- new delhi, india
- Scientist at NRRI, Cuttack, India.edit
Ascochyta blight of chickpea is caused by Ascochyta rabiei (Pass.) Labr. which is primarily seedborne. For rapid detection and precise identification of A. rabiei, a sequence-characterized amplified region (SCAR) marker was developed for... more
Ascochyta blight of chickpea is caused by Ascochyta rabiei (Pass.) Labr. which is primarily seedborne. For rapid detection and precise identification of A. rabiei, a sequence-characterized amplified region (SCAR) marker was developed for detection of genomic DNA and infected plant DNA. An SSR primer amplified monomorphic band was cloned in pGEM®-T easy vector and sequenced. The best primer pair was selected and validated on A. rabiei. The specificity and sensitivity of the SCAR-based marker designated as MBAR was evaluated using conventional PCR and real-time PCR. The marker produced consistently an amplicon size of 196 bp in all A. rabiei isolates tested. The sensitivity of the marker was 0.1 ng of genomic fungal DNA and 0.5 ng of plant DNA by conventional PCR and 0.5 pg of A. rabiei DNA and 1.0 pg of plant DNA by real-time PCR. This is the first SCAR marker having high specificity and sensitivity towards A. rabiei. The marker may be useful in detecting the pathogen before the disease appearance and in plant quarantine program to detect the pathogen in seed lots.
Research Interests:
Genetic diversity assessment and population structure analysis are essential for characterization of pathogens and their isolates. Markers are essential tools for exploring genetic variation among the isolates. False smut of rice caused... more
Genetic diversity assessment and population structure analysis are essential for characterization of pathogens and their isolates. Markers are essential tools for exploring genetic variation among the isolates. False smut of rice caused by Ustilaginoidea virens, formerly Villosiclava virens, is a major emerging disease of rice in India. A high level of variability is observed at the field level, but no information is available from India on genetic diversity and population structure. This is the first report of genetic diversity and population structure of U. virens from India that included 63 isolates distributed across the vast geographical area of eastern and north‐eastern India (18.9 to 26.7°N and 82.6 to 94.2°E). Seventeen RAPDs and 14 SSRs were identified as polymorphic and a total of 140 alleles were detected across the populations. The average number of alleles per locus for each primer was 4.5. All the isolates were grouped into two major clusters, with partial geographical segregation that was supported by principal coordinate analysis. Mantel test suggested genetic distance within the isolates increased with increasing geographical distance. Analysis of molecular variation showed more genetic variation within populations and less among populations. This outcome will help in understanding genetic diversity of U. virens from eastern and north‐eastern India and in planning effective management strategies.
Research Interests:
Research Interests:
Research Interests:
Ascochyta blight caused by Ascochyta rabiei is a serious disease of chickpea world wide. Twenty five Indian isolates of A. rabiei were evaluated for their morphological variability and 91 chickpea cultivars were screened for their... more
Ascochyta blight caused by Ascochyta rabiei is a serious disease of chickpea world wide. Twenty five Indian isolates of A. rabiei were evaluated for their morphological variability and 91 chickpea cultivars were screened for their reactions to Ascochyta blight. The populations of A. rabiei showed variations in various morphological characters like conidia size and density, colony colour and growth rate. Colonies of the isolates on artificial media were flat, submerged with sparse mycelium. The mycelium was pale cream at first but later turned greyish white or green to greenish dark. In Chickpea dextrose agar (CDA) medium, the isolate AR1 (Delhi) grew the largest followed by the isolates AR14 (Punjab), AR5 (Himachal Pradesh), AR9 (Jammu and Kashmir) and AR20 (Rajasthan) with statistically similar colony diameter at 20 days after incubation. Thus, the growth rate was significantly highest in isolate AR1 (Delhi) followed by the isolates AR14 (Punjab), AR5 (Himachal Pradesh), AR9 (Jammu and Kashmir), and AR20 (Rajasthan). More or less similar growth patterns of the isolates were observed on PDA medium with comparatively less growth as compared to CDA. The size of the conidia in all the isolates ranged from 9.19–12.51 x 3.36–4.32 μm whereas the density of conidia in A. rabiei isolates ranged from 0.5–7.2 x 106 conidia ml−1. Three cultivars namely, ICC 76, ICC 3996 and ICC 15978were identified as highly resistant to Ascochyta blight. Thirty cultivars showed resistant and 14 cultivars showed moderately resistant reactions against the disease. These cultivars may be used for cultivation or resistant breeding programs.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Background Rice (Oryza sativa) is one of the most dominating cereal crop and half of the global people have chosen it as staple food. Rice production has increased significantly but the productivity is not increased significantly to... more
Background Rice (Oryza sativa) is one of the most dominating cereal crop and half of the global people have chosen it as staple food. Rice production has increased significantly but the productivity is not increased significantly to combat the global need. One of the major constraints of low productivity is biotic stresses faced by rice growers. Some of the important biotic stresses of rice are major diseases like brown spot, bacterial blight, blast, sheath blight and, few emerging but significant diseases like false smut, bakanae and sheath rot play crucial role in reducing yield per unit area and quality of rice. Host plant resistance is the most effective, economic and eco-friendly approach of mitigating disease like biotic stress problem. Objective The objective of this review is to compile data related to resistance in rice against various major and emerging diseases as well as their application to develop gene pyramided varieties that increase resistance to those pathogens to ...
Research Interests:
Rice false smut caused by Ustilaginoidea virens is a destructive inflorescence disease threatening rice production worldwide. The disease is emerging in many rice growing countries including India. Estimation of yield loss helps to... more
Rice false smut caused by Ustilaginoidea virens is a destructive inflorescence disease threatening rice production worldwide. The disease is emerging in many rice growing countries including India. Estimation of yield loss helps to understand the importance of the disease and hence appropriate measures for its management may be devised. Therefore, an investigation was conducted in farmers' field of Odisha during kharif 2017. The disease incidence, chaffiness and yield loss for 20 rice genotypes were assessed following a standard method. Disease severity was calculated based on the number of smut ball in an infected panicle. False smut incidence varied from 6-33% while the disease severity ranged from 0.33-17.25% in different genotypes. The highest disease incidence was observed in Pooja (33.33%) followed by Varsha Dhan (16.67%) and Sarala (13.89%). The highest disease severity was observed in Pooja (17.25%) followed by Utkal Prava (10.46%) and Moti (8.89%). The healthy panicles ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Different isolates of Ustilaginoidea virens showed variation in the size, colour and shape of the conidia, length of spines and width of the hyphae. The conidia were globose, irregularly round to elliptical and warty on the surface with... more
Different isolates of Ustilaginoidea virens showed variation in the size, colour and shape of the conidia, length of spines and width of the hyphae. The conidia were globose, irregularly round to elliptical and warty on the surface with diameters ranging from 4.20 to 6.54 µm. The scanning electron microscopy revealed that the conidial wall was echinulated and ornamented with prominent spines. The spines were pointed at the apex or irregularly curved and ranged from 359.9- 994.5 nm long. Based on colony characters isolates of U. virens were grouped into three groups. The maximum colony diameter was observed in isolate UV3 (40 mm) while minimum was in UV7 (25 mm). The width of the hyphae in different isolates varied from 1.26-2.81 µm. The maximum width of the hypha was 2.81 µm in UV4 isolate and minimum in UV3 (1.26 µm). The genetic diversity of the eight isolates of U. virens, by random amplified polymorphic DNA (RAPD) marker using nine primers, revealed a considerable level of genet...
Research Interests:
Traditional agricultural practices exclusively based on the synthetic fertilizers and pesticides. Although chemicals show promising results in crop management, there are several major issues concerning pesticide residues, human health... more
Traditional agricultural practices exclusively based on the synthetic fertilizers and pesticides. Although chemicals show promising results in crop management, there are several major issues concerning pesticide residues, human health predicaments and environmental pollution. To minimize these effects, an alternative approaches are highly essential. One such approach is the utilization of beneficial microbes residing in the plant rhizosphere. Among Plant Growth Promoting Rhizobacteria (PGPRs), the sporulating Gram-positive bacteria like Bacillus spp. have been well studied, especially production of versatile antibiotics, lytic enzymes, antagonistic effect, plant growth promotion and induction of systemic resistance. Despite this, only less information is available for their effect on crop production. Many Bacilli rhizobacteria and their multifaceted benefits are still unexploited. This chapter will give an overview of the Bacilli rhizobacteria and their multifarious benefits for agricultural sustainability and environmental safety.
Research Interests:
This study is a unique report of the utilization of Trichoderma strains collected from even tree barks for rice plant growth, its health management, and paddy straw degradation. Seven different spp. of Trichoderma were characterized... more
This study is a unique report of the utilization of Trichoderma strains collected from even tree barks for rice plant growth, its health management, and paddy straw degradation. Seven different spp. of Trichoderma were characterized according to morphological and molecular tools. Two of the isolated strains, namely Trichoderma hebeiensis and Trichoderma erinaceum, outperformed the other strains. Both of the strains controlled four important rice pathogens, i.e., Rhizoctonia solani (100%), Sclerotium oryzae (84.17%), Sclerotium rolfsii (66.67%), and Sclerotium delphinii (76.25%). Seed bio-priming with respective Trichoderma strains reduced the mean germination time, enhanced the seedling vigor and total chlorophyll content which could be related to the higher yield observed in two rice varieties; Annapurna and Satabdi. All the seven strains accelerated the decomposition of rice straw by producing higher straw degrading enzymes like total cellulase (0.97–2.59 IU/mL), endoglucanase (0....
Research Interests: Horticulture, Biology, Medicine, Cellulase, Trichoderma, and 3 moreSclerotium, Polyphenol Oxidase, and Shoot
Research Interests:
Research Interests:
The present investigation was carried out to asses the incidence of bakanae disease in Odisha, characterization of the isolates and its management with fungicides. The disease incidence ranging from 1–25.50 percent on different rice... more
The present investigation was carried out to asses the incidence of bakanae disease in Odisha, characterization of the isolates and its management with fungicides. The disease incidence ranging from 1–25.50 percent on different rice varieties was recorded in five districts mainly, Cuttack, Sambalpur, Bargarh, Ganjam and Jajpur. These regions were identified as new hot spots for the disease. The disease was observed to a significant extent in most of the commercially growing varieties with maximum disease incidence on Pooja (19.0% and 24.5% respectively for two seasons). A significant variation was observed among the isolates with respect to cultural, morphological characters and degree of pathogenicity. All the ten isolates were grouped into highly virulent group. The amplification of tef-1alpha gene generated approx 700 bp bands. In phylogenetic analysis, based on tef-1alpha gene region, overall two major groups were formed. The F.fujikuroi isolates FJ1 (Kisannagar), FJ2 (Khurda), FJ3 (Tangi-Chodwar) and FJ9 (Chandikole) belonged to same group whereas FJ4 (Cuttack), FJ5 (Jajpur), FJ6 (Kisannagar-2), FJ7 (Sambalpur), FJ8 (Bargarh) and FJ10 (Ganjam) are in a separate group with other world isolates. Among the ten systemic fungicides tested, all found effective with 100 percent reduction in mycelial growth. All the three tested Trichoderma spp. were found effective under in vitro with complete inhibition and lyses of the pathogen mycelium. Seed treatment with Carbendazim 50% WP @1 g/kg of seeds found effective with maximum germination, vigor index and disease reduction.
Research Interests: Biology and Pathogenicity
Research Interests:
Abstract The technique of proteome analysis using two-dimensional polyacrylamide gel electrophoresis (2 d -PAGE) has the power to monitor global changes that occur at protein level in sub-cellular compartments. Analysis of proteins... more
Abstract The technique of proteome analysis using two-dimensional polyacrylamide gel electrophoresis (2 d -PAGE) has the power to monitor global changes that occur at protein level in sub-cellular compartments. Analysis of proteins expressed in rhizobacteria treated crop plants will give us an idea about the plant growth promoting rhizobacteria (PGPR) mediated induced gene expression in plants against pathogen attack. In addition, proteomic studies provide the basic knowledge on the gene(s) and pathways induced during host-PGPR interaction. Proteome analysis linked to genome sequence information is very useful for functional genomics by giving information on alternate splicing or post translational modification. This chapter was designed to clearly understand the interaction between host-pathogen-bioagent in crop plants.
Research Interests: Computational Biology, Biology, Proteomics, Pathogen, Gene, and 3 moreRhizobacteria, Proteome, and Academic
Research Interests:
Research Interests:
Research Interests:
Availability of resistance sources among cultivated varieties helps in easy utilization as donor owing to no deleterious linkage drag. In the present investigation, 121 rice varieties were screened for their resistance against a virulent... more
Availability of resistance sources among cultivated varieties helps in easy utilization as donor owing to no deleterious linkage drag. In the present investigation, 121 rice varieties were screened for their resistance against a virulent isolate of Fusarium fujikuroi (Ff-10) and genotyped using reported microsatellite markers. Among 121 varieties, only eight varieties, namely Luna Sankhi, Improved Tapaswini, Sarasa, Sadabahar, CR-311, Kshira, Wifa-10 and Binadhan-8, were found to be highly resistant (HR), seven varieties were resistant (R), 31 were moderately resistant (MR), 10 were moderately susceptible (MS), 11 were susceptible (S) and the rest 54 were highly susceptible (HS). The allele diversity of molecular markers classified the population into three clusters. The highly resistant varieties were grouped in major clusters II and III, whereas the remaining genotypes were distributed in all three clusters. Analysis of molecular variance (AMOVA) resulted in 95% of the maximum diversity within the test population and 5% diversity between populations. Population structure analysis grouped the genotypes into two sub-populations based on relatedness, where most of the resistant genotypes were grouped into one sub-population and other genotypes were distributed among sub-populations. Re-examination of reported markers' trait associations with bakanae resistance in the experimental population identified marker RM-3698 as associated with resistance accounting 8.4% explained phenotypic variation. This study shows that simple sequence repeat markers can be used to assess allelic diversity and population structure of bakanae resistance in rice varieties. The highly resistant genotypes, along with resistance markers, could be used as donors in marker-assisted bakanae improvement breeding programmes.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Rice (Oryza sativa L) being one of the imperative food crops of the word contributes immensely to the food and nutritional security of India. The cultivation of rice is changed over the decades from a simple cultivation practices to the... more
Rice (Oryza sativa L) being one of the imperative food crops of the word contributes immensely to the food and nutritional security of India. The cultivation of rice is changed over the decades from a simple cultivation practices to the advanced cultivation to increase yield. Increased in rice yields especially after 1960s is mainly due to the introduction of high yielding semi-dwarf varieties which requires more inputs like chemical fertilizers, water and other resources. As a result, India achieved self sufficiency in rice and currently producing more than 115 MT of rice to meet country’s demand. Now India is exporting rice to other nations and earning foreign returns. With the change in rice cultivation practices, problems also aroused side by side. A number of biotic and abiotic stresses emerged as major constraints for rice cultivation in diverse agro-climatic conditions and growing ecologies. Diseases are the major biotic constraints to rice which can reduce the yields by 20–1...
Research Interests:
Research Interests:
Aim: To assess yield loss in different rice varieties due to rice bakanae disease and to understand the role of weather parameters on disease incidence and losses. Methodology: Roving survey and surveillance was carried out for three... more
Aim: To assess yield loss in different rice varieties due to rice bakanae disease and to understand the role of weather parameters on disease incidence and losses. Methodology: Roving survey and surveillance was carried out for three consecutive years to assess the status of rice bakanae disease among twenty popular rice varieties growing in Eastern India. Field experiment was conducted for three successive years, i.e., 2016, 2017 and 2018 at Cuttack. Highly susceptible variety Pooja was selected for the experiment. Data on disease incidence was collected daily from 10 days after transplanting to harvesting stage and data were recorded at standard meteorological week. Correlation was performed to find the effect of different weather parameters on the incidence of bakanae disease on rice. Results: Disease being seed borne caused significant reduction in yield and quality. The maximum disease incidence was recorded in Pooja with 18.25, 28.50 and 40.25 per cent in three years. The same...
Research Interests:
Research Interests:
Research Interests:
False smut caused by Ustilaginoidea virens is currently an important disease of rice. The disease regularly occurs in many parts of India resulting in significant economic losses. To find an eco-friendly method of false smut management,... more
False smut caused by Ustilaginoidea virens is currently an important disease of rice. The disease regularly occurs in many parts of India resulting in significant economic losses. To find an eco-friendly method of false smut management, the effect of staggered rice sowing and flowering on false smut incidence were evaluated in 2018 and 2019 seasons. Six rice varieties were sown at 15-day intervals from 24th May to 20th August in both the years. Most varieties developed false smut when their flowering occurred during September and October in both seasons of 2018 and 2019 irrespective of their sowing dates. The relative humidity showed positive correlation with Pooja and Sarala but negatively correlated with Anjali , Durga , Geetanjali and Naveen . Therefore, avoiding the flowering period during the critical months can considerably limit the false smut severity and help to manage the disease.
Research Interests:
False smut disease is caused by Ustilaginoidea virens (Cooke) Takahashi on rice. It has become a serious pathogen in almost all rice-growing areas in the world. The conditions for successful isolation of pathogen in axenic cultures have... more
False smut disease is caused by Ustilaginoidea virens (Cooke) Takahashi on rice. It has become a serious
pathogen in almost all rice-growing areas in the world. The conditions for successful isolation of pathogen in axenic cultures
have been standardized and the growth conditions were optimized. The fastest growth rate was achieved with potato sucrose
agar medium having a pH of 6.0 at an incubation temperature of 27°C. Dark incubation was also found highly conducive for
the growth of fungus compared to incubation in light. These conditions could be useful for the best isolation of the pathogen
for different studies. Beside morphological identification, the identity of the fungal pathogen was confirmed through ITS
sequencing which showed up to 98 % identity with U. virens in NCBI-BLAST analysis. The proposed isolation technique
coupled with information on optimization of culture conditions of U. virens will immensely contribute to further studies on
this fungus and the disease in India.
pathogen in almost all rice-growing areas in the world. The conditions for successful isolation of pathogen in axenic cultures
have been standardized and the growth conditions were optimized. The fastest growth rate was achieved with potato sucrose
agar medium having a pH of 6.0 at an incubation temperature of 27°C. Dark incubation was also found highly conducive for
the growth of fungus compared to incubation in light. These conditions could be useful for the best isolation of the pathogen
for different studies. Beside morphological identification, the identity of the fungal pathogen was confirmed through ITS
sequencing which showed up to 98 % identity with U. virens in NCBI-BLAST analysis. The proposed isolation technique
coupled with information on optimization of culture conditions of U. virens will immensely contribute to further studies on
this fungus and the disease in India.
Different isolates of Ustilaginoidea virens showed variation in the size, colour and shape of the conidia, length of spines and width of the hyphae. The conidia were globose, irregularly round to elliptical and warty on the surface with... more
Different isolates of Ustilaginoidea virens showed variation in the size, colour and shape of the conidia, length
of spines and width of the hyphae. The conidia were globose, irregularly round to elliptical and warty on the surface with
diameters ranging from 4.20 to 6.54 μm. The scanning electron microscopy revealed that the conidial wall was echinulated
and ornamented with prominent spines. The spines were pointed at the apex or irregularly curved and ranged from 359.9–
994.5 nm long. Based on colony characters isolates of U. virens were grouped into three groups. The maximum colony
diameter was observed in isolate UV3 (40 mm) while minimum was in UV7 (25 mm). The width of the hyphae in different
isolates varied from 1.26-2.81 μm. The maximum width of the hypha was 2.81 μm in UV4 isolate and minimum in UV3 (1.26
μm). The genetic diversity of the eight isolates of U. virens, by random amplified polymorphic DNA (RAPD) marker using
nine primers, revealed a considerable level of genetic variation. The dendrogram showed two main clusters; cluster I
comprised of five isolates (UV1, UV5, UV8, UV6 and UV7), while Cluster II consisted of three isolates (UV2, UV3 and UV4).
of spines and width of the hyphae. The conidia were globose, irregularly round to elliptical and warty on the surface with
diameters ranging from 4.20 to 6.54 μm. The scanning electron microscopy revealed that the conidial wall was echinulated
and ornamented with prominent spines. The spines were pointed at the apex or irregularly curved and ranged from 359.9–
994.5 nm long. Based on colony characters isolates of U. virens were grouped into three groups. The maximum colony
diameter was observed in isolate UV3 (40 mm) while minimum was in UV7 (25 mm). The width of the hyphae in different
isolates varied from 1.26-2.81 μm. The maximum width of the hypha was 2.81 μm in UV4 isolate and minimum in UV3 (1.26
μm). The genetic diversity of the eight isolates of U. virens, by random amplified polymorphic DNA (RAPD) marker using
nine primers, revealed a considerable level of genetic variation. The dendrogram showed two main clusters; cluster I
comprised of five isolates (UV1, UV5, UV8, UV6 and UV7), while Cluster II consisted of three isolates (UV2, UV3 and UV4).