Browsing by Author "R.K. Jaiswal"

Now showing 1 - 7 of 7

Biomass of nematode and associated roots: A determinant of symptom production in root knot disease of rice (Oryza sativa L.)
(2006) K.P. Singh; R.K. Jaiswal; N. Kumar; D. Kumar
The biomass of Meloidogyne graminicola developing in rice roots was studied in relation to the expression of disease symptoms. The biomass of invading second stage juveniles (0.09 μg) increased to 33 μg on day 16 when adult females were in advance egg laying stage, with an increase of approximately 360-fold. Initiation of leaf yellowing was related to the ratio between total nematode and total root biomass of rice seedlings. Plants with nematode-to-root biomass ratios above 1:161 did not show any symptom while those with ratios between 1:138 and 1:121 exhibited yellowing. Plants with nematode-to-root biomass ratios between 1:115 and 1:60 showed moderate stunting while those with ratios between 1:43 and 1:20 exhibited severe stunting. The wilting symptoms occurred at or below 1:14 nematode-to-root biomass ratio. The yellowing of leaves in seedlings inoculated with graded inocula was expressed when the nematode-to-root biomass ratios reached to 1:136 on day 15 at 1000 J 2, 1:138 on day 9 at 3000 J2, 1:134 on day 7 at 6000 J2 and 1:129 on day 5 at 9000 J2 per pot. In rice nurseries, seedlings showing moderate stunting, severe stunting, wilting and wilting with single gall recorded nematode-to-root biomass ratios of 1:92, 1:20, 1:12 and 1:14 respectively. In severely stunted transplanted rice, the nematode-to-root biomass ratio ranged from 1:84 to 1:75. © 2006 The Authors.
Can endophytic Arthrobotrys oligospora modulate accumulation of defence related biomolecules and induced systemic resistance in tomato (Lycopersicon esculentum Mill.) against root knot disease caused by Meloidogyne incognita
(2013) Udai B. Singh; Asha Sahu; Nisha Sahu; Bhanu P. Singh; R.K. Singh; Renu; Dhananjaya P. Singh; R.K. Jaiswal; B.K. Sarma; H.B. Singh; M.C. Manna; A. Subba Rao; S. Rajendra Prasad
The soil community is an often ignored part of research which links plant biodiversity and ecosystem functioning despite their influence on numerous functions such as decomposition and nutrient cycling. Few consistent patterns have been detected that link plant and soil community composition; however, it has not been studied in details. Arthrobotrys oligospora, a model predacious fungus for nematode trapping, beside biocontrol potential may modulate plant health and increase natural antioxidants in tomato fruit directly or indirectly. In the present study we have investigated the effects of nematode trapping fungus A. oligospora on induction and bioaccumulation of natural antioxidant and defence related biomolecules in tomato plants when challenged with Meloidogyne incognita causing root knot. Endophytic and rhizospheric isolates of A. oligospora were isolated from different parts of India and characterized under controlled laboratory conditions. The study describes the multifarious effects of endophytic and rhizospheric isolates of A. oligospora in green house and field conditions in tomato plants when inoculated individually or in combination. It was found that A. oligospora EAO-147 and RST-101 when applied individually or in combination significantly increased various attributes in plants. Among both the isolates, endophytic A. oligospora EAO-147 was found to be more potential in enhancing the defence related biomolecules, enzymes and exhibited biocontrol potentials against M. incognita. With application of A. oligospora, increase in nutritional quality of ripe tomato fruits (mineral nutrients and natural antioxidant properties) was also demonstrated first time. Results suggest that application of A. oligospora, particularly endophytic, not only helps in control of nematodes but also increase plant growth as well as enhances the nutritional value of tomato fruits. Thus, it proves to be an excellent biocontrol as well as plant growth promoting agent. © 2012 Elsevier B.V.
Catenaria anguillulae Sorokin: A natural biocontrol agent of Meloidogyne graminicola causing root knot disease of rice (Oryza sativa L.)
(2007) K.P. Singh; R.K. Jaiswal; Niranjan Kumar
Catenaria anguillulae parasitized and killed the eggs and second stage juveniles (J2) of Meloidogyne graminicola under natural conditions. The percentage of infection in eggs was higher than J2 of M. graminicola, which ranged between 0-50.3% and 0-18.9% in 2004 and 0-46.6% and 0-21.7% in 2005, respectively. The higher parasitism of eggs and J2 was recorded from those fields in which plants were severely infected with M. graminicola. The degree of parasitism of eggs and J2 by C. anguillulae varied with severity of root knot disease. The fields with a higher root gall index recorded a higher percentage of infection in eggs and J 2 of M. graminicola. In general, old galls when teased and incubated, recorded higher parasitism of eggs and juveniles than young galls. © 2006 Springer Science+Business Media B.V.
Model coupling approach for daily runoff simulation in Hamp Pandariya catchment of Chhattisgarh state in India
(Springer Science and Business Media B.V., 2022) Gaurav Singh; A.R.S. Kumar; R.K. Jaiswal; Surjeet Singh; R.M. Singh
Runoff estimation is of immense importance in hydrological analysis for water resource planning and management. The developing countries cannot afford to establish a large number of gauging sites due to huge initial and operating expenditures. Hydrological modelling is an alternative solution to simulate the catchment response to extreme events under climate change for taking preventive measures. The hydrological models have their own leads and constraints, so because of limited hydrological data availability of the catchment, wavelet neural network (WNN), artificial neural network, adaptive neuro-fuzzy inference system, and Mike-11 Nedbor Afstromnings models were used in this study. These models were calibrated and validated using daily rainfall and runoff observations taken at Hamp Pandariya gauging station on Hamp river in the Chhattisgarh state of India. A comparative study of these models was carried out to investigate their performance, efficiency, and suitability for daily runoff simulation in Hamp Pandariya catchment and found suitable in simulating the hydrological response of the catchment and predicting runoff with a high degree of accuracy. The performance of these models was evaluated and compared with the aid of multiple goodness of fit criteria including coefficient of determinations (r2), Nash–Sutcliffe model efficiency index (NS), root mean square error, and water balance for model calibration and validation. These parameters indicated good agreement between observed and simulated runoff in terms of time to peak, discharge rate, daily and accumulated runoff volume, and shape of the hydrograph. The WNN was found the most appropriate model for future application due to Nash–Sutcliffe efficiency (NS) of 97% and 98% in calibration and validation, respectively, and the coefficient of determination as 99% both in calibration and validation. © 2021, The Author(s), under exclusive licence to Springer Nature B.V.
Nematophagous fungi associated with root galls of rice caused by Meloidogyne graminicola and its control by Arthrobotrys dactyloides and Dactylaria brochopaga
(2007) K.P. Singh; R.K. Jaiswal; N. Kumar; D. Kumar
Root galls of rice caused by Meloidogyne graminicola were examined for natural colonization by nematophagous fungi from four fields with different nematode infestations. Old galls from severely infested fields had a higher frequency of Monacrosporium eudermatum and Stylopaga hadra than young galls. The frequency of Arthrobotrys oligospora, Arthrobotrys dactyloides, Dactylaria brochopaga and Monacrosporium gephyropagum was lower. A greater proportion (%) of root galls were colonized by nematophagous fungi in those fields in which rice roots had a greater root gall index. This indicated that disease severity supported the colonization of galls by nematophagous fungi. In vitro predacity tests of four fungi showed that A. dactyloides was most effective in capturing and killing J2 of Mel. graminicola followed by D. brochopaga and Mon. eudermatum. Application of inocula of A. dactyloides and D. brochopaga in soil infested with Mel. graminicola, respectively, reduced the number of root galls by 86% and of females by 94%, and eggs and juveniles by 94%. The application of these fungi to soil increased plant growth: shoot length by 42.7% and 39.8%, root length by 45.5% and 48.9%, fresh weight of shoot by 59.9% and 56.7% and fresh weight of root by 20.3% and 25.1%, respectively, compared to these parameters for plants grown in nematode-infested soil. © 2007 The Authors.
Nematophagous fungi: Catenaria anguillulae and Dactylaria brochopaga from seed galls as potential biocontrol agents of Anguina tritici and Meloidogyne graminicola in wheat (Triticum aestivum L.)
(2013) Udai B. Singh; Asha Sahu; Nisha Sahu; R.K. Singh; Renu; Dinesh K. Singh; Bhanu P. Singh; R.K. Jaiswal; Dhananjaya P. Singh; J.P. Rai; M.C. Manna; K.P. Singh; J.S. Srivastava; A. Subba Rao; S. Rajendra Prasad
During the course of our investigation on the selective isolation and in vitro pathogenicity tests of the nematode egg parasite and endoparasitic Catenaria anguillulae and the nematode-trapping fungus Dactylaria brochopaga against Anguina tritici, and Meloidogyne graminicola, the two biocontrol agents were also examined for their capabilities to colonize wheat seed gall and also to reduce the M. graminicola, and A. tritici in wheat (Triticum aestivum L.). Using seed galls as bait was found effective for isolating the soilborne natural colonizers of seed galls of wheat caused by A. tritici. Seed galls were found severely infested with cellulose decomposers as well as nematode trapping fungi i.e., Fusarium spp. ., Verticillium spp., Aspergillus spp., Penicillium spp. Arthrobotrys oligospora, Arthrobotrys superba, Arthrobotrys dactyloides, Arthrobotrys musiformis, D. brochopaga, Monacrosporium eudermatum, Stylopaga hadra, Paecilomyces spp., and C. anguillulae. Co-inoculation of D. brochopaga DBS-105, and C. anguillulae CAS101 significantly reduced the root knot and seed gall in wheat and increased the plant growth parameters including length, and dry weight of root and shoot as well as yield attributing characters like spike length; number of seed per spike, test weight etc. under greenhouse conditions as compared to pathogen challenged plants without any bioagents/chemical nematicide. These bioagents have the potential to enhance production of quality seeds of wheat being free from hazardous pesticides and thus, can further be developed into marketable formulations in order to promote eco-friendly and sustainable means of crop production. © 2013 Elsevier Inc.
Priority Assessment of Sub-watershed Based on Optimum Number of Parameters Using Fuzzy-AHP Decision Support System in the Environment of RS and GIS
(Springer, 2019) C.D. Mishra; R.K. Jaiswal; A.K. Nema; V.K. Chandola; Arpit Chouksey
Identification for planning of land and water resource management based on efficient decision-making tool is very important for providing appropriate weightage in stressed site. In the present study, fuzzy analytical hierarchy process (FAHP) with different erosion hazards parameters (EHPs) have been used as a pronouncement for identification of naturally stressed sub-watershed in Nagwan watershed of Hazaribagh district in Jharkhand, India. In fuzzy-AHP, analytical hierarchy process (AHP) builds a hierarchy (ranking) of decision items using comparisons between each pair of items expressed as a matrix with fuzziness. Paired comparisons produce weighting scores that measure how much importance items and criteria have with each other and checking the consistency of the decision. In this study, the Nagwan watershed was divided in 21 sub-watershed which varies from 2.34 to 7 km 2 and all EHPs of sub-watersheds have been computed using remote sensing and GIS. From the study, it has been observed that best consistency ratio has been found when using 13 parameters that is 9.44 with narrow trapezoidal shape. Each morphometric parameter was ranked with respect to the value and weightage obtained by deriving the relationships between the morphometric parameters obtained through classification of the SW by associating the strength of fuzzy analytical hierarchy processes (FAHP). By this weight, the results revealed that the priorities in five categories, out of 21 sub-watershed 19 and 24% sub-watersheds qualify for very high and high priority, whereas 57% sub-watersheds fall under medium, low and very low priority. © 2018, Indian Society of Remote Sensing.