Relative abundance and diversity of insect foragers associated with inflorescence in dwarf varieties of coconut (Cocos nucifera L.) Regi J. Thomas, A. Josephrajkumar, Bharath Mohan, Sandip Shil, M. Shareefa Current Science, 2025 Ecosystem services offered by insect foragers in the coconut system are exceptional in utilizing pollen and nectar resources and, thereafter, rewarding effective pollination in coconut palms.The pollinator community recorded from dwarf varieties of coconut comprised 35 insect species, out of which 30 could be identified, belonging to 6 orders and 17 families.Insect fauna belonging to families Formicidae (ants), Apidae (bees) under Hymenoptera and Curculionidae (weevils) under Coleoptera were recorded in abundance from the coconut inflorescence.However, a considerable quantity of pollen grains clings onto the body parts of bees and assumes likely pollination services in coconut.Ants, though noticed in large numbers, may not be involved in pollination, probably because of their apterous nature and smooth body surfaces warranting in-depth scrutiny.Abundant floral visitors were registered during January-July compared to August-December.Higher nut yield in coconut recorded during January-May could be positively linked to enhanced foraging activities by insects, a classical instance of ecosystem services delivering economic benefits to farmers.The maximum insect activity was during the forenoon session, coinciding with anthesis time of coconut.Modulation among various diversity indices (Menhinick index, Shannon's index) were recorded for species richness and temporal abundance for insect visitation in coconut.Conservation of these pollinators in the perennial coconut system is crucial for sustaining production and safeguarding the ecosystem.As coconut produces inflorescence around the year and ensures continuous pollen availability, coconut orchards can also be used for division of honey bee colonies during the brood rearing season.
Chromosome scale genome assembly and annotation of coconut cultivar Chowghat Green Dwarf M. K. Rajesh, Roli Budhwar, Rohit Shukla, Praveen Kumar Oraon, Shailendra Goel, Bobby Paul, Regi Jacob Thomas, Akshay Dinesh, S. Jayasekhar, K. P. Chandran, K. S. Muralikrishna, B. J. Nirmal Kumar, Alpana Das Scientific Reports, 2024 The high-quality genome of coconut (Cocos nucifera L.) is a crucial resource for enhancing agronomic traits and studying genome evolution within the Arecaceae family. We sequenced the Chowghat Green Dwarf cultivar, which is resistant to the root (wilt) disease, utilizing Illumina, PacBio, ONT, and Hi-C technologies to produce a chromosome-level genome of ~ 2.68 Gb with a scaffold N50 of 174 Mb; approximately 97% of the genome could be anchored to 16 pseudo-molecules (2.62 Gb). In total, 34,483 protein-coding genes were annotated; the BUSCO completeness score was 96.80%, while the k-mer completeness was ~ 87%. The assembled genome includes 2.19 Gb (81.64%) of repetitive sequences, with long terminal repeats (LTRs) constituting the most abundant class at 53.76%. Additionally, our analysis confirms two whole-genome duplication (WGD) events in the C. nucifera lineage. A genome-wide analysis of LTR insertion time revealed ancient divergence and proliferation of copia and gypsy elements. In addition, 1368 RGAs were discovered in the CGD genome. We also developed a web server 'Kalpa Genome Resource' ( http://210.89.54.198:3000/ ), to manage and store a comprehensive array of genomic data, including genome sequences, genetic markers, structural and functional annotations like metabolic pathways, and transcriptomic profiles. The web server has an embedded genome browser to analyze and visualize the genome, its genomics elements, and transcriptome data. The in-built BLAST server allows sequence homology searches against genome, annotated transcriptome & proteome sequences. The genomic dataset and the database will support comparative genome analysis and can expedite genome-driven breeding and enhancement efforts for tapping genetic gains in coconut.
Cytological confirmation of ploidy level in a rare twin haploid of coconut (Cocos nucifera L.) Regi J. Thomas, Maya Lekshmi, M. Shareefa, J. S. Sreelekshmi, Abe Jacob Indian Journal of Genetics and Plant Breeding, 2024 A rare occurrence of a haploid coconut from a twin seedling was observed in a natural population. The haploid nature of the seedling was confirmed using cytology and ploidy analysis. Amplification of tall-specific SCAR marker in the diploid seedling suggested a possible natural cross by pollen from a WCT palm. The haploids identified in the nursery may be a possible route for generating a pure line of coconut that can be used in future breeding programs.
Analysis of Farmer Producer Organisations in the coconut sector: current scenario, limitations, and policy outlook S. Jayasekhar, C. Thamban, Kavitha Chandran, Lijo Thomas, Regi J. Thomas Journal of Plantation Crops, 2024 Farmer producer organisation is a crucial institutional innovation that aids small holders in overcoming the issues of diseconomies of scale. Nonetheless, prior experience in the coconut sector reveals that the success rates of such organisations are not as high as projected. This article begins by exploring the relevance of FPOs in the current agrarian context and gives a brief account of the evolution of such organisations in the coconut sector. The study also highlights the points for intervention and provides a critical analysis of the significance and justification for FPOs in the sector. It also includes the challenges and actionable strategies in a ready reckoner mode. The primary motivation for the formation of producer organisations in the coconut sector is to organise unorganized coconut farmers through collectives in order to promote their socioeconomic growth. The success of an FPO is heavily dependent on having a solid business plan, and scope for scalability. Inadequate working capital, including grants and credit, is a major limitation for the majority of FPOs. In this setting, it is critical to obtain bank loans at low interest rates. The development of a well recognised and valued brand is critical for the FPO's viability. Lack of professional leadership has a negative impact on FPOs in the coconut sector, and many have gone out of business as a result. To assist them, target based capacity-building programme to inculcate leadership attributes among FPO representatives should be conducted on a regular basis. Only a few FPOs in the coconut industry have looked into the prospect of gaining premium pricing through certification techniques and product traceability. This is due to a lack of both capacity and awareness. This problem must be addressed with ultimate priority. The FPOs must be trained to be self-sufficient and weaned off external assistance in a short period of time after the initiation. Therefore, FPOs should focus on increasing productivity per unit of land and shifting their current production focus to market-oriented output.
Occurrence of in vitro flowering in coconut (Cocos nucifera L.) M. Shareefa, Robert J. Thomas, J S Sreelekshmi, K. Anitha Journal of Horticultural Sciences, 2022 Immature inflorescence with outer spathe length of 5.5 cm size collected from West Coast Tall cultivar of coconut was used as the explant and rachillae bits were inoculated in Y3 media supplemented with 2, 4-D (1 mg L-1). The cultures were incubated in dark for eight months and sub-cultured into the same media at monthly interval. The white shoot like outgrowths formed were sub cultured to ½ MS media fortified with 1 mg L-1 each of NAA and BAP and subsequently transferred to light condition. After three months, the emerging shoot likestructure was transferred to Y3 media fortified with NAA and BAP. Upon developing 3 - 4 leaves, the cultures were transferred to rooting media and root initiation was observed after two months. The transition of vegetative shoot to reproductive state was accompanied by some morphological changes including rapid emergence of long and thin leaves followed by emergence of pearly white inflorescence. Unlike normal inflorescence, the inflorescence emerged was terminal and was devoid of spathe. Prolonged subculture in the same media might have resulted in pH variation and subsequent reduction in organic and inorganicconstituents of the media. The chemical stress experienced by the plantlet might have induced in vitro flowering.
Evaluation of dwarf varieties of coconut for wilt resistance, nut yield and quality of tender coconut water Regi J. Thomas, M. Shareefa, C. K. Nampoothiri, Jeena Mathew Indian Journal of Horticulture, 2022 The present study was undertaken to evaluate the suitability of dwarf varieties of coconut for tender nut purpose in the root (wilt) disease prevalent tracts. Studies revealed that quantity and quality of tender coconut water differed significantly depending on the variety. Among the varieties, volume of tender nut water was highest for King Coconut, but the quality of tender nut water was rated only as average. Quality of tender nut water in terms of total soluble solids (TSS) and organoleptic evaluation score was highest for Gangabondam Green Dwarf. There was no significant difference in pH of the tender nut water of different varieties and the values ranged from 5.06 to 5.34. The mineral composition of tender nut water was also estimated and highest potassium content was recorded in Niu Leka Dwarf (2285 ppm) followed by Andaman Green Dwarf (2182.5 ppm). However, highest sodium content was recorded in Andaman Green Dwarf (34.6 ppm) followed by King Coconut (19.63 ppm). Characters like volume of tender nut water, TSS, organoleptic score, potassium content, nut yield and reaction to root (wilt) disease were considered for selecting the most suitable tender nut varieties. Gudanjali Green Dwarf, Andaman Green Dwarf and Kalpasree were found to be promising for the root (wilt) disease prevalent tract owing to its tender nut qualities, nut yield and resistance to root (wilt) disease.
Biochemical characterization of pink husked coconut types Regi J. Thomas, M. Shareefa, H. Harsha, Anitha Karun Journal of Plantation Crops, 2021 Coconuts with various traits are available in different coconut growing countries. The pink husk is one such trait that has already been reported in coconut. There is a demand for tender nut water from pink husked types of coconut to treat hepatitis by traditional medicinal practitioners. Present studies were carried out to characterize pink husked types identified in Guam Tall variety of coconut. There were no morphological differences with respect to the nut characters between pink and non-pink husked types. Biochemical characterization of pink husked types revealed significantly higher total phenol content in the tender nut water of pink husked types than normal husked types. A significantly higher protein content of 86 mg 100 mL-1 was noted in pink husked type, compared to normal husked type with 58.7 mg 100 mL-1. Higher free radical scavenging activity based on DPPH assay with pink husked type was recorded with an IC50 value of 266.7 compared to normal type with an IC50 value of 358. Similarly, phosphomolybdate assay also revealed higher scavenging activity of pink husked type based on the IC50 value of 415.2 compared to 637.9 observed in normal husked type. Anthocyanin content of 25.98 mg 100g-1 fresh weight was noted in the exocarp of pink husked types, and it was negligible in normal husked type. These results justify the use of pink husked coconuts in various traditional medicines. There is tremendous potential for exploiting pink husked types of coconut in the pharmaceutical industry.
Screening and characterization of nutrient solubilizing phytobeneficial rhizobacteria from healthy coconut palms in root (wilt) diseased tract of Kerala, India S. Indhuja, , M. Babu, A. Gupta, M. Gopal, J. Mathew, R.J. Thomas, A.A. Haris, V. Krishnakumar, , , , , , , and Journal of Environmental Biology, 2021 Aim: Isolation, screening and characterization of beneficial rhizosphere bacteria associated with healthy (field-resistant) coconut palms in root (wilt) disease endemic hotspot areas of Kerala. Methodology: One hundred and ten rhizobacterial isolates associated with healthy coconut palms of root (wilt) diseased tract of Kerala were isolated and screened in-vitro for IAA production and solubilization of fixed forms of mineral nutrients. Seven isolates showing multiple phytobeneficial properties were characterized and the selected isolate was tested for its biopriming effect on maize. Results: Of the total isolates screened, 54 isolates produced IAA. Among the nutrient solubilizers, silicate solubilizers (57%) and phosphate solubilizers (48%) dominated. Of the seven isolates with multiple phytobeneficial properties, five rhizobacterial isolates belonged to Enterobacteriaceae family including three Enterobacter spp. The isolate T4HFB9 belonged to Acinetobacter sp. The green fluorescent Pseudomonas isolate K3HPSB2, showed 99% sequence similarity with Pseudomonas migulae. Seed biopriming of maize with Pseudomonas sp. strain K3HPSB2 recorded significant increase in germination percentage and seedling vigour index over untreated control. Interpretation: Disease-resistant coconut palms in RWD endemic tracts host a good proportion of phytobeneficial rhizosphere bacteria,with demonstrable multiple plant growth promoting traits. Multi-nutrient solubilizing Pseudomonas sp. with bioinoculant prospects has been selected for further studies on bio-priming for palm health management in RWD endemic tracts.
A durable pollination raincoat for hybridization during monsoon in coconut K. Devakumar, Regi Jacob Thomas, Anitha Karun Journal of Plantation Crops, 2020 Large-scale production of hybrid seed nuts of coconut is necessary to match the high demand for hybrid seedlings. But in major coconut producing states such as Kerala, Karnataka and Goa hybridisation is carried suspended during monsoon season and out effectively only during dry season for a period of six months from November to May. Some of the reasons attributed to the stoppage of pollination work during monsoon are the slippage of the trunk while climbing, problems in male flower collection and wetting of the pollination bags during heavy rains. Technological developments in coconut sector viz., the invention of coconut climbing devices and cryopreservation techniques have contributed to safe climbing and pollen storage for utilisation during off-seasons, respectively. However, the wetting of the pollination bag used for hybridization remains a problem. We report the development and successful initial testing of a durable raincoat for the pollination bag so that coconut pollination can be carried out throughout the year in heavy monsoon areas. This reusable raincoat is integrated with the ground pollination unit and can be fitted easily on the pollination bag, and it ensures complete dryness of the pollination bag. Only one climbing per tree is required for emasculation, bagging and raincoat fitting on a single inflorescence. The raincoat has provisions for suspending a pollen delivery tube and pollen dusting and bag removal can be done from the ground. The durable raincoat cover for the pollination bags has resulted in a fruit setting of 22.5-41.3 per cent.
Diversity studies using molecular markers Chandrika Perera, H. D. Dharshani Bandupriya, Regi J. Thomas, Roland Bourdeix Coconut Biotechnology Towards the Sustainability of the Tree of Life, 2020 The introduction of molecular markers in the latter part of the twentieth century denoted a major advancement in the research on plant genetics. Molecular markers have become highly advantageous to help overcome certain inherent difficulties associated with the genetic improvement of perennial crops such as coconut. Starting from the middle of the 1990s, considerable progress has been achieved in the genetic diversity analysis of coconut. The early attempts of molecular research on coconut used the common molecular marker systems of the time, such as randomly amplified polymorphic DNA and amplified fragment length polymorphism. Later, the generation of coconut-specific DNA markers and the adoption of high-throughput systems have paved the way for an acceleration, with greater accuracy, in using molecular markers for diversity studies in coconut. Molecular markers have also been used in the development of linkage maps and the identification of quantitative trait loci (QTL) in coconut. The research using molecular markers has been used, and will be further useful, in formulating and refining the further collection and conservation of coconut germplasm, the management of genebanks, identification of duplicates, and determining the strategies for rejuvenation of the existing field genebanks. The data can further be used in the parental selection in the coconut breeding programmes aimed at combining the desirable characters from diverse parents into novel cultivars. The availability of high-throughput marker systems will increase the accuracy and precision of genetic and QTL mapping via linkage analysis. Further, association studies which facilitate the use of existing populations in QTL mapping will be an important tool in moving towards marker-assisted selection of coconuts for desirable traits to ensure sustainability of the coconut industry.
Coconut breeding in India Raman V. Nair, B. A. Jerard, Regi J. Thomas Advances in Plant Breeding Strategies Agronomic Abiotic and Biotic Stress Traits, 2016
Genetic purity assessment of D x T hybrids in coconut with SSR markers Indian Journal of Genetics and Plant Breeding, 2012
Studies on fruit set in coconut upon artificial pollination in various cross combinations Indian Journal of Horticulture, 2012
Analysis of population structure and genetic relatedness among root (wilt) disease-resistant and susceptible west coast tall coconut palms (Cocos nucifera) using microsatellite markers Indian Journal of Agricultural Sciences, 2011
Improving food and nutritional security of small and marginal coconut growers through diversification of crops and enterprises Journal of Agriculture and Rural Development in the Tropics and Subtropics, 2010
