Browsing by Author "Rajesh, M.K"

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    5-Azacytidine promotes the induction of embryogenic calli and somatic embryos from transverse thin cell layer (tTCL) cultures in coconut
    (2024) Keezhath Thazha Kuniyil Amritha; Muralikrishna, K.S.; Jasmin Habeeb; Chandran, K.P.; Paulraj, S.; Rajesh, M.K
    Coconut (Cocos nucifera L.) is highly recalcitrant to in vitro interventions. There is a need to overcome various bottlenecks to standardize a repeatable protocol for in vitro regeneration in coconut to meet the requirements of quality planting materials. Epigenetic processes, especially DNA methylation, are known to assay crucial roles in regulating genes controlling plant growth and development, especially somatic embryogenesis. In this study, we demonstrate that the supplementation of 5-azacytidine (5-azaC), a demethylating agent, in the coconut tissue culture media can enhance the formation of embryogenic calli, somatic embryos, and plantlet regeneration from transverse thin sections of mature zygotic embryos. Transverse thin cell layer (tTCL) sections of zygotic embryos were cultured onto Y3 medium supplemented with different concentrations of 5-azaC (0, 10, 15, and 20 μM), auxins (2,4-D, picloram and atrazine; 75 and 100 μM) and thidiazuron (TDZ;4.5 μM). Explants were exposed to constant 5-azaC and reduced auxin concentration in subsequent sub-culturing. Our results indicated supplementing 15 μM 5-azaC, in combination with picloram (75 μM) and TDZ (4.54 μM), improved the percentage of callusing (95.8%) and formation of embryogenic calli (87.5%), and formation of somatic embryos (4.7) and plantlets (4.0) per explant in comparison with control having 80.8%, 75.0%, 1.6 and 0.67, respectively from tTCL sections of mature zygotic embryos. The results will form the basis for designing more efficient coconut tissue culture protocols.
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    A new pod bioassay method to determine the toxicity of insecticides against Tea mosquito bug, Helopeltis theivora
    (2024) T. N. Madhu; Saneera, E.K; R. Thava Prakasha Pandian; Sujithra, M; Bhavishya; Nagaraja, N.R.; Elain Apshara, S.; Josephrajkumar, A.; Rajesh, M.K
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    Arecanut
    (2017) Nagaraja, N.R.; Ananda, K.S.; Rajesh, M.K
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    Arecanut
    (2017) Anitha Karun; Krishna Prakash; Rajesh, M.K; Chowdappa, P
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    Artificial intelligence in plantation crops
    (2019) Chowdappa, P; Ravi Bhat; Mathew, A.C; Rajesh, M.K
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    Assimilating socio-economic perspective in designing crop sector technology interventions: A farmer participatory study on coconut sector in Kerala
    (2019-12) Thamban, C.; Lijo Thomas; Chandran, K.P.; Jayasekhar, S.; Rajesh, M.K; Jesmi Vijayan; Srinivasan, V.; Nair, K.M.; Anil Kumar, K. S.
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    Cocoa
    (2017) Anitha Karun; Aparna, V.; Muralikrishna, K.S; Rajesh, M.K
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    Cocoa
    (2017) Anitha Karun; Aparna, V.; Rajesh, M.K; Chowdappa, P
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    Coconut
    (2017) Anitha Karun; Sajini, K.K.; Aparna, V.; Rajesh, M.K
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    Coconut
    (2017) Anitha Karun; Muralikrishna, K.S; Rajesh, M.K; Chowdappa, P
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    Coconut
    (2017) Neema, M.; Rajesh, M.K; Ramesh, S.V.; Chowdappa, P
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    Coconut Biotechnology
    (2018) Rajesh, M.K; Anitha Karun; Parthasarathy, V.A.; p
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    Coconut Tissue Culture: The Indian Initiatives, Experiences and Achievements
    (2017) Anitha Karun; Rajesh, M.K; Sajini, K.K.; Muralikrishna, K.S; Neema, M.; Shareefa, M.; Regi Jacob Thomas
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    COCONUT(COCOS NUCIFERA L.)POLLEN CRYOPRESERVATION
    (2014) Anitha Karun; Sajini, K.K.; Niral, V.; Amarnath, C.H.; Remya, P.; Rajesh, M.K; Samsudeen, K; Jerard, A.; Florent Engelmann
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    Differentiation of Phytophthora species associated with plantation crops using PCR and high-resolution melting curve analysis
    (2018) Prathibha, V.H.; Vinayaka Hegde; Sharadraj, K.M; Rajesh, M.K; Rachana, K.E.; Chowdappa, P
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    Effect of light-emitting diodes on the proliferation of immature endosperm derived calli of coconut (Cocos nucifera L.)
    (2024) Geethu Venugopal; K.S. Muralikrishna; Sugatha Padmanabhan; Rajesh, M.K
    Coconut endosperm has a unique fatty acid profile with a pre-dominance of saturated fatty acids like lauric acid and myristic acid. Manipulation of fatty acid biosynthesis pathways can be possible with in vitro multiplication of endosperm tissue in this important oil yielding perennial palm tree. In this study, influence of Light Emitting Diodes (LEDs)(blue, yellow and purple colored) was investigated on in vitro initiation and proliferation of coconut endosperm calli. Biomass accumulation, total soluble sugars, reducing sugars, free amino acids, total polyphenols and fatty acid profile were estimated from endosperm calli of Gangabondam Green Dwarf (GBGD) cultivar grown under different colored LEDs. Calli grown under dark conditions served as control. Results indicated that initiation of calli was faster under dark conditions, whereas the multiplication and proliferation was significantly high under purple LED. Production of total soluble sugars, reducing sugars, total polyphenols and fat contents were enhanced in cultures under LEDs in comparison to control. Fatty acid profiles, generated through gas chromatography (GC), indicated that medium chain saturated fatty acid content was more, while long chain saturated and unsaturated fatty acid content was less in cultures grown under LEDs compared to cultures under control conditions. It is evident from the results that coconut endosperm calli can be initially initiated under dark conditions and it has the potential to proliferate under LED conditions with significant impact on fatty acid synthesis.
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    Identification and utilization of informative EST-SSR markers for genetic purity testing of coconut hybrids
    (2016-08) Preethi, .P; Rajesh, M.K; Rahul, C.U; Jerard, B.A.; Samsudeen, K; Regi Jacob Thomas; Anitha Karun
    Coconut palms are categorized into two forms, viz., ‘talls’ and ‘dwarfs’ which are being utilized to produce hybrids through the process of inter-varietal or intra-varietal crosses. Hybrid coconut seedlings are generally identified and selected based on morphological traits by plant breeders, which is quite difficult and requires expertise. Even minor errors in identification may adversely affect breeding programs in coconut, which is spread over many decades. In this study, we have utilized thirty EST-SSR markers, derived from existing coconut leaf transcriptome data, for screening polymorphism between eighteen coconut parental lines. The polymorphic primers capable of differentiating the parental palms were then utilized successfully for assessment of purity of hybrids derived from these parents. Thus, the current study demonstrates the utility of EST-SSR markers in determining the genetic purity of hybrids in coconut.
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    In vitro regeneration of coconut plantlets from immature inflorescence
    (2019) Shareefa, M.; Regi Jacob Thomas; Sreelekshmi, J.S; Rajesh, M.K; Anitha Karun
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    Insect Neuropeptides and Application in Pest Management
    (2018) Joseph Rajkumar, A.; Rajesh, M.K; Chowdappa, P