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Ravishankar K.V.

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Designation: 
Principal Scientist
Division/Section: 
Division of Basic Sciences
Specialisation: 
Genomics and marker assisted breeding
Qualification: 
Ph. D in Crop Physiology
Research Accomplishments: 

(During the Period of 2019-2023)

Salient Achievements:

  1. Developed SSR markers using next-generation sequencing data  in Okra, Sapota,  Jackfruit, Custard apple and Jamun
  2. Interaction of beneficial micro-organisms and fungal/bacterial pathogens were studied using dual plate assay, Polyhouse conditions and field conditions, biochemical and gene expression analysis
  3.  Dual plate assay: The microbial inoculants JL-5, GJ-16B, LA, RSL showed complete inhibition of pathogen by overgrowth against Fusarium oxysporum (Guava wilt), Fusarium solani (Okra wilt) and Phytophthora capsici (Chilli foot rot and wilt). JL-4 and JL-5 (Trichoderma Sp.) was found effective in inhibiting the growth of Xanthomonas punica, causing bacterial blight in pomegranate.
  4. Growth promoting effects of bioagents: AMC and JL-5 enhanced the growth of tomato and chilli seedlings significantly.  The gene expression analysis of tomato treated with AMC and JL5 had shown that AMC had up-regulated the expression of growth related genes than compared to JL5. Upregulated genes in AMC and JL5 treatments have been involved in  pathways like MAPK signalling, ABC transporters and phenylpropanoid biosynthesis that are involved in promoting plant growth and priming plant defence responses.
  5. Early blight in tomato: Biochemical analysis of  intercation with Trichoderma spp. (JL-4 and JL-5) showed antifungal and growth promoting chemicals. JL5, GJ16B and UGF strain enhanced the activities of  POX, PPO and SOD enzymes imparting tolerance to tomato towards Alternaria solani infection. Under polyhouse conditions,  the bioagents GJ16B, JL5 and UGF reduced   PDI for tomato early blight. In gene expression studies, JL-5 and UGF treatments enhanced the expression of POX, PR2 and PR1 genes respectively in tomato seedlings inoculated with Alternaria solani.• Field trials on early blight in tomato: The bioagents GJ16B (Trichoderma sp.), JL5 (Trichoderma sp.), AMC (Arka Microbial Consortium) and UGF (Bacillus subtilis) were effective in reducing the PDI under field condition for tomato. GJ16B has performed well in controlling the disease in the field trials followed by JL5 and AMC.
  6. Effect of bioagents on fusarium wilt in okra: Bioagents like AMC, GJ16B and JL5 showed inhibition against Fusarium oxysporum vasinfectum infecting okra in polyhouse conditions. Enzyme activity of peroxidase and polyphenol oxidase, flavonoids and phenols were estimated in okra treated with bioagents, followed by F. oxysporum infection. Relative expression of the PR3 and PR10 genes in okra treated with JL5, GJ16B, AMC and the pathogen control plants showed that PR10 genes were activated during initial stages of fusarium wilt infection whereas PR3 genes play a major role during later stages of infection in okra.
  7. QTLseq analysis for fusarium wilt resistance in banana: QTLseq/Bulk segregant analysis was performed in banana cultivars ‘Calcutta 4’ and ‘Kadali’ for identification of QTLs conferring resistance to fusarium wilt disease in banana. Using QTLseq tool, three QTLs have been identified on the chromosomes 2, 9 and 10 of banana.
  8. Identification of QTLs linked to early blight disease of tomato, ToBaLCV in tomato and YVMV in Okra: QTL-seq analysis using  F2 population derived from resistant (8-3-3) and susceptible (PC) lines to  tomato early blight disease. A total of 298 segregating F2 lines developed from the cross PC×8-3-3 was used in this study for disease screening. Five QTL regions (eb2.1, eb2.2 eb2.3 and eb2.4) have been identified on the chromosome number 2 and another one QTL region (eb6.1) has been identified on chromosome 6. Similary five QTLs have been identified in tomato for ToBLCV.
  9. Identification of circular RNAs related to Tomato leaf curl Bangalore virus (ToLCBV) resistance in tomato: Transcriptome profiling of CircRNAs (Circular RNAs) from TV55 (resistant plant) in response for ToLCBVD infection revealed that about 53% of circRNAs were from exonic regions. A few target genes corresponding to differentially expressed CircRNAs includes cysteine-rich receptor-like protein kinase 25, Peroxidase, superoxide dismutase, Zinc finger transcription factor 33 and heat shock protein 90. ToLCBV infected TV55 (Resistant) and 15SBSB (Susceptible) tomato plants at different intervals (0, 3, 5, 9, 15 and 21 days post inoculation) were used for relative expression analysis. Relative expression of the parent genes Solyc02g080530.3 and Solyc02g088950.2 corresponding to CircRNAs were analysed in both resistant and susceptible genotypes at different time interval of ToLCBV infection correlated with the enzyme analysis for both superoxide dismutase (SOD) and peroxidase (POX).
  10. Gene expression analysis of tomato plants in response to flood stress in grafted tomato plants: Gene expression analysis of selected genes from the transcriptome data comparing tomato (Arka Rakshak) inter (with eggplant Arka Neelkanth) and intra grafted under flood stress with grafted control plants was done. The pattern of changes in both the flood stressed samples were similar when compared to the respective grafted controls with a few notable exceptions related to genes involved in ROS scavenging (Superoxide dismutase), cell elongation (Expansin-like protein) and photosynthesis. Similar study comparing tomato inter (with eggplant Arka Neelkanth) and intra grafted with non-grafted control plants was also done. The genes involved in ROS scavenging activity like Superoxide dismutase and Cytosolic ascorbate peroxidase have been significantly upregulated. The qPCR results correlated with the transcriptome data for the respective grafted and control samples.
  11. Comprehensive transcriptome analysis of okra and identification of genic SSR markers and long non-coding RNA: Comprehensive okra transcriptome data (root, stem, leaf, bud, flower, different parts of developing pods, drought stress, heat stress and salt stress plantlets) was used to identify 10492 SSRs (including 6516 mono repeats, 1285 di-repeats, 2112 tri repeats, 149 tetra repeats, 24 penta repeats, 9 hexa repeats) and 783 complex repeats. Tri repeats were found to be more abundant class of microsatellite than the di, tetra, penta and hexa repeats. The expected heterozygosity ranged from 0.125 to 0.971 with the mean value of 0.593; the values for observed heterozygosity ranged from 0.000 to 0.839 with a mean value of 0.203; the number of allele per locus ranged from 1 to 30 and the Polymorphic Information Content (PIC) ranged from 0.119 to 0.955 with the mean PIC value of 0.554. Dendrogram analysis showed that the genotypes used in the study were classified into three major clusters.
  12. Identification of long non-coding RNAs in Okra: Comprehensive okra transcriptome data was used to identify 57675 putative long non- coding RNAs (lncRNA) from pooled okra transcriptome data comprising 13 different parts. The length of lncRNA ranged from 211 to 4234bp. We have further classified these lncRNA based on its length as, small lncRNA (200- 950nts), medium lncRNA (950-3000nts) and large lncRNA (>3000nts) which accounted for 50761, 6860 and 54 lncRNAs respectively. Randomly 53 lncRNAs were selected from the identified lncRNAs of  and thier amplification was examined by polymerase chain reaction (PCR) amplification. A total of 1281 TFs were identified from the comprehensive okra transcriptome which were distributed in 51 transcriptional factor families.
  13. High-density linkage map construction in Banana: Genotyping by Sequencing (GBS) analysis was performed for 94 banana F1 progenies generated by crossing 'Bee Hee Kela’ and ‘Bhimathia’. The raw reads generated were filtered using trimmomatic tool. The filtered reads were aligned to the reference genome, DH Pahang V2.0 using burrow wheelers algorithm. A total of 4,32,338 SNPs were obtained after alignment with reference. Further, the SNPs were filtered based on the criteria; missing genotypes, minor allele frequency and Hardy Weinberg equilibrium after which a total of 30,421 high quality SNPs were obtained. The 30,421 SNPs were imported to JoinMap V5.0 software for linkage map construction. A high-density linkage map was constructed at LOD of 11 using Kosambi mapping function and the maps were drawn using ML (maximum likelihood) mapping. Out of 30,421 SNPs, 6894 SNPs formed 11 linkage groups spanning a total distance of 2268.55cM.
Varieties / Technologies Developed: 

 

Microsatellite markers developred for  okra, Jamun, Custard apple and Jackfruit

Publications: 

(Best 10/High Impact) 

  1. Das, A., Geetha, G. A., Ravishankar, K. V., Shivashankara, K. S., Roy, T. K., & Dinesh, M. R. (2019). Interrelations of growth regulators, carbohydrates and expression of flowering genes (FT, LFY, AP1) in leaf and shoot apex of regular and alternate bearing mango (Mangifera indica L.) cultivars during flowering. Scientia Horticulturae, 253, 263-269.
  2. Sampangi-Ramaiah, M. H., Ravishankar, K. V., & Rekha, A. (2019). Long non-coding RNAs in banana: prediction, mapping and their comparative studies using Musa balbisiana and Musa acuminata transcriptome. Trees, 33, 359-369.
  3. Kaushal, A., Sadashiva, A.T., Krishna Reddy, M., Srinivasa Rao, E., Singh, T.H., Sriram, S., Dhananjay, M.V., Venugopalan, R. and Ravishankar, K.V., 2020. Assessment of the effectiveness of Ty genes in tomato against Tomato leaf curl Bangalore virus. Plant Pathology, 69(9), pp.1777-1786.
  4. Sampangi-Ramaiah, M.H., Dey, P., Jambagi, S., Vasantha Kumari, M.M., Oelmüller, R., Nataraja, K.N., Venkataramana Ravishankar, K., Ravikanth, G. and Uma Shaanker, R., 2020. An endophyte from salt-adapted Pokkali rice confers salt-tolerance to a salt-sensitive rice variety and targets a unique pattern of genes in its new host. Scientific reports, 10(1), pp.1-14.
  5. Chandel, R., Sadashiva, A. T., Ravishankar, K. V., Das, A., Rout, B. M., & Singh, S. (2021). Genetic combining, heterosis analysis for horticultural traits in tomato (Solanum lycopersicum L.) using ToLCV-resistant lines and molecular validation of Ty genes. Plant Genetic Resources, 19(6), 512-521.
  6. Mathiazhagan, M., Chidambara, B., Hunashikatti, L. R., & Ravishankar, K. V. (2021). Genomic approaches for improvement of tropical fruits: fruit quality, shelf life and nutrient content. Genes, 12(12), 1881.
  7. Sathanandam, Pavithra N., Prakash Patil, Ajitha Rekha, Iyamperumal Muthuvel, Amrutlal R. Patel, Ramesh B. Boggala, Adiveppa M. Shirol, and Kundapura V. Ravishankar. "Development and characterization of microsatellite markers, genetic diversity and population structure analysis in Sapota (Manilkara zapota (L.) P. Royen)." Genetic Resources and Crop Evolution 69, no. 8 (2022): 2787-2801.
  8. Perveen, N., Dinesh, M. R., Sankaran, M., Ravishankar, K. V., Krishnajee, H. G., Hanur, V. S., ... & Irfan, M. (2023). Comparative transcriptome analysis provides novel insights into molecular response of salt-tolerant and sensitive polyembryonic mango genotypes to salinity stress at seedling stage. Frontiers in Plant Science, 14.
  9. Muthaiah, G., Elangovan, D., Mottaiyan, P., & Ravishankar, K. V. (2023). Comprehensive Transcriptome Analysis in Okra (Abelmoschus esculentus L. Moench): Analysis of LncRNA and Transcription Factors Involved in Abiotic Stress. Russian Journal of Plant Physiology, 70(3), 47.
  10. Chidambara, B., Muthaiah, G., Sadashiva, A. T., Reddy, M. K., & Ravishankar, K. V. (2023). Transcriptome analysis during ToLCBaV disease development in contrasting tomato genotypes. 3 Biotech, 13(7), 226.

Books Chapter 

  1. Sankaran M., Dinesh M.R., Ravishankar K.V. (2021) The Mango Genome. In: Classical Genetics and Breeding. Kole C. (eds) Compendium of Plant Genomes. Springer, Cham. ISBN- 978-3-030-47828-5
  2. Jayaswal, P. K., M. Srivastava, A. Bajpai, K. V. Ravishankar, and N. K. Singh. (2021). "Mango fruit transcriptome. Reference Module in Food Science. p592 - 601.
  3. Mathiazhagan, M., Padala, S., Doddahejjaji, S. G. C., Murugan, S., Makki, D. R., & Kundapura, R. V. (2022). Omics of mango: A tropical fruit tree. In: Omics in Horticultural Crops (pp. 427-448). Academic Press. ISBN-978-0-323-89905-5
  4. Laxman, R.H., Ravishankar, K.V., Prasanna, H.C., Ramesh, K.V., Rashmi, K., Kannan, S., Hara Gopal, K. and Darshan, S.S., (2022). Physiological, Molecular and Genetic Analysis of Abiotic Stress Tolerance in Tomato. In: Genomic Designing for Abiotic Stress Resistant Vegetable Crops (pp. 1-47). Springer, Cham. ISBN- 978-3-031-03963-8

 

Awards & Recognitions: 

 

  1. Member of Board of Studies UAS, GKVK for undergraduate studies in Biotechnology 2021-23
  2. Member of Research Advisory group  for the Institute of Wood Science and Technology, Bengaluru 2022
Email Address: 
ravishankar.kv@icar.gov.in
Telephone #: 
080-23086100 Extn 406