Browsing by Author "Fayas, T.P."

Now showing 1 - 14 of 14
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    Comparative study of three different methods of coconut plumule extraction for embryogenic callus induction
    (2012-11) Bhavyashree, U.; Lakshmi Jayaraj, K.; Fayas, T.P.; Sajini, K.K.; Rajesh, M.K.; Anitha Karun
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    A comparative study of three different methods of shoot meristem excision for induction of embryogenic calli in coconut
    (2016) Bhavyashree, U.; Lakshmi Jayaraj, K.; Fayas, T.P.; Muralikrishna, K.S.; Sajini, K.K.; Rajesh, M.K.; Anitha Karun
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    Computational prediction and characterization of miRNA from coconut leaf transcriptome
    (2015) Naganeeswaran, S.; Fayas, T.P.; Rachana, K.E.; Rajesh, M.K.
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    Development of a RAPD-derived SCAR marker associated with tall-type palm trait in coconut
    (2013) Rajesh, M.K.; Jerard, B.A.; Preethi, P.; Regi Jacob Thomas; Fayas, T.P.; Rachana, K.E.; Anitha Karun
    Coconut palms are classified into two major types, viz. talls and dwarfs, based on plant stature. The selection of coconut seedlings in the nursery, presently relying solely on morphological markers, often results in selection of out-crossed seedlings. Hence, identification of molecular markers for distinguishing tall/dwarf character at an early stage of growth assumes importance. In the present investigation, a RAPD marker for tall-type palm trait was identified using a pooled DNA approach. Screening of tall and dwarf palm bulked DNA with 200 decamer primers revealed a primer OPA09, producing a unique band of around 260 bp exclusively in tall accessions. The primer was used for screening and validation in individual tall and dwarf coconut accessions representing different geographic regions. The band was present in all the tall accessions, but absent in the dwarfs. Furthermore, sequence characterized amplified region (SCAR) primers were designed from the unique RAPD amplicon. The primers produced a specific 260-bp amplicon in tall accessions, but not in dwarf accessions. The SCAR marker was utilized in assessing the purity of hybrid seedlings of D×T (Dwarf×Tall) cross. The results pave the way for ensuring genuineness/quality of hybrid seedlings of coconut.
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    Effect of brassinosteroid, glutathione and adenine sulphate on callogenesis of coconut (Cocos nucifera L.) plumule
    (2012-11) Fayas, T.P.; Jeeha Muneem; Lakshmi Jayaraj, K.; Bhavyashree, U.; Sajini, K.K.; Rajesh, M.K.; Anitha Karun
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    Histological studies of cellular differentiation during somatic embryogenesis of coconut plumule-derived calli
    (2015-12) Lakshmi Jayaraj, K.; Bhavyashree, U.; Fayas, T.P.; Sajini, K.K.; Rajesh, M.K.; Anitha Karun
    Since coconut is one of the most recalcitrant species to generate in vitro, it is necessary to study in detail about the cellular changes that occur during somatic embryogenesis to enhance our knowledge about this phenomenon. In the present study, coconut plumular tissues, the shoot meristem including leaf primordia, were used as explants for in vitro regeneration studies. Histological studies were carried out in different stages of plumule culture. No noticeable growth was observed in 15 days old cultures. After 30 days, meristematic cells could be identified. Abundance of meristematic cells, foremost to the development of callus structures, was observed after 45 days. After 75 days, globular friable calli were formed and histological studies revealed the presence of meristematic centers which eventually formed somatic embryos. The histological study of matured somatic embryos formed after 120 days of callus initiation showed a clear meristematic zone of parenchyma cells, surrounded by vascular bundles. Histological studies, carried out for certain abnormalities like compact calli, abnormal somatic embryoids with rudimentary shoots and multiplied roots, revealed the presence of intact cotyledonary leaves which seemed to inhibit the apical meristem development of somatic embryoids. The presence of vascular bundles in the early stages of callus formation might lead to the direct formation of meristemoids. These results could aid future studies leading to enhanced control of the somatic embryogenic process and greater efficiency of somatic embryo and plantlet formation in coconut.
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    Histological studies of somatic embryogenesis of coconut plumule derived callus
    (2012-11) Lakshmi Jayaraj, K.; Bhavyashree, U.; Fayas, T.P.; Sajini, K.K.; Rajesh, M.K.; Anitha Karun
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    Leaf anatomy and molecular characterization of healthy and root (wilt) affected coconut palms
    (2012-11) Chinchu, K.; Fayas, T.P.; Radha, E.; Regi Jacob Thomas; Muralidharan, K.; Rejusha Ramakrishnan, P.; Anitha Karun
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    De novo assembly and characterization of global transcriptome of coconut palm (Cocos nucifera L.) embryogenic calli using Illumina paired-end sequencing
    (2016) Rajesh, M.K.; Fayas, T.P.; Naganeeswaran, S.; Rachana, K.E.; Bhavyashree, U.; Sajini, K.K.; Anitha Karun
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    De novo assembly and characterization of global transcriptome of coconut palm (Cocos nucifera L.) embryogenic calli using Illumina paired-end sequencing
    (2016) Rajesh, M.K.; Fayas, T.P.; Naganeeswaran, S.; Rachana, K.E.; Bhavyashree, U.; Sajini, K.K.; Anitha Karun
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    De novo assembly and characterization of global transcriptome of coconut palm (Cocos nucifera L.) embryogenic calli using Illumina paired-end sequencing
    (2016) Rajesh, M.K.; Fayas, T.P.; Naganeeswaran, S.; Rachana, K.E.; Bhavyashree, U.; Sajini, K.K.; Anitha Karun
    Production and supply of quality planting material is significant to coconut cultivation but is one of the major constraints in coconut productivity. Rapid multiplication of coconut through in vitro techniques, therefore, is of paramount importance. Although somatic embryogenesis in coconut is a promising technique that will allow for the mass production of high quality palms, coconut is highly recalcitrant to in vitro culture. In order to overcome the bottlenecks in coconut somatic embryogenesis and to develop a repeatable protocol, it is imperative to understand, identify, and characterize molecular events involved in coconut somatic embryogenesis pathway. Transcriptome analysis (RNA-Seq) of coconut embryogenic calli, derived from plumular explants of West Coast Tall cultivar, was undertaken on an Illumina HiSeq 2000 platform. After de novo transcriptome assembly and functional annotation, we have obtained 40,367 transcripts which showed significant BLASTx matches with similarity greater than 40 % and E value of ≤10−5. Fourteen genes known to be involved in somatic embryogenesis were identified. Quantitative real-time PCR (qRT-PCR) analyses of these 14 genes were carried in six developmental stages. The result showed that CLV was upregulated in the initial stage of callogenesis. Transcripts GLP, GST, PKL, WUS, and WRKY were expressed more in somatic embryo stage. The expression of SERK, MAPK, AP2, SAUR, ECP, AGP, LEA, and ANTwere higher in the embryogenic callus stage compared to initial culture and somatic embryo stages. This study provides the first insights into the gene expression patterns during somatic embryogenesis in coconut.
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    De novo assembly and characterization of global transcriptome of coconut palm (Cocos nucifera L.) embryogenic calli using Illumina paired-end sequencing
    (2016) Rajesh, M.K.; Fayas, T.P.; Naganeeswaran, S.; Rachana, K.E.; Bhavyashree, U.; Sajini, K.K.; Anitha Karun
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    Scope of novel and rare bulbiferous coconut palms (Cocos nucifera L.)
    (2013) Jerard, B.A.; Rajesh, M.K.; Elain, S.A.; Sajini, K.K.; Shafeeq Rahman; Fayas, T.P.; Anitha Karun
    A naturally occurring, rare bulbiferous coconut palm was identified at the Central Plantation Crops Research Institute, Regional Station, Vittal in Karnataka State, India, among West Coast Tall population. The palm produces only bulbil shoots in leaf axils in place of normal inflorescence. The identified palm happened to be twins in which one member was more vigorous than the other, but both of them produced only bulbil shoots instead of floral parts. Morphological and molecular studies on these palms revealed the main palm and their bulbil progenies are genetically uniform. The genetic uniformity of the twin mother palms and their bulbil progenies was confirmed through microsatellite analysis using 10 polymorphic SSR primer pairs specific to coconut and has been well demonstrated to differentiate coconut cultivars. The primary and secondary bulbil shoots were found to be capable of growing into independent plants making it possible to use them as propagules to develop a homogeneous clonal population hitherto unavailable in coconut. The bulbils showed axillary growth in 6–12th leaf axil which further again develop as secondary bulbils indicating the complete vegetative state of the palm. Comparison of shoot apices of a normal seedling with bulbil shoot revealed variation in cell growth pattern. Conservation of bulbiferous palms as a unique genetic resource needs to be taken up to utilize these rare sources for future breeding programmes, provided their seed-fertility can be restored.
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    Virtual screening and in vitro evaluation of potential growth regulators against somatic embryogenesis receptor- like kinase(SERK) in Cocos nucifera L.
    (2015) Rajesh, M.K.; Gangaraj, K.P.; Jamshinath, T.P.; Fayas, T.P.; Naganeeswaran, S.; Sajini, K.K.; Anitha Karun