Eastern Ghats Research Articles

Gravity-magnetic appraisal of the southern part of the Cauvery Basin, Eastern Continental Margin of India (ECMI): evidence of a volcanic rifted margin

The Cauvery sedimentary basin of India, a part of the Eastern Continental Margin of India (ECMI), has evolved as a consequence of its breakup from East Antarctica in the early Cretaceous. This study covers approximately 10,000 km2 in the southern part of the Cauvery basin. A total of 5,161 gravity-magnetic observations were made in an area bounded by 78°–79°E longitude and 9°–10°N latitude. The gravity anomaly map shows a dominant NE-SW trend with a total relief of 83 mGal from −77 mGal to 6 mGal. The map reveals very prominent NE-SW trending linear gravity high bands and two circular/elliptical gravity lows around Madurai and Ramanathapuram, respectively. The residual gravity map reveals NE-SW trending alternative bands of gravity highs and lows, revealing a ridge-depression structure. The gravity modeling shows the presence of underplated material, which may be related to magmatic activity during the Cretaceous. The magnetic map reveals two prominent E-W trending linear structures, which probably represent the disposition of a shear zone under the Cauvery Basin. Based on the filtered magnetic and gravity map, we have prepared an interpreted basement geology map. The magnetic map and residual gravity map suggest that the basement rock of the basin is crystalline (granite/gneiss) and may not comprise a high-grade metamorphic rock Eastern Ghat Orogeny.

Identification and Molecular Characterization of Rhizopus delemar from Eastern Ghats of State of India and its Biotechnological Applications

The humid climatic condition of the Koraput district of the eastern ghat of Odisha, India favors the growth of a diverse range of microbial and fungal strains, which not only lay scathing consequences on the environment but also prove to be beneficial in many industrial and biotechnological sectors. Hence, proper exploration of their roles and impacts is the necessity for an hour. With this goal, the present study reports on the identification and molecular characterization of the fungal strain collected from Koraput district of the eastern ghat of Odisha. The fungal strain was cultured, isolated, and identified using Internal transcribed spacer (ITS) 18S rRNA-specific primers. The estimation of fungal biomass was carried out by taking the dry weight of fungal mycelia after 48, 72, 96, and 120 hours of inoculation, which showed an increase in biomass (in w/w) exponentially. The fungal isolate (CAR02) was identified as Rhizopus delemar with GenBank accession number OQ683833. The SDS PAGE protein analysis showed more intensified and concentrated multiple fungal protein bands ranging from 13 to 97 kDa. ELISA (Enzyme- Linked Immunosorbent Assay) was used to estimate the antigenicity of the isolated R. delemar proteins from soil samples of Koraput. The proteins of Pythium species with an absorbance value of 1.5 shared 50-60% of similar antigenic sequences with the R. delemar proteins. Hence, the findings of our investigation suggests that the obtained antigenic sequences could further be used to isolate its epitopic specific regions that are responsible for the rot infections, against which antibodies could be developed. Further study is required to explore the rot causing fungal diversity in the soil of eastern ghats which will be helpful in designing novel disease diagnostic strategies in agriculture sectors. Furthermore, this identified fungus can also be used to synthesize various enzymes that will aid in the production of commercially significant by-products.

Genome sequencing and characterization of microsatellite markers of Pterocarpus santalinus L.f.: an economically important endangered tree of Eastern Ghats, India

Genome sequencing and characterization of microsatellite markers of Pterocarpus santalinus L.f.: an economically important endangered tree of Eastern Ghats, India

Competitive ability of legume based intercrop for rabi maize (Zea mays L.) in north eastern ghats of Odisha

Competitive ability of legume based intercrop for rabi maize (Zea mays L.) in north eastern ghats of Odisha

Residual Effect of Integrated Nutrient Management in Kharif Maize (Zea mays L.) on Growth and Yield of Toria (Brassica campestris L. var. Toria) during Rabi Season in Odisha, India

A field experiment was carried out at Regional Research and Technology Transfer Station (OUAT), Semiliguda of Koraput district under Eastern Ghat High Land zone of Odisha in acidic soil during two consecutive rabi seasons of 2016-17 and 2017-18 to study the residual effect of integrated nutrient management in maize on succeeding toria crop. The experiment was laid out in randomized block design with three replications consisting of twelve treatments. The present investigation revealed that application of soil test based fertilizer with green leaf manure (cowpea), FYM @ 5 t ha-1 and biofertilizer (Azotobacter + Azospirillum + PSB @ 4 kg ha-1 each) to maize crop registered maximum residual effect thereby resulted significantly highest seed yield (6.3 q ha-1) and stover yield (11.1 q ha-1) of toria with a net monetary return of Rs. 7025 ha-1 and benefit cost ratio of 1.38.

Nutritional and nutraceutical variability in neglected niger (Guizotia abyssinica (L.f.) Cass.) accessions from Eastern Ghats of India

The exploitation of neglected niger accessions plays a crucial role in future breeding programs aimed to enhance the quality. Present study evaluated the genetic variation in nutritional and nutraceutical compositions of 30 indigenous niger accessions originating from Eastern Ghats of India, and compare them with three improved varieties of the locality. The proximate compositions (g/100 ​g) showed significant variations, with moisture ranging from 1.36 ​g to 4.95 ​g, ash from 1.06 ​g to 5.45 ​g, fat from 28.53 ​g to 44.11 ​g, protein from 8.84 ​g to 18.18 ​g, carbohydrate from 11.21 ​g to 35.09 ​g, fiber from 16.32 ​g to 26.62 ​g, and energy from 407.32 ​Kcal to 526.84 ​kcal. Niger seeds are rich in phenol 41.10–82.20 ​mg/g, flavonoid 5.32–15.98 ​μg/g, antioxidant 13.59–31.08% across the accessions. Principal component analysis revealed that the first two axis explained 41.8% of the total variation, indicating significant differences among genotypes. The heritability and genetic advance in percent of mean (GAM) ranged from 61.11% to 99.91% and 12.5%–89.1% among the traits across the populations. High heritability and GAM recorded in vitamin C, ash content, antioxidant capacity, flavonoid and phenol suggests that these traits may be important for niger breeding program. Altogether, some indigenous niger accessions such as Mangardora, Ganjeipadar and Kolabnagar had exceptionally rich in fat, protein and energy contents and are nutritionally superior compared to improved variety of the locality. Further, exceptional rich in flavonoid, antioxidant capacity and vitamin C was recorded in Manahar, Badapada and Mahadeiput. These nutrition rich accessions have ample opportunities for future breeding programs aimed to enhance the quality and hold great potential in food industry for making high value functional food.

Molecular Evidence of Rickettsia conorii subsp. raoultii and Rickettsia felis in Haemaphysalis intermedia Ticks in Sirumalai, Eastern Ghats, Tamil Nadu, South India.

Rickettsia is an important pathogenic entity among tick-borne diseases (TBD), which are considered serious emerging public health problems globally. In India, though the widespread distribution of ticks and TBD has been documented, its real burden remains underreported. In a preliminary attempt, rickettsial surveillance was carried out in ticks collected from Sirumalai, Eastern Ghats in Tamil Nadu, India by using pathogen genome-based phylogenetic inferences generated through multi-locus sequence typing (MLST), targeting the genes 16s rRNA, OmpA, OmpB, and gltA by nested PCR. The laboratory evidence confirms the circulation of Rickettsia in Haemaphysalis intermedia species collected from this area. Analysis of the four gene sequences detected demonstrates their closest identity to the spotted fever group (SFG) available in the GenBank database. Further, multiple sequence alignment with other sequences derived from the GenBank database showed close relatedness to Rickettsia conorii subsp. raoultii (16s rDNA-99.32%, OmpA-93.38%, OmpB-97.39%, and gltA-98.57%) and Rickettsia felis (16s rDNA 99.54%, OmpA-100%, OmpB-100% and gltA-99.41%). With this genomic evidence, the circulation of rickettsial pathogens in the pools of H. intermedia ticks infesting livestock in the Sirumalai foothill area has been demonstrated and to complement the microscopic identification of the tick species, DNA barcodes were generated for H. intermedia using the mitochondrial cytochrome c oxidase subunit I gene (COI). Nevertheless, R. raoultii and R. felis were found to be the aetiological agents of tick-borne lymphadenopathy and flea-borne spotted fever in human cases, respectively, further study on the determination of their diversity, distribution, clinical relevance, and potential risk to the local community in these areas is highly warranted.

Assessment of Plant Diversity in Bodakondamma Sacred Grove, Eastern Ghats of Visakhapatnam District, Andhra Pradesh, India

The present investigation reflects the findings of Assessment of plant Diversity which have been undertaken in the sacred grove of Bodakondamma, Eastern Ghats of Visakhapatnam district, Andhra Pradesh, India. The forest types of Sacred Grove are mainly dry deciduous forest. Plant diversity assessment was conducted during 2021 - 2022. The survey documentation of the plant species in the Sacred Grove area were recorded a total of 67 species are trees and 45 species are shrubs and 73 species are herbs and 45 species are climbers. This study provides preliminary information on the sacred groves of Bodakondamma. Appropriate conservation and management can considerably improve the plant diversity value of Sacred Grove of Eastern Ghats, Visakhapatnam District.

Plant Biodiversity Assesment in Galikonda Forest, Eastern Ghats of Alluri Sitaramaraju District, Andhra Pradesh, India

A landscape level plant diversity and population inventory was made in High altitude forest of eastern Ghats, Visakhapatnam District, Andhra Pradesh, India comprising mostly dry deciduous and moist deciduous forests. In all the three study sites, two belt transects of 5 × 1000 m size (totaling 1 ha) were laid in each site during 2022–2023 and all trees with ≥15 cm girth at breast height (gbh) were enumerated. Within each transect of 1000 x 5 m, quantitative data in respect of herb species was collected from two numbers of small sample plots each measuring 1m x 1 m. A total of 246 species was recorded on enumeration, of which 54 Trees, 50 Shrubs and 90 Herbs were noted.

The draft genome reveals early duplication event in Pterocarpus santalinus: an endemic timber species.

A 541Mb draft genome of Pterocarpus santalinus is presented and evidence of whole-genome duplication in the Eocene period with expansion of drought responsive gene families is documented. Pterocarpus santalinus Linn. f., popularly known as Red Sanders, is a deciduous tree, endemic to southern parts of Eastern Ghats in India. The heartwood is highly valued in the international market due to its deep red colour, fragrant heartwood and wavy grained texture. In the present study, a high-quality draft genome of P. santalinus was assembled using short and long reads generated from Illumina and Oxford Nanopore Sequencing platforms, respectively. The haploid genome size was estimated at 541Mb and the hybrid assembly showed 99.60% genome completeness. A total of 51,713 consensus gene set were predicted with 31,437 annotated genes. The age of the whole-genome duplication event in the species was dated at 30-39mya with 95% confidence suggesting early genome duplication event during the Eocene period. Concurrently, phylogenomic assessment of seven Papilionoideae members including P. santalinus grouped the species based on the tribal classification and established divergence of the tribe Dalbergieae from tribe Trifolieae at ~ 54.20mya. A significant expansion of water deprivation/drought responsive gene families documented in the study probably explains the occurrence of the species in dry rocky patches. Additionally, re-sequencing of six diverse genotypes predicted one variant every 27 bases. This report presents the first draft genome in the genus Pterocarpus and the unprecedented genomic information generated is expected to accelerate population divergence studies in the species in relation to its endemic nature, support trait-based breeding programme and aid in development of diagnostic tools for timber forensics.

Avian species diversity in three major forest types in part of northern Eastern Ghats, Odisha, India

Avian species diversity in three major forest types in part of northern Eastern Ghats, Odisha, India

Diversity and Distribution Pattern of Herpetofauna in Tropical Forest Microhabitats of Eastern Ghats, Odisha

Diversity and Distribution Pattern of Herpetofauna in Tropical Forest Microhabitats of Eastern Ghats, Odisha

A Study on Effectiveness of Tabos and Cultural Practices on Bio-diversity Conservation in Eastern Ghats of Tamil Nadu, India

Taboos and cultural practices are regulates people the way interact with the world around them by prohibiting the use of items consider as sacred. Sacred grooves are one of the valuable, but primitive practices of nature that plays an important role in biodiversity conservation. The present study was conducted to find out the effectiveness of taboos and cultural practices on biodiversity conservation in the Eastern Ghats of Tamil Nadu. Of the thirty-eight districts of Tamil Nadu, Salem and Tiruvannamalai districts were purposively selected based on the high tribal population. From each district, one block was selected namely the Pethanaickenpalayam block from Salem district and Jawadhu hills block from Tiruvannamalai district respectively. Totally 182 tribal respondents were selected by using the Proportionate Random Sampling method. The data was collected through a personal interview method by using well-structured interview schedule. Percentage analysis, and Cumulative Square Root of Frequency methods (Descriptive statistics) were used to analyze the collected data. Findings were meaningfully interpreted and relevant conclusions were drawn. Overall results show that above half (53.29 percent) of the respondents were found to have a moderate level of effectiveness with taboos and cultural practices on biodiversity conservation followed by more than two fourth (44.52 percent) of the respondents with a lesser level of effectiveness and only 2.19 percent of the respondents with a high level of effectiveness.

Tree species diversity and population structure in Tropical dry deciduous forest of Sri Lankamalleswara Wildlife Sanctuary, Southern Eastern Ghats, India.

Tree species diversity and population structure in Tropical dry deciduous forest of Sri Lankamalleswara Wildlife Sanctuary, Southern Eastern Ghats, India.

Petrographic Studies of a Part of East Coast Bauxite Deposits, Odisha, Eastern India and Implication on their Genesis

Abstract The East coast bauxite deposits of Odisha are well known in the mineral map of India. Some such deposits exposed at Nunapaimali, Sasubohumali and Baphlimali overlying khondalite of the Precambrian Eastern Ghats belt have been studied in respect of petrology, mineralogy and microstructure with a view to find out their genetic evolution. Bore hole samples from two former deposits and mine profile samples from Baphlimali revealed a good profile differentiation, in terms of three horizontal zones of variable thickness, which in descending order are: 1 to 29m laterite zone, 2 to 28m bauxite zone, 9 to 36m saprolite zone, comprising of lithomarge and partially lateritised khondalite [PLK] developed over host khondalite. Petrographic and mineralogical difference between these three zones, brought out through optical microscopy and XRD studies, further confirms the differentiation. Genetic evolution of bauxite is interpreted from the study of a large number of samples and results are collated from the photomicrographs appended in the paper. The authigenic bauxitisation was brought about by gradual dissociation of Al-silicate to Al-hydroxide minerals through different weathering cycles as indicated from their microstructural manifestations and mineral assemblages. Primary gibbsite is formed in the initial stage of weathering directly from Al-silicate minerals. Advanced stage of prolonged weathering converts the Al-silicate to kaolinite and then to secondary gibbsite. Grain size enlargement and recrystallisation showing mosaic habit, grain boundary migration and grain orientation are the outcome of digenesis. The weathering / lateritisation process continues, resulting in colloidal precipitation of gibbsite from pore water of lateritic residuum and is in progress even in recent period The Fe-oxide phases, represented by goethite and hematite are youngest in the paragenesis, and formed due to solution, precipitation and dehydration. Iron is mostly contributed by almandine garnet present in the host khohdalite. During chemical leaching, Fe gets released from garnet and occur either as FeOOH along its fractures or fill the weak planes / inter-granular space as secondary goethite. The goethite dehydrates to hematite during digenesis. Goethitisation and limonitisation particularly in the laterite zone are the results of supergene alteration.

Impatiens rosea (Balsaminaceae)- A new record for Odisha, India

Impatiens rosea Lindl., an Indian endemic species of family Balsaminaceae, collected from Mahendragiri hills of Odisha state (Eastern Ghats), is reported here for the first time from the state. A detailed description and photographs are provided for easy identification of the species.

Textural and Chemical Characters of Lean Grade Placer Monazite of Bramhagiri Coast, Odisha, India

The present study aims to investigate the textural, mineralogical and geochemical characteristics of lean grade placer monazite from the Bramhagiri beach sand deposit to assess the possibility for its use in industrial applications. The bulk back dune sand deposit with 18 samples showed the elements uranium and thorium in traces, phosphorus and calcium in minor amounts, and alumina, silica and titanium in major amounts. Since apatite was absent in this placer deposit, P and Ca were attributed to monazite only. Based on the chemical analysis, it was established that the monazite mineral exists in this deposit. The monazite is generally below the −150- to +90-micron size range, and the concentration of the monazite mineral in the bulk back dune sand is around 0.01% by weight. The structural data and complete chemical analysis established that the monazite is Ce-monazite. The monazites with other heavy mineral sands of the Bramhagiri beach placer deposits were derived from the Eastern Ghats, which closely resembles the mineralogical composition of khondalite, charnockite, leptynite and pegmatite groups of rocks. The Eastern Ghats’ provenance appears to be the primary source for the heavy mineral assemblages of the Bramhagiri placer deposit. Thus, these monazite sands are derived from the granulite facies of metamorphic rocks such as khondalites and charnockites from the Eastern Ghats group of rocks. Garnet is the major mineral, following ilmenite and sillimanite. Zircon, rutile and monazite are minor minerals in the deposit. All these minerals are well liberated and have uniform shapes with variable densities and size ranges, with different magnetic, electrical and surface properties. Hence, the occurrences of these heavy minerals are of economic importance. Further, these minerals can be recovered individually for industrial applications.

Elephants in the farm – changing temporal and seasonal patterns of human-elephant interactions in a forest-agriculture matrix in the Western Ghats, India

Accelerating levels of human-elephant conflicts (HEC) have become a topic of major concern in conservation efforts of endangered Asian elephants (Elephas maximus) throughout their range. Wayanad plateau (WP) is a key summer habitat of Asian elephants in the Brahmagri-Nilgiri Eastern Ghats elephant landscape (Nilgiris), harbouring the largest breeding population in Asia. With the increase in human population density and consequent forest loss, HEC amplified in frequency and intensity in Wayanad. We assessed the drivers of HEC in a temporal and spatial context by integrating questionnaire surveys, compensation claims for crop loss, and individual identification of crop-raiding elephants. The ordinal regression analysis showed that season and proximity to the forest boundary were the major drivers of conflict. The pattern of conflict is spatially heterogeneous, and there is peak crop depredation during the jackfruit and mango season (MayS-September), followed by paddy season (September-December). The conflict has resulted in the removal of jackfruit and mango trees from farmlands and stopped cultivation of several crops that attract elephants. This has impacted rural food supply, economic well-being, local biodiversity, and human-elephant coexistence. We discuss effective and locally appropriate conflict mitigation and management strategies which can apply in human-dominated landscapes.

A new species of rock-dwelling Hemidactylus Goldfuss, 1820 (Squamata: Gekkonidae) from the southern Eastern Ghats, India

A new large-bodied (SVL 101–109 mm) gecko of the genus Hemidactylus is described from the Gingee Hills in the Eastern Ghats of India. The new species is closely related to H. graniticolus and the recently described H. easai, from which it can be distinguished by its lower femoral pores count. The new species described here was previously identified as H. cf. graniticolus based only on the molecular data, pending its formal description. Our findings were consistent with the results from the molecular DNA analyses, showing that this population is morphologically distinct from other closely related species. As a result, we formally describe this lineage as a new species, providing a comprehensive description of its morphological characteristics based on a type series of five specimens and compare it with its congenerics.

Mechanical strength and nature of lithospheric deformation beneath the rifted sedimentary basins of the east India passive margin

The study of gravity signatures corresponding to sediment load over the passive margins is helpful to constrain the mechanical properties of continental rift systems as well as the adjacent ocean basins. Seismic reflection, free-air gravity and well information from the East India Passive Margin (EIPM) are investigated through spectral approach and 2D process-oriented gravity modelling for quantifying effective elastic plate thickness (Te) to understand the rift mechanisms and the sedimentary basins evolution. The characteristics of lithosphere within the major structural domains along the margin are quite variable. A narrow necking zone (40 km) in the southern segment, and approximately a 70 km hyper-thinned and exhumed domains are inferred in the central segment, while a narrow hyper-thinned domain (30–35 km) is observed in the northern segment of the margin. The southern segment of EIPM, adjacent to Southern Granulite Terrain has low Te values ranging from 5 to 10 km. The segment in the central margin, offshore Dharwar Craton has moderate Te values of 15–20 km. And the northern segment adjacent to onshore Eastern Ghats Mobile Belt has relatively high mechanical strength with Te values ranging from 25 to 35 km. The pattern of Te values and extent of major structural domains along the margin indicates that the southern, central and northern segments evolved as three different modes of rifting such as transform, hyperextended and hypoextended, respectively. In the oceanic domain, the lithospheric strength broadly increases with age following the thermal induced cooling plate model (600 °C isotherm). The thick sedimentary basin of the Bay of Bengal had attained the high value of elastic thickness (Te > 45 km) in the last 23 Myrs. The significant rheological strengthening of the oceanic lithosphere may be attribute to the following reasons: 1) increase in shear-wave velocity anomaly at a depth of 150 km and upper mantle density, 2) change in plate curvature caused by excessive deposition of Bengal Fan sediments in the deep ocean basins and subduction of oceanic plate under the Eurasian plate near the Bengal Fan and 3) modification of stress state of the lithosphere as a convergent interaction of the Indian plate with SE Asia.