rot was recorded in Koppal district (18.89 %).

Unravelling the potential of effective seed bacterial endophyte in groundnut forstem rot disease (Sclerotium rolfsii) management

Groundnut (Arachis hypogaea L.) is known as “King of oilseeds” which is grown extensively in both Kharif and Rabi/Summer seasons.Several among the several pathogens, Stem rot caused by Sclerotium rolfsii Sacc. causes the yield loss up to 80 per cent during favourable conditions. Hence, an attempt has been made to isolate bacterial endophytes for biocontrol management from peanut seeds as an alternative approach. Sixteen isolates (EGN1- EGN16) isolated from peanut were tested against Sclerotium rolfsii under in vitro. Further, the effective isolates were further analyzed for the presence of thermo stable compounds, profiling of secondary metabolites through GC-MS analysis, growth promotion test (rhizo scanner) and pot culture experiment. The results showed that talc formulation of effective isolate EGN 1 (Pseudomonas sp.) significantly increased the vigour index (4902.81), germination rate (91.3per cent), root length (28.1 cm) and shoot length (25.6 cm) along with the simultaneous reduction in disease incidence of 5.54 %.

Evaluation of fungicides against stem rot of groundnut caused by Sclerotium rolfsii Sacc under in vitro condition

The efficacy of five test fungicides viz., carboxin 37.5 % + thiram 37.5 %, tebuconazole 25 % EC, mancozeb 75 %WP, penflufen 13.28 % w/w + trifloxystrobin 13.28 % w/w FS and chlorothalonil 75 % WP were tested under in vitro by poisoned food technique against S. rolfsii in groundnut. Among five fungicides, penflufen + trifloxystrobin fungicide were found highly effective at all the concentrations (250, 500, 750 and 1000 ppm) tested and inhibited 100.0 % mycelial growth of S. rolfsii in groundnut as compared to control.

Evaluation of soybean genotypes against collar rot disease caused by Sclerotium rolfsii Sacc.

Collar rot caused by S. rolfsii is one of the economical diseases of soybean that can cause up to 30-40% yield loss in India. A total of 18 soybean genotypes were screened artificially during 2021 at ICAR-IISR, Indore, to study the virulence among the fungal isolates as well as to identify the resistance sources. Based on pathogenicity, Indore isolate (SRI) was found to be more virulent than Assam isolate (SRA). On the basis of percent emergence (PE) and the disease indices - root weight of inoculation (RWI) and ratio of root weight (RRW), genotypes JS 335, JS 20-34 and MACS 1620 were resistant against SRI whereas RSC 10-52 and JS 335 were found to be potential donors for resistance against SRA.

Phenotypic evaluation of USDA peanut (Arachis hypogaea L.) mini-core collection for resistance against stem rot caused by Sclerotium rolfsii Sacc.

Sclerotium rolfsii is a necrotrophic fungus that causes devastating stem rot disease on peanuts under high temperature and humidity conditions. Developing more resistant stem rot varieties is a better disease management strategy from an economic and environmental point of view. In this study, 105 peanut accessions from the USDA mini-core collection were screened for resistance against stem rot under growth chamber and greenhouse conditions at the New Mexico State University Agricultural Science Center in Clovis, NM, USA. The accessions were inoculated with a virulent isolate of S. rolfsii, and disease development was monitored and scored at 5, 7, 9, 11, and 17-days post-inoculation (DPI). Mean disease score, lesion length and broad sense heritability were calculated, and cluster analysis was performed. Though the accessions were not significantly different for the mean disease parameters, numerical differences were observed in disease score and lesion length among the accessions at 17-DPI. Eleven accessions showed moderate resistance and performed better than stem rot resistant commercial cultivar, ‘G03L’, and ninety-four accessions were susceptible based on mean disease scores under both growing conditions. Low broad-sense heritability for disease score (0.05 to 0.06) and lesion length (0.03 to 0.06) under different environments indicates that most of the variance for these traits is due to environmental effects, and that stem rot resistance can be a complex trait. The identified resistant accessions can be used for genotyping and finding major QTLs through genome-wide association mapping to dissect genetic basis of stem rot resistance in peanuts. This information would be helpful to the peanut breeding program to develop more resistant varieties.

Compost Applications Improve Soil Fertility, Sugar Beet Performances, and Decrease Sclerotium rolfsii Sacc. Survival Under Saline Irrigation in a Semi-Arid Climate

Compost Applications Improve Soil Fertility, Sugar Beet Performances, and Decrease Sclerotium rolfsii Sacc. Survival Under Saline Irrigation in a Semi-Arid Climate