Ashok Kumar

Dr. Ashok Kumar


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 January 2022 in Frontiers in Plant Science
Verified
Journal Article
Open access
KTKuldeep Tripathi
Kuldeep Tripathi
JKJyoti Kumari
Jyoti Kumari
PGPadmavati G. Gore
Padmavati G. Gore
DMDwijesh C. Mishra
Dwijesh C. Mishra
ASAmit Kumar Singh
Amit Kumar Singh
ASAshutosh Sarker
Ashutosh Sarker
Lentil (Lens culinaris Medik.) is one of the major cool-season pulse crops worldwide. Its increasing demand as a staple pulse has led to the unlocking of diverse germplasm collections conserved in the genebanks to develop its superior varieties. The Indian National Genebank, housed at the Indian Council of Agricultural Research (ICAR)-National Bureau of Plant Genetic Resources, New Delhi, India, currently has 2,324 accessions comprising 1,796 indigenous and 528 exotic collections. This study was conducted to unveil the potential of lentil germplasm by assessing its agro-morphological characteristics and diversity, identifying trait-specific germplasm, and developing a core set. The complete germplasm set was characterized for two years, i.e., 2017–2018 and 2018–2019, and data were recorded on 26 agro-morphological traits. High phenotypic variability was observed for nine quantitative and 17 qualitative traits. A core set comprising 170 accessions (137 Indian and 33 exotic) was derived based on the characterization data as well as geographical origin using a heuristic method and PowerCore software. This core set was found to be sufficiently diverse and representative of the entire collection based on the comparison made using Shannon–Weaver diversity indices and χ2 test. These results were further validated by summary statistics. The core set displayed high genetic diversity as evident from a higher coefficient of variance in comparison to the entire set for individual traits and overall Shannon–Weaver diversity indices (entire: 1.054; core: 1.361). In addition, the total variation explained by the first three principal components was higher in the core set (70.69%) than in the entire collection (68.03%). Further, the conservation of pairwise correlation values among descriptors in the entire and core set reflected the maintenance of the structure of the whole set. Based on the results, this core set is believed to represent the entire collection, completely. Therefore, it constitutes a potential set of germplasm that can be used in the genetic enhancement of lentils.

9 November 2021 in Plants
Verified
Journal Article
Open access
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SPSwati Priya
Swati Priya
RBRuchi Bansal
Ruchi Bansal
GKGaurav Kumar
Gaurav Kumar
Dr. Harsh Kumar DikshitDr. Harsh Kumar Dikshit
Dr. Harsh Kumar Dikshit
JKJyoti Kumari
Jyoti Kumari
AKAshok Kumar
Ashok Kumar
Drought is the most critical environmental factor across the continents affecting food security. Roots are the prime organs for water and nutrient uptake. Fine tuning between water uptake, efficient use and loss determines the genotypic response to water limitations. Targeted breeding for root system architecture needs to be explored to improve water use efficiency in legumes. Hence, the present study was designed to explore root system architecture in lentil germplasm in response to drought. A set of 119 lentil (Lens culinaris Medik.) genotypes was screened in controlled conditions to assess the variability in root traits in relation to drought tolerance at seedling stage. We reported significant variation for different root traits in lentil germplasm. Total root length, surface area, root volume and root diameter were correlated to the survival and growth under drought. Among the studied genotypes, the stress tolerance index varied 0.19–1.0 for survival and 0.09–0.90 for biomass. Based on seedling survival and biomass under control and drought conditions, 11 drought tolerant genotypes were identified, which may be investigated further at a physiological and molecular level for the identification of the genes involved in drought tolerance. Identified lines may also be utilised in a lentil breeding program.

9 December 2020 in Plants
Verified
Journal Article
Open access
PDF file
RKRamesh Kumar
Ramesh Kumar
CKChavlesh Kumar
Chavlesh Kumar
RPRitu Paliwal
Ritu Paliwal
DCDebjani Roy Roy Choudhury
Debjani Roy Roy Choudhury
ISIsha Singh
Isha Singh
RSRakesh Singh
Rakesh Singh
Kalmegh (Andrographis paniculata (Burm. F.) Nees) is one of the most important medicinal plants and has been widely explored as traditional medicine. To exploit its natural genetic diversity and initiations of molecular breeding to develop novel cultivars or varieties, developments of genomic resources are essential. Four microsatellite-enriched genomic libraries—(CT)14, (GT)12, (AG)15 and (AAC)8—were constructed using the genomic DNA of A. paniculata. Initially, 183 recombinant colonies were screened for the presence of CT, GT, AG, and AAC microsatellite repeats, out of which 47 clones found positive for the desired simple sequence repeats (SSRs). It was found that few colonies had more than one desirable SSR. Thus, a sum of 67 SSRs were designed and synthesized for their validation among 42 A. paniculata accessions. Out of the 67 SSRs used for genotyping, only 41 were found to be polymorphic. The developed set of g-SSR markers showed substantial genetic variability among the selected A. paniculata accessions, with an average polymorphic information content (PIC) value of 0.32. Neighbor-joining tree analysis, population structure analysis, analysis of molecular variance (AMOVA), and principal coordinate analysis (PCoA) illustrated the considerable genetic diversity among them. The novel g-SSR markers developed in the present study could be important genomic resources for future applications in A. paniculata.

5 November 2022 in Genes
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Journal Article
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RPRitu Paliwal
Ritu Paliwal
RSRakesh Singh
Rakesh Singh
DCDebjani Roy Roy Choudhury
Debjani Roy Roy Choudhury
GTGunjan Tiwari
Gunjan Tiwari
AKAshok Kumar
Ashok Kumar
RMRita Singh Majumdar
Rita Singh Majumdar
In the present study, novel genomic-SSR (g-SSR) markers generated in our laboratory were used to characterize Tinospora cordifolia and related species. The g-SSR marker was also compared with EST-SSR and SCoT markers used earlier in our laboratory to assess the genetic diversity of T. cordifolia. A total of 26 accessions of T. cordifolia and 1 accession each of Tinospora rumphii and Tinospora sinensis were characterized using 65 novel g-SSR markers. A total of 125 alleles were detected with 49 polymorphic g-SSR markers. The number of alleles per locus varied from 1–4 with a mean value of 2.55 alleles per locus. Mean PIC, gene diversity, and heterozygosity were estimated to be 0.33, 0.41, and 0.65, respectively. The two species, namely T. rumphii and T. sinensis, showed cross-species transferability of g-SSRs developed in T. cordifolia. The success rate of cross-species transferability in T. rumphii was 95.3% and 93.8% in T. sinensis, proving the usefulness of this marker in genetic diversity studies of related species. The Tinospora accessions were also used for molecular characterization using SCoT and EST-SSR markers and compared for genetic diversity and cross-species transferability. The PIC, gene diversity, heterozygosity, and principal coordinate analysis showed that g-SSR is the better maker for a genetic diversity study of T. cordifolia. Additionally, high cross-species transferability of g-SSRs was found (95.3% and 93.8%) compared to EST-SSRs (68.8% and 67.7%) in T. rumphii and T. sinensis, respectively.

24 December 2019 in Plant Molecular Biology Reporter
Verified
Journal Article
Closed access
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DSDharmendra Singh
Dharmendra Singh
CSChandan Kumar Singh
Chandan Kumar Singh
KTKishor U. Tribhuvan
Kishor U. Tribhuvan
PTPunit Tyagi
Punit Tyagi
JTJyoti Taunk
Jyoti Taunk
MPMadan Pal
Madan Pal

31 July 2021 in Toxics
Verified
Journal Article
Open access
PDF file
RBRuchi Bansal
Ruchi Bansal
SPSwati Priya
Swati Priya
Dr. Harsh Kumar DikshitDr. Harsh Kumar Dikshit
Dr. Harsh Kumar Dikshit
SJSherry Rachel Jacob
Sherry Rachel Jacob
Mahesh RaoMahesh Rao
Mahesh Rao
Kadambot SiddiqueKadambot Siddique
Kadambot Siddique
Cadmium (Cd) is a hazardous heavy metal, toxic to our ecosystem even at low concentrations. Cd stress negatively affects plant growth and development by triggering oxidative stress. Limited information is available on the role of iron (Fe) in ameliorating Cd stress tolerance in legumes. This study assessed the effect of Cd stress in two lentil (Lens culinaris Medik.) varieties differing in seed Fe concentration (L4717 (Fe-biofortified) and JL3) under controlled conditions. Six biochemical traits, five growth parameters, and Cd uptake were recorded at the seedling stage (21 days after sowing) in the studied genotypes grown under controlled conditions at two levels (100 μM and 200 μM) of cadmium chloride (CdCl2). The studied traits revealed significant genotype, treatment, and genotype × treatment interactions. Cd-induced oxidative damage led to the accumulation of hydrogen peroxide (H2O2) and malondialdehyde in both genotypes. JL3 accumulated 77.1% more H2O2 and 75% more lipid peroxidation products than L4717 at the high Cd level. Antioxidant enzyme activities increased in response to Cd stress, with significant genotype, treatment, and genotype × treatment interactions (p < 0.01). L4717 had remarkably higher catalase (40.5%), peroxidase (43.9%), superoxide dismutase (31.7%), and glutathione reductase (47.3%) activities than JL3 under high Cd conditions. In addition, L4717 sustained better growth in terms of fresh weight and dry weight than JL3 under stress. JL3 exhibited high Cd uptake (14.87 mg g−1 fresh weight) compared to L4717 (7.32 mg g−1 fresh weight). The study concluded that the Fe-biofortified lentil genotype L4717 exhibited Cd tolerance by inciting an efficient antioxidative response to Cd toxicity. Further studies are required to elucidate the possibility of seed Fe content as a surrogacy trait for Cd tolerance.