Browsing by Author "Asha Sinha"

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Ancient, mid-time, and recent history of seed pathology
(Springer Singapore, 2020) Seweta Srivastava; Ravindra Kumar; Sumant Bindal; Vinit Pratap Singh; Meenakshi Rana; Jay Prakash Singh; Asha Sinha
Seed is the basic unit of crop production. An optimum plant count depends on seed for their next progeny. Issues related to seed should be handled very carefully, since sowing of a poor-quality seed leads to undesirable loss in plant stand and hence crop yield. Focus on seed quality and seed health has been a point of serious consideration since time immemorial. Seed-related aspects are puzzling the researchers since long back. Well-developed science of seed pathology has been in existence for more than 100 years. Seed pathology includes studies on the mechanism of seed transmission, pathogenesis, epidemiology of seed-borne diseases, and control measures adopted against these diseases, ranging from crop management through chemical control to legislative precautions, as well as the technology of microbiological seed testing by covering the total range of seed-borne pathogens, viz., fungi, bacteria, viruses, nematodes, and physiological defects which may affect any member of the plant kingdom. The various aspects, viz., seed health, management of seed-borne diseases, seed treatments, and their detection and diagnosis techniques, were developed with the time. The systematic application of these techniques leads to the significant availability of healthy and disease-free quality seed. The institutional and technological developments in the science of seed pathology are being discussed in the present chapter. © Springer Nature Singapore Pte Ltd. 2020.
Antagonistic Behavior of Different Bioagents Against Dominant Seed Borne Fungi of Mungbean Seeds Under In Vitro Condition
(Springer India, 2017) Saurabh Singh; Asha Sinha; S.M. Yadav; Bhupendra Kumar Singh; Harendra Singh; Shewta Srivastava; Ravindra Kumar
Pulses are high value crops and generally greater attention is paid to protect them against diseases caused by microbial pathogens after harvest during storage. Use of fungicides may cause environmental hazards besides residual problems. Therefore Trichoderma viride, Trichoderma harzianum, Trichoderma virens, Pseudomonas fluorescence and Bacillus subtilis were evaluated in vitro against seed borne diseases of mungbean seeds. In vitro studies were carried out in both dual culture technique and Agar plate methods. The four dominant fungi of mungbean seeds viz, Aspergillus niger, Penicillium rubrum, Alternaria alternata and Fusarium moniliforme were used to assess their vulnerability to an array of bio-agents. Results showed that all bioagents significantly reduced the percent growth inhibition of all tested fungi. Among all the bioagents T. harzianum was found superior in controlling the seed borne mycoflora of mungbean seeds. Among the fungal pathogens, P. rubrum and A. niger were effectively suppressed by T. harzianum and P. fluorescence. Bacillus subtilis, T. virens and T. viride gave the promising results against all the tested fungi. Trichoderma harzianum showed highest inhibition of mycelium growth of the A. alternata followed by T.viride (8.00 %). Bacterial antagonist, B. subtilis showed intermediate effect against all tested fungi. Trichoderma virens and T. viride showed least effect against all tested seed borne fungi. © 2015, The National Academy of Sciences, India.
Biochemical Changes in Mungbean plants infected by Mungbean yellow mosaic virus
(2010) Asha Sinha; M. Srivastava
In present study effect of Mungbean yellow mosaic virus on the chlorophyll, total nitrogen, protein, total phosphorous and carbohydrate content in three varieties of mungbean plants HUM -2 (Malviya Jagriti), ML-192, Pusa Baisakhi were studied. Total chlorophyll, chlorophyll a, chlorophyll b content and carbohydrate content were lower in virus infected mungbean plant varieties. Total nitrogen, protein increased and total phosphorous content was found to be high in virus infected mungbean leaves. Estimation of chlorophyll in healthy and diseased leaves of mungbean plants at 15, 30, 45, 60 and 75 days were done and absorbance were recorded by spectrophotometer at 663 and 645 nm. Total nitrogen of leaves was measured by modified microkjekldahl method and total protein content was determined by multiplying the total nitrogen content with 6.25. Total phosphorous were estimated by digestion with Tri-acid mixture and reading was taken in spectrophotometer at 470 nm. Determination of carbohydrates were done by total water soluble sugars and starch content. © 2010 Academic Journals Inc.
Bioremediation Potential of Rhizobacteria associated with Plants Under Abiotic Metal Stress
(wiley, 2021) Shrvan Kumar; Saroj Belbase; Asha Sinha; Mukesh Kumar Singh; Brajesh Kumar Mishra; Ravindra Kumar
Biological remediation is considered as the most effective method of toxic metal removal as these are natural, environmentally friendly, low-cost, and high societal acceptance technologies. One such technology is the use of plant growth promoting microbes for bioremediation of heavy metal polluted soil and is quite important in the context of the global climate change and excessive fertilizer use in agricultural soils. This is feasible because microorganisms have developed many resistance mechanisms for survival in the presence of toxic heavy metals in their environment. Microbes also enhance bioavailability of metals from soil by chelation, acidification, and precipitation as, for example, organic acids released by microbes and plant roots lower the soil pH and help in the sequestration of metal ions. Plant growth promoting rhizobacteria (PGPR) are the microorganism basically present in the rhizosphere, which includes the bacterial species Alcaligenes, Azospirillum, Arthrobacter, Acinetobacter, Azoarcus, Bradyrhizobium, Bacillus, Burkholderia, Enterobacter, Erwinia, Flavobacterium, Pseudomonas, Pantoea, Paenibacillus, Rhizobium Azorhizobium, Bradyrhizobium, Allorhizobium, Sinorhizobium, Methylobacterium, Frankia, and Mesorhizobium. Genetically transformed bacteria possess one or more genes to increase the remediation of heavy metals. Against this background, genes for metal chelators, metal homeostasis, transporters, biodegradative enzymes, metal uptake regulators, and biotic and abiotic stress tolerance are important candidates for making recombinant bacteria. The heavy metals Hg, Cr, As, Zn, Cd, Pb, Ur, Se, Ag, Au, and Ni are hazardous heavy metals. Among heavy metals, four heavy metals As, Pb, Cd, Zn, and Hg are considered as the most toxic metals by the US Agency for Toxic Substances and Disease Registry, based on their toxicity, frequency of occurrence, and most importantly, their exposure potential to flora and fauna. The effectiveness of bioremediation depends on several factors such as the nature of the organisms utilized, the prevailing environmental factors at the contaminated site, as well as the degree of the pollutants in that environment. © 2021 John Wiley & Sons Ltd. All rights reserved.
Biotechnological role of fungal microbes in sustainable agriculture
(Plant Archives, 2019) Seweta Srivastava; Sumant Bindal; Meenakshi Rana; Ravindra Kumar; Sangeeta Yadav; Jay Prakash Singh; Asha Sinha
Over the past several decades, advances in biotechnology have been used as a tool to increase food production. Specifically, advances in genetic engineering have made possible the manipulation of crops to increase yield, guaranteeing food supplies for the increasing world population. The broad application of microbes in sustainable agriculture is due to the genetic dependency of plants on the beneficial functions provided by symbiotic cohabitants. Therefore, microbial biotechnology and its applications in sustainable development of agriculture and environmental health are getting better attention. Finally, a brief highlight has been given on the biotechnological role of mycobionts to sustain the agriculture sector. © 2019 Plant Archives. All rights reserved.
Brown Spot of Potato Caused by Alternaria alternata: an Emerging Problem of Potato in Eastern India
(Springer Science and Business Media B.V., 2022) Shrishti Lingwal; Asha Sinha; J.P. Rai; Chandra S. Prabhakar; A. Srinivasaraghavan
Several black to brown colored spots especially on leaf lamina were noticed on the potato crop at an experimental field of Banaras Hindu University, Varanasi (India) during 2015. Such symptoms were reported as brown spot of potato caused by Alternaria alternata elsewhere in the world. To understand the extent of such symptoms, a roving survey was carried out during the 2016 cropping season in thirteen districts of Uttar Pradesh and two districts of Bihar and the presence of brown spot symptom across the region with the percent disease index (PDI) ranging from 17.77 to 40.00% was observed. Forty isolates obtained from surveyed locations grouped into four categories viz., non-pathogenic (10), low pathogenic (09), moderately pathogenic (08) and highly pathogenic (13) based on the pathogenicity test. However, morphologies of 30 pathogenic isolates were found to be similar with A. alternata. The identity of those 30 isolates was further confirmed by PCR using A. alternata specific primers. On the other hand, phylogenetic analysis of rDNA sequence of 13 pathogenic isolates from the present study and published sequences of A. alternata and other related fungi retrieved from GenBank, NCBI has confirmed the identity of brown spot of potato from the surveyed location as Alternaria alternata. © 2022, The Author(s), under exclusive licence to European Association for Potato Research.
Ecological biodiversity measurement of seed mycoflora contamination of freshly harvested in maize growing Zone-II
(Journal of Pure and Applied Microbiology, 2017) Shrvan Kumar; Asha Sinha; Shakshi Singh
Maize is considered third most important cereal crops in the world. In our study the seed mycoflora of freshly harvested maize of zone-II were isolated by Agar plate method (APM) and Blotter plate method (BPM). A total of 9 genera i.e. Aspergillus flavus, A. niger, Bipolaris maydis, Curvularia lunata, Fusarium verticilioides, Penicillium notatum, P. expensum, Rhizopus stolonifer, and Rhizoctonia solani were isolated by standard Agar plate method and 10 fungal genera, i.e. Alternaria alternata, Aspergillus flavus, A. niger, Bipolaris maydis, Curvularia lunata, Fusarium verticilioides, Macrophomina phaseolina, Penicillium notatum, Rhizopus stolonifer, and Rhizoctonia solani by blotter plate method. On the basis of density, frequency and abundance, Aspergillus flavus, A. niger and Rhizopus stolonifer were found as dominate and taken for detail study. The seed lot of this zone is three categories i.e. Original (OS), Partial discolour (PDS) and Discolour seed (DS). Maximum important value index (IVI), Simpson index of dominance (D), Shannon-Weaver index of diversity (H) and Evenness (E) of Aspergillus flavus OS (86.657%, 0.0834, 0.359, 0.184), PDS (63.827%, 0.0453, 0.329, 0.150) and DS (83.467%, 0.0774, 0.356, 0.183) were contributed. In Blotter plate method, highest density of A. niger OS (5.850), A. flavus PDS (4.500), DS (5.225) were recorded. Maximum frequency showed by A. flavus (100.000%) in all categories. The abundance of A. flavus OS (0.350), PDS (0.342), DS (0.407) were recorded. Relative density maximum recorded in A. niger OS (26.401%), A. flavus PDS (19.268%) and DS (26.381%). Relative frequency (RF) and relative abundance (RA) highest were found in A. flavus OS (24.691%, 35.009%), PDS (23.256%, 34.221%) and DS (23.810%, 40.661%). Maximum IVI, Simpson index of dominance, Shannon-Weaver index of diversity and evenness contributed A. flavus OS (80.912%, 0.0727, 0.353, 0.170), PDS (76.744%, 0.0654, 0.349, 0.159) and DS (90.852 %, 0.0917, 0.362, 0.174). These species are some of the common on the maize during storage and spoil the grains.
Effect of fungal biotic stress on physic nut (Jatropha Curcas L.)
(Apple Academic Press, 2015) Seweta Srivastava; Asha Sinha
Jatropha curcas L. is a small tree that grows originally in areas near the equator. The oil plant Jatropha curcas L., a multipurpose drought resistant, perennial plant belonging to Euphorbiaceae family is gaining a lot of importance for the production of bio-diesel. Growth in the automotive industry, along with increases in population and gains in worldwide standards of living, has resulted in greater demand for energy sources such as biodiesel fuel. Seeds are regarded as highly effective means for transporting plant pathogens over long distances. Seed deterioration is defined as summation of all physical, physiological, biochemical changes occurring in a seed, which ultimately lead to its death. Jatropha seeds are constantly subjected to deterioration, which implies an irreversible degenerative change in the quality of seeds after it has reached its maximum quality of seeds after it has reached its maximum quality level. The fungi associated with seeds at the harvest stage and under storage bring about several undesirable changes and degradation of seed constituents, thus making the seed unfit for oil extraction, export purpose, consumption or sowing. These storage mycoflora affect the quality of seeds and as well as the diesel extracted by affecting their biochemical and physicochemical properties which is very essential. Biodiesel, an environmental friendly diesel fuel similar to petro-diesel in combustion properties, has received considerable attention in the recent past worldwide. There is therefore, need to explore alternative nonedible oil for use in production of biodiesel. © 2016 by Apple Academic Press, Inc.
Effect of organic amendments on soil mycoflora
(2010) Ravindra Kumar; Seweta Srivastava; Manisha Srivastava; Asha Sinha
In present study, the influences of different organic soil amendments on soil fungi was studied. Soil organisms carry a wide range of processor that are important for soil health and partially in both natural and managed agricultural scales. The total number of organisms, the diversity of species and activity of soil biota will fluctuate as soil environment changes. Three types of soil amendments and fertilizers viz., urea, FYM and vermicompost were used to amend the cultivated agricultural soil. The fungi were isolated from soil by using dilution plate technique and soil plate method. The dynamics of soil fungi were observed qualitatively as well as quantitatively. The maximum number of fungi was recorded when soil amended with FYM (40.6xl04 g-1), urea (38.8xl04 g-1) of dry soil at different concentration 2.0, 1.5 and 2.0%, respectively. In control where soil was not amended with any organic amendment, the number of fungi was 13.0xl04 to 16.8x104 g-1 14.4xl04 to 16.8x104 g-1 13.8xl04 to 16.8xl04 g-1 in urea, FYM and Vermicompost, respectively. A total 25 fungi were observed during the experimental period. Eighteen were observed when soil amended with urea, twenty-two observed when soil amended with FYM and 20 when soil amended with vermicompost. In control soil only fifteen fungi were recorded. The result showed that the number of fungi was increased in amended soil. Qualitatively, the fungi Rhizopus stolomfer, Aspergillus niger, Aspergillus flavus, Trichoderma harzianum, Penicillium citrinum, Alternaria alternata and Curvularia lunata, White Sterile Mycelium and Black Sterile Mycelium were observed. © 2010 Academic Journals Inc.
Effect of seed-borne mycoflora on protein and amino acid content of Jatropha curcas L. Seeds during storage
(2013) Seweta Srivastava; Manisha Srivastava; Ravindra Kumar; Asha Sinha
Jatropha curcas is a non-edible oil crop predominately used to produce bio-diesel. J. curcas seed meal (with 1 -2 % residual oil) has 58 -64 % crude protein (90 % of which is present in the form of true protein) and levels of essential amino acids except lysine are higher which were constantly effected by the seed-borne mycoflora during storage. The objective of this study was to estimate the change in protein and amino acid content of Jatropha seeds after deterioration. For protein and amino acid estimations fresh, stored as well as infested Jatropha seeds were used. Whole seed and kernels were infested with six fungi isolated from Jatropha curcas seeds during storage viz. Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Fusarium chlamydosporum and Penicillium glabrum separately. Four different concentrations of seed samples viz. 50μl, 100μl, 150μl and 200μl were taken for the protein and amino acid estimation of stored as well as infested Jatropha seeds. Protein content of two years stored Jatropha seeds at 200μl concentration is much less as compared to fresh seeds. Minimum protein content was found in Fusarium chlamydosporum infested Jatropha seeds i.e., 10μg/ml which is very less as compared to fresh seeds i.e., 110.67μg/ ml at 50μl concentration respectively. Protein profiling by SDS-PAGE revealed that the maximum number of bands was shown by fresh Jatropha seeds and kernels. The presence or absence of bands in protein profiling might be responsible for presence or absence of protein of that size. Surprisingly, amino acids of infested seeds were increased due fungal infection and maximum amino acids content was found in Aspergillus flavus infested kernels at 200μl concentration followed by Fusarium chlamydosporum and Aspergillus flavus infested Jatropha kernels.
Evaluation of biocontrol potential of some fungal decomposers of Sesbania aculeata L. Green manure against some soil-borne plant pathogens
(Triveni Enterprises, 2017) Ravindra Kumar; Asha Sinha; Seweta Srivastava; Gaurav Mahajan
Aim: Soil borne phytopathogens are one of the major concern of today's agricultural system. In the present study, dominant fungal decomposers were selected and their potential as biological control agents was evaluated against some soil borne plantpathogens. Methodology: Effect of green manure amendment on the sclerotia viability of three soil-borne plant pathogens viz., Sclerotium rolfsii, Rhizoctonia solani and Sclerotinia sclerotiorum, effect of fungal decomposers on soil-borne phytopathogens in dual culture, effect of volatile and non-volatile metabolites of dominant fungal decomposers on the radial growth and sclerotia production of test pathogens were evaluated. Results: Green manure amendment resulted in reduced in sclerotia of S. rolfsii, R. solani and S. sclerotiorum by 40, 36 and 36.50%, respectively. In dual culture, the maximum growth inhibition of S. rolfsii, R. solani and S. sclerotiorum with Trichoderma harzianum were 49.95, 47.62 and 57.83%, respectively The maximum inhibition of S. rolfsii and S. sclerotiorum caused by the volatile metabolites produced by Trichoderma harzianum were 56.64 and 43.95%, whereas the maximum inhibition of R. solani was caused by volatile metabolites of Penicillium citrinum (44.96%). The maximum inhibition of S. rolfsii, R. solani and S. sclerotiorum through non-volatile metabolites of Trichoderma harzianum were 51.04,57.30 and 49.10%, respectively. The maximum reduction in sclerotia of S. rolfsii, R. solani and S. sclerotiorum with Trichoderma harzianum were 86.44, 88.54 and 88.20% respectively, under dual culture after 21 days of incubation. The maximum reduction in sclerotia of S. rolfsii, R. solani and S. sclerotiorum with Trichoderma harzianum were 95.42, 93.60 and 91.32%, respectively, under the effect of volatile metabolites after 21 days of incubation. The maximum reduction in sclerotia of S. rolfsii, R. solani and S. sclerotiorum with Trichoderma harzianum were 87.46, 79.74 and 85.10% respectively, under the effect of non-volatile metabolites after 21 days of incubation. Interpretation: All eight fungal decomposers effectively contribute in controlling the soil borne phytopathogens. Overall T harzianum, Aspergillus niger and Penicillium citrinum proved as potential bio-control agents against all soil borne plant pathogens viz., S. rolfsii, R. solani and S. sclerotiorum. © Triveni Enterprises, Lucknow (India).
Evaluation of different fungicides and antagonists in vitro and in vivo condition against alternaria blight of pigeonpea
(Agricultural Research Communication Centre, 2020) Laxman Prasad Balai; R.B. Singh; Asha Sinha; S.M. Yadav
Efficacy of bio agents and systemic and non-systemic fungicides @ 50, 100, 200, 250 and 500 ppm were evaluated In vitro against Alternaria tenuissima causing Alternaria blight of pigeonpea. The relative efficacy of bio agents were studied in dual culture plate method showed that Hypocrea rufa was found most effective antagonist against test pathogen followed by T. harzianum. Efficacy of six fungicides was tested in poisoned food technique. Among the six fungicides tested, mancozeb was found most effective against test pathogen followed by Chlorothalonil and Iprodione. Propineb was least effective against mycelial growth of test pathogen. Raise in concentration of fungicides was more effective in inhibiting the mycelial growth of the pathogen. Field condition studies were found out to be the effect of seed treatment, foliar spray, seed treatment+ foliar spray with six fungicides and two bio agents and their combination used as against pathogen. Artificial inoculation of mass culture of A. tenuissima was done in the inoculated seed treatment and after foliar spray on the plants sixty DAS. Amongst them twenty five treatments, combination of Mancozeb with H. rufa was found most effective in reducing the disease intensity and disease control followed by Mancozeb with T. harzianum and Mancozeb alone, respectively. While, T. harzianum alone was least effective and maximum disease intensity recorded as a compared to control followed by T. harzianum with double dose and T. harzianum and H. rufa combination treatment, respectively. In case of both seed treatment and foliar spray of Mancozeb with H. rufa was found most effective in reducing the disease intensity and disease control followed by combination of Mancozeb with T. harzianum and Mancozeb alone, respectively. Whereas, least effective and maximum disease intensity and disease control were observed T. harzianum alone as compared to control. © 2020, Agricultural Research Communication Centre. All rights reserved.
Evaluation of seed-borne mycoflora of rice (Oryza sativa L.) by the effect of storage length on fungal invasion under different storage technique
(Journal of Pure and Applied Microbiology, 2016) Shakshi Singh; Asha Sinha
The incidence of seed-borne mycoflora in sahbhagi rice was screened by Agar plate method and Blotter method. Seed stored in different conditions like Bin and Gunny bag then observation was taken periodically 0, 3, 6, 9, 12 months in each storage condition. Surface sterilization was done by 0.1% mercuric chloride (HgCl2) solution. Both surface sterilized and unsterilized seeds were taken for isolation of fungi. A total number of 16 fungal species including Rhizopus stolonifer, Mucor hiemalis, Aspergillus flavus, A. Niger, A. candidus, A. fumigates, Penicillium rubrum, P. citrinum, Alternaria alternata, Drecshlera gramini, Curvularia lunata, Trichoderma harzianum, Microdochium lycopodinum, Fusarium oxysporum, Dark Sterile Mycelium and White Sterile Mycelium were found to be associated with the Sahabhagirice cultivar. Among them the most predominant seed-borne fungi, associated with seed were A. Niger (56.67% & 63.33%), A. flavus (53.33% & 56.67%), P. citrinum (50% & 53.33%) and M. lycopodinum (50% & 53.33%) by Agar plate method and A. Niger (50% & 56.67%), A. flavus (46.67% & 53.33%), P. citrinum (46.67% & 50%) and M. lycopodinum (46.67% & 50%) by Blotter method in Bin and Gunny Bag storage condition, respectively at the end of storage. Visual examination of seed showed that the maximum increase in the number of abnormal seed was recorded in gunny bag than Bin. Highest percent incidence of seed borne fungi was recorded in Gunny bag storage condition than Bin. In both storage procedures control seed yielded more number of seed-borne fungi as compared to sterilized seed during different storage period.
Influence of fungi on carbohydrate and phenol content of Jatropha curcas seeds during storage
(Journal of Pure and Applied Microbiology, 2014) Seweta Srivastava; Manisha Srivastava; Ravindra Kumar; Swapnil Kumar Shrivastava; Gorakh Nath Gupta; Asha Sinha
Jatropha curcas L. has been considered a potential source of seed oil for the production of biofuel. The aim of this study was to estimate the change in carbohydrate and phenolic content of Jatropha seeds after deterioration under storage condition. For estimation of carbohydrate and phenol fresh, stored as well as infested Jatropha seeds were used. Whole seed and kernels were infested with six dominant fungi viz. Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Fusarium chlamydosporum and Penicillium glabrum separately. Four different concentrations of seed samples viz. 50μl, 100μl, 150μl and 200μl were taken for the carbohydrate and phenol estimation of stored as well as infested Jatropha seeds. Carbohydrate content got reduced during storage while the phenolic content increases to show their antimicrobial effect. Maximum carbohydrate found was 50mg/ml at 200μl concentration in Fusarium chlamydosporum infested Jatropha seeds followed by Penicillium glabrum i.e., 30mg/ml and minimum carbohydrate content found was 1mg/ml at 50μl concentration in Aspergillus flavus infested Jatropha seeds and 4mg/ml in Aspergillus fumigatus at 50μl concentration in infested Jatropha kernels. Maximum Phenol content found was 190mg/100mg dry wt. in Fusarium chlamydosporum infested Jatropha kernels followed by Penicillium glabrum infested Jatropha seeds and kernels i.e., 180mg/100mg dry wt. at 200μl concentration while minimum phenol content was found nearly same i.e., 5.33mg/100mg dry wt. and 5.67mg/100mg dry wt. at 50μl and 100μl concentrations in fresh seeds, respectively.
Minimum inhibitory concentration of Thiram and Carbendazim on Aspergillus flavus (Link.) of groundnut
(2013) Parmanand Trivedi; Saurabh Singh; J. Mishra; Asha Sinha
The main aim of the present study was to enumerate the effect of fungicides on Aspergillus flavus (Link.) of groundnut. Chandra cultivar and two fungicides viz., Thiram and Carbendazim were selected for further study. Concentration of fungicides varying from 100-800 μg/ml with incubation period 1-8 days. The percentage inhibition of Aspergillus flavus was recorded using poison food technique in petriplate. Thiram was found to be having more inhibitory effect as compared to carbendazim.
Mycoflora Associated with Decomposition of Rice Stubble Mixed with Soil
(2008) Vibha Pandey; Asha Sinha
Fungi inhabiting rice stubble mixed with soil were isolated by dilution plate technique. Moisture content of decomposed rice stubble mixed with soil was 25.32% in the month of August and minimum (5.35%) in the month of April and pH varied between 6.8-7.2. The highest (47.68 x 104) fungal population in 1 g of rice stubble mixed with soil was recorded in the month of October and the lowest (16.88 x 104) in the month of May. A total of twenty-nine fungal species were recorded during the entire period of decomposition. Dueteromycetous fungi constituted 75.86 per cent of total fungal population followed by zygomycetous, oomycetous and ascomycetous fungi. Monthly variation in fungal population was correlated with substrate availability and climatic factors. Dominance of Rhizopus stolonifer, Aspergillus flavus and Trichoderma harzianum was recorded during the decomposition while Pestalotia mangiferae, Torula graminis and Alternaria solani were obtained as rare fungal species. © 2008, Versita. All rights reserved.
Physico-chemical properties of Jatropha curcas oil during storage
(Indian Society of Agricultural Biochemists, 2015) Seweta Srivastava; G.N. Gupta; Asha Sinha; Vandana Srivastava; Anchal Srivastava
Biodiesel is a renewable alternative fuel for the diesel engine derived from natural sources like Jatropha curcas oil. The present study was to estimate the changes that occur in physico-chemical properties of oils extracted from stored Jatropha seeds in comparison to fresh Jatropha seeds. Physico-chemical properties of Jatropha oil viz. acid value, iodine value, saponification value, UV spectroscopy, cetane value, refractive index, viscosity were estimated. All the values were higher in stored seed oil except iodine value which was lower than fresh seeds. The acid value, saponification value, refractive index and viscosity shows negative effect on the quality of Jatropha oil while decrease in iodine value and increase in cetane value is preferable for better quality bio-diesel. © 2015, Indian Society of Agricultural Biochemists. All rights reserved.
Screening of seed-borne mycoflora of Jatropha curcas L.
(2011) Seweta Srivastava; Asha Sinha; C.P. Srivastava
The aim of the present study was to check the deterioration of Jatropha curcas L. seeds during storage. Agar plate and standard blotter methods were used to study the seed-borne mycoflora of Jatropha curcas L. Both surface sterilized and unsterilized seeds were taken for isolation of fungi. Surface sterilization was done by 0.1% mercuric chloride (HgCl 2) solution. A significant contamination with fungal genera was detected in analyzed stored seeds. Sixteen fungal species with two strains of Aspergillus flavus i.e., brown and green were isolated from physic nut seeds during one year of storage. Fungi isolated and identified were Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Cephaliophora irregularis, Chaetomium globosum, Cladosporium cladosporioides, Curvularia lunata, Fusarium moniliforme, Fusarium roseum, Penicillium citrinum, Penicillium rubrum, Rhizopus stolonifer, Dark sterile mycelium and White sterile mycelium. This is the first report of Cephaliophora irregularis on Jatropha curcas L. seeds. Agar plate method showed better results for isolation of Chaetomium globosum, Cladosporium cladosporioides, Curvularia lunata and Fusarium moniliforme. © 2011 Academic Journals Inc.
Storage fungi and mycotoxins
(Springer Singapore, 2020) Shrvan Kumar; Asha Sinha; Ravindra Kumar; Vimla Singh; K.S. Hooda; Kedar Nath
Seed is the basic unit of crop production and has greater contribution to environmental and cultural factors and is widely distributed in national and international trade. The seeds are found to be responsible for disease transmission because they carry a number of pathogens. The toxigenic fungal flora, existing in conjunction with food, largely includes genera Aspergillus, Fusarium, and Penicillium and, to a lesser extent, the genera Alternaria, Claviceps, and Stachybotrys. These economically important species of fungi produce significant mycotoxins. More than 400 mycotoxins are known to exist in nature. Contamination of foods and feeds with mycotoxins is a worldwide serious problem. The most important mycotoxins in terms of toxic effect on both humans and animals are aflatoxins (AFs), citrinin (CIT), cyclopiazonic acid (CPA), fumonisins (FBs), moniliformin (MON), ochratoxin A (OTA), deoxynivalenol (DON), nivalenol (NIV), T-2 toxin (T-2), patulin (PAT), zearalenone (ZEA), and ustiloxins. These mycotoxins have several adverse impacts on consumers, such as loss of human and animal lives, health-care and veterinary care costs, contaminated food and feed disposal costs, and huge investment in research and management of the mycotoxin problem. The mycotoxins induce diverse biological effects, which have been characterized on animals and humans. These toxic effects of mycotoxins include cytotoxic, carcinogenic, immune suppressive, nephrotoxic neurotoxic, mutagenic and estrogenic effects, etc. © Springer Nature Singapore Pte Ltd. 2020.
Streptomyces rochei SM3 Induces Stress Tolerance in Chickpea Against Sclerotinia sclerotiorum and NaCl
(2015) Smita Srivastava; Jai Singh Patel; Harikesh Bahadur Singh; Asha Sinha; Birinchi Kumar Sarma
Understanding on actinomycetes-mediated stress tolerance in plants is very limited. This study demonstrated for the first time some stress tolerance mechanisms in chickpea via mediation of an actinomycetes strain Streptomyces rochei SM3. Here, we used the strain SM3 for treating chickpea seeds and plants raised from such seeds were challenged with Sclerotinia sclerotiorum and NaCl. Chickpea mortality due to Sc. sclerotiorum infection was suppressed by nearly 48%, and biomass accumulation was increased by nearly 20% in the salt-stressed condition in SM3-treated plants compared to non-treated plants. Physiological responses in chickpea under the challenging conditions showed that phenylalanine ammonia lyase activities increased in SM3-treated plants. This is followed by accumulation of higher concentrations of phenolics that led to enhanced lignifications in SM3-treated plants compared to non-SM3-treated plants challenged with the same stresses. Antioxidant activities, as assessed through catalase activities and proline accumulation, also increased in SM3-treated plants challenged with both the stresses compared to non-SM3-treated plants. Investigation at genetic level further showed that the strain SM3 triggered the ethylene (ET) responsive ERF transcription factor (CaTF2) under the challenged conditions. Thus, from this study, we conclude that actinomycetes St. rochei SM3 trigger the ET-mediated defence pathway in chickpea and activates the phenylpropanoid pathway for alleviating the stresses caused by Sc. sclerotiorum and salt in chickpea. © 2014 Blackwell Verlag GmbH.