North Eastern Himalayan Research Articles

Dissecting genetic variation for agro-morphological traits of elevated temperature under CO2-temperature gradient chamber and validation of markers linked to heat tolerance of rice (Oryza sativa L.)‏ cultivars of north-eastern Himalayan Region

Dissecting genetic variation for agro-morphological traits of elevated temperature under CO2-temperature gradient chamber and validation of markers linked to heat tolerance of rice (Oryza sativa L.)‏ cultivars of north-eastern Himalayan Region

Acute poisoning with Jatropha curcas in North Eastern Himalayan region – A case series and review of literature

Plant poisoning is one of the common accidental sources of poisoning amongst the villagers and the troops going on long-range patrolling. Seeds of Jatropha curcas a/k/a biodiesel pant mimicking nuts are an uncommon source of poisoning, manifesting as mainly gastrointestinal symptoms and less frequently the other systemic manifestations. Here, we report a case series of two cases of serving soldiers who presented with gastrointestinal symptoms after consumption of seeds of unknown plants mimicking nuts, which was later identified as J. curcas. Both patients had favorable outcomes with syndromic management of the unknown poisoning.

Phylogenetic and population genetic analysis of Arunachali Yak (Bos grunniens) using mitochondrial DNA D-loop region.

The Arunachali yak (Bos grunniens) is an important breed native to the northeastern Himalayas of India. Understanding its genetic diversity and evolutionary relationships with other bovine species is crucial for effective conservation and breeding strategies. This study investigates the mitochondrial DNA (mtDNA) D-loop region of Arunachali yak and compares it with other bovines to elucidate these relationships. We collected blood samples from 18 Arunachali yak individuals and isolated genomic DNA. The partial mtDNA D-loop region was amplified using PCR and sequenced. Sequences were compared with those from Bos frontalis, Bos gaurus, Bos indicus, Bubalus bubalis, and Capra hircus available in GenBank. Phylogenetic relationships were assessed through Neighbor-Joining trees and median-joining networks. Genetic diversity indices and neutrality tests were applied to evaluate population genetic characteristics. Phylogenetic analysis identified three distinct clades, with Arunachali yak clustering closely with Bos indicus, and forming a separate branch from other bovine species. Median-joining networks revealed six haplogroups, with Arunachali yak uniquely representing Hap_3. Genetic diversity analysis showed no polymorphism within Arunachali yak, indicating very low genetic variation in the selected animal samples. AMOVA demonstrated significant genetic differentiation among populations (Fst = 0.30053, P < 0.001), with a substantial portion of variation occurring within populations. The Arunachali yak exhibits a close genetic relationship with Bos indicus, reflecting recent divergence. The study underscores the distinct genetic profile of Arunachali yak and highlights its limited genetic variability. These findings enhance our understanding of bovine evolutionary relationships and emphasize the need for targeted conservation measures to preserve the genetic integrity of Arunachali yak.

Assessment of active tectonics of the Tripura-Mizoram fold belt (Surma Basin), North East India

The Tripura-Mizoram fold belt is situated in the north-eastern part of India. Northeastern Himalaya including this region is tectonically very active, partly petroliferous, and has international attention from academicians and industry persons. This study aims at locating areas of recent tectonic vulnerability. Drainage networks are proxies of active faulting. Changes in geomorphic indices e.g., long profile analysis, basin-scale parameters, stream length gradient index and steepness index along the rivers in the eighteen watersheds extracted within the study area are evaluated. The Index of active tectonics (IAT) derived from the basin-scale parameters is classified into five classes: Class 1 (IAT =1.875–2.000), Class 2 (IAT = 2.001-2.375 ), Class 3 (IAT = 2.376-2.750), and Class 4 (IAT = 2.751-3.250) and Class 5 (IAT = 3.000‐3.320). Class 1 indicates the highest activity of tectonics. The tectonic sensitivity is also marked in micro-scale where rivers cross lineaments / faults. Elevations from source to mouth of individual consequent rivers of each watershed indicate the most vulnerable sections where the channels run along and across the faults or lineaments in watersheds 2, 14 and 15. The computed R2 values and the IAT identify watershed 2 and watershed 15 as the tectonically most active. Well-bore stability issue from the Petroleum mining lease (PML) blocks needs to be taken care from watershed 2, 3 and 15.

Multivariate Data Analysis Assisted Mining of Nutri-rich Genotypes from North Eastern Himalayan Germplasm Collection of Perilla (Perilla frutescens L.).

Understanding the nutritional diversity in Perilla (Perilla frutescens L.) is essential for selecting and developing superior varieties with enhanced nutritional profiles in the North Eastern Himalayan (NEH) region of India. In this study, we assessed the nutritional composition of 45 diverse perilla germplasm collected from five NEH states using standard protocols and advanced analytical techniques. Significant variability was observed in moisture (0.39-11.67%), ash (2.59-7.13%), oil (28.65-74.20%), protein (11.05-23.15%), total soluble sugars (0.34-3.67%), starch (0.01-0.55%), phenols (0.03-0.87%), ferric reducing antioxidant power (0.45-1.36%), palmitic acid (7.06-10.75%), stearic acid (1.96-2.29%), oleic acid (8.11-13.31%), linoleic acid (15.18-22.74%), and linolenic acid (55.47-67.07%). Similarly, significant variability in mineral content (ppm) was also observed for aluminium, calcium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, molybdenum, sodium, nickel, phosphorus, and zinc. Multivariate analyses, including hierarchical clustering analysis (HCA) and principal component analysis (PCA), revealed the enriched nutritional diversity within the germplasm. Correlation analysis indicated significant positive and negative relationships between nutritional parameters, indicating potential biochemical and metabolic interactions present in the perilla seeds. TOPSIS-based ranking identified promising genotypes for functional foods, pharmaceuticals, and nutritional applications. This study provides a first in-depth report of the nutritional composition and diversity of perilla germplasm in the NEH region, thus aiding in the identification of superior varieties for food and nutritional diversification and security.

Synergistic impact of climate and land use land cover change dynamics on the hydrological regime of Loktak Lake catchment under CMIP6 scenarios

Study region: Loktak Lake catchment, north-eastern Himalayan ranges, IndiaStudy focus: Assessing the potential synergistic impact of land use land cover (LULC) and climate change on water resources is crucial for watershed management especially in the data-scarce vulnerable wetlands. Using the SWAT hydrological model, the current study seeks to quantify the combined impacts of LULC and climate change on the water balance parameters of the Loktak Lake catchment. This study simulates the hydrological regime of the Loktak Lake catchment based on future climate and changes to LULC dynamics using four GCM models in combination with SWAT models under two alternative scenarios.New hydrological insights for the region: The findings showed that under the SSP 126 and SSP 585 scenarios, the annual mean temperature is anticipated to increase by a maximum of 1.7°C and 3.74°C, respectively, by the 2050 s and 2090 s, while the annual precipitation similarly shown a rising trend for both the scenarios for the mid and far future. The mean annual streamflow is projected to increase by 48.84 cumecs (31.65 %) and 57 cumecs (36.89 %) by the 2050 s and 2090 s decades, respectively, while the water yield will rise by 200.65 mm (30.25 %) and 216.1 mm (32.57 %) in comparable decades. The outcomes of this study might provide a scientific foundation for ecological protection as well as water resource management and development in response to the potential future risk due to climate change in the Loktak Lake catchment.

&lt;I&gt;Pronephrium cuspidatum&lt;/I&gt; (Bl.) Holtt. - New to India from Nicobar Islands with Notes on Confused Related Taxa

Pronephrium cuspidatum (Bl.) Holtt. originally known from Malesia has been actually reported for the first time from Nicobar Islands, India and the Indian material earlier known as Meniscium cuspidatum Bl. represented Pronephrium nudatum (Roxb. ex Griff.) Holtt. and P. lakhimpurensis (Rosenst.) Holtt. from North-Eastern Himalayas. The current nomenclature and illustrations for the present species with key to the taxa earlier confused in Indian literature have been provided.

New Indian species of Dacus Fabricius (Diptera: Tephritidae: Dacinae: Dacini) similar to Dacus crabroniformis (Bezzi), endemic to the Western Ghats and Northeastern Himalayas

Two new species of Dacus Fabricius, namely D. (Mellesis) nagarathnae Abhishek, David &amp; Hancock, sp. nov., from Meghalaya and D. (Mellesis) venkateshi Abhishek &amp; David, sp. nov., from the Western Ghats of India are described and illustrated. The Nepalese D. (Callantra) succaelestis Ito is newly synonymized with D. (Mellesis) polistiformis (Senior-White). An updated illustrated key to the 22 species of Dacus now known from the Indian Subcontinent is provided and attractant responses are listed.

Unique genetic architecture of prolificacy in 'Sikkim Primitive' maize unraveled through whole-genome resequencing-based DNA polymorphism.

'Sikkim Primitive' maize landrace, unique for prolificacy (7-9 ears per plant) possesses unique genomic architecture in branching and inflorescence-related gene(s), and locus Zm00001eb365210 encoding glycosyltransferases was identified as the putative candidate gene underlying QTL (qProl-SP-8.05) for prolificacy. The genotype possesses immense usage in breeding high-yielding baby-corn genotypes. 'Sikkim Primitive' is a native landrace of North Eastern Himalayas, and is characterized by having 7-9 ears per plant compared to 1-2 ears in normal maize. Though 'Sikkim Primitive' was identified in the 1960s, it has not been characterized at a whole-genome scale. Here, we sequenced the entire genome of an inbred (MGUSP101) derived from 'Sikkim Primitive' along with three non-prolific (HKI1128, UMI1200, and HKI1105) and three prolific (CM150Q, CM151Q and HKI323) inbreds. A total of 942,417 SNPs, 24,160 insertions, and 27,600 deletions were identified in 'Sikkim Primitive'. The gene-specific functional mutations in 'Sikkim Primitive' were classified as 10,847 missense (54.36%), 402 non-sense (2.015%), and 8,705 silent (43.625%) mutations. The number of transitions and transversions specific to 'Sikkim Primitive' were 666,021 and 279,950, respectively. Among all base changes, (G to A) was the most frequent (215,772), while (C to G) was the rarest (22,520). Polygalacturonate 4-α-galacturonosyltransferase enzyme involved in pectin biosynthesis, cell-wall organization, nucleotide sugar, and amino-sugar metabolism was found to have unique alleles in 'Sikkim Primitive'. The analysis further revealed the Zm00001eb365210 gene encoding glycosyltransferases as the putative candidate underlying QTL (qProl-SP-8.05) for prolificacy in 'Sikkim Primitive'. High-impact nucleotide variations were found in ramosa3 (Zm00001eb327910) and zeaxanthin epoxidase1 (Zm00001eb081460) genes having a role in branching and inflorescence development in 'Sikkim Primitive'. The information generated unraveled the genetic architecture and identified key genes/alleles unique to the 'Sikkim Primitive' genome. This is the first report of whole-genome characterization of the 'Sikkim Primitive' landrace unique for its high prolificacy.

Soil organic carbon fractionation, carbon index, and microbial activity under different agroforestry systems in North Eastern Himalayas, India.

The potential of soil organic carbon fractions for agroforestry systems (AFSs) is not well understood. Five distinct AFSs were tested for its impact on soil organic carbon fractionation, carbon index, and microbial activity in North Eastern Himalayas, India. The mean labile carbon (LC) ranged from 4.55 to 5.43kg soil-1 across the land use systems. Napier system observed the lowest very labile carbon (VLC) 12.36kg soil-1 in 60-75-cm depth. The mean non labile carbon (NLC) ranged from 15.67 to 16.83gkg soil-1 across the land use. Highest less labile carbon (LLC) was observed in agri-horti-silviculture (AHS) followed by agri-silvi-horticulture (ASH) land use system. The black gram + mandarin + Alnus nepalensis land use recorded higher lability index (1.66) followed by maize + Schima wallichii (1.65) in 0-15-cm depth. Among the different land use systems, carbon pool index increased in all the depths over buckwheat + mandarin. The mean carbon management index (CMI) value ranged from 167.02 to 210.12 among the land use system. The mean CMI was highest in black gram + mandarin + Alnus nepalensis (210.12) followed by soybean + Ficus hookerii + guava (191.56), maize + Schima wallichii (281.71), and lowest in buckwheat + mandarin (167.02). Among the AFSs, black gram + mandarin + Alnus nepalensis showed greater amount of carbon pool index, lability index, and carbon management index and, hence, considered the best sustainable agroforestry system to sequester more carbon in the Sikkim Himalaya. Such system also retained more different organic carbon fractions. The mean CMI value ranged from 167.02 to 210.12 among AFSs. Acid phosphatase activity was more during the rainy season followed by winter and summer season. Similar trends were followed by the urease activity in all the three seasons. Overall conclusion from this investigation is that SOC fractions, carbon index, and microbial activity levels are strongly influenced by the prevailing agroforestry systems.

Genetic diversity and population structure analysis in Job's tears (Coix lacryma-jobi L.) collections from northeastern Himalayan region

Genetic diversity and population structure analysis in Job's tears (Coix lacryma-jobi L.) collections from northeastern Himalayan region

Investigation of fire regime dynamics and modeling of burn area over India for the twenty-first century.

The characteristics of the vegetation fire (VF) regime are strongly influenced by geographical variables such as regional physiographic settings, location, and climate. Understanding the VF regime is extremely important for managing and mitigating the impacts of fires on ecosystems, communities, and human activities in forest fire-prone regions. The present study thereby aimed to explore the potential effects of the confounding factors on VF in India to offer actionable and achievable solutions for mitigating this concurring environmental issue sustainably. A global burn area (250m) data (Fire-CCIv5.1) and fire radiative power (FRP) were used to investigate the dynamics of VF across seven different divisions in India. The study also used the maximum and minimum temperatures, precipitation, population density, and intensity of human modification to model forest burn areas (including grassland). The Coupled Model Intercomparison Project-6 (CMIP6) was used to predict the burn area for 2030 and 2050 future climate scenarios. The present study accounted for a sizable increasing trend of VF during 2001-2019 period. The highest increasing trend was found in central India (513 and 343 km2year-1 in the forest and crop fire, respectively), followed by southern India (364 km2year-1 in forest fire), and upper Indo-Gangetic plain (128 km2year-1 in crop fire). The FRP has varied significantly across the divisions, with the north-eastern Himalayas exhibiting the highest FRP hotspot. The maximum and minimum temperatures have the greatest influence on forest fires, according to Random Forest (RF) modeling. The estimated pre-monsoonal burn area for 2050 and 2050 future scenarios suggested a more frequent forest fire occurrence across India, particularly in southern and central India. A comprehensive forest fire control policy is therefore essential to safeguard and conserve forest cover in the regions, affected by forest fire periodically.

Morpho-biochemical diversity in tree tomato (Solanum betaceum Cav.) genotypes grown under different altitudinal locations of north eastern Himalayas of India

Morpho-biochemical diversity in tree tomato (Solanum betaceum Cav.) genotypes grown under different altitudinal locations of north eastern Himalayas of India

Geospatial Analysis of Seismotectonics for Microearthquake Hazard Zonation in Kohima District, Northeastern Himalayan Region of India

Geospatial Analysis of Seismotectonics for Microearthquake Hazard Zonation in Kohima District, Northeastern Himalayan Region of India

Anthropogenic climate change accelerating monsoon hydrological hazards in Northeastern Himalayan region of India: geospatial approach

Anthropogenic climate change accelerating monsoon hydrological hazards in Northeastern Himalayan region of India: geospatial approach

Deciphering Forest Cover Losses and Recovery (1990–2022) Using Satellite Data in Behali Reserve Forest of Northeastern Himalaya

Deciphering Forest Cover Losses and Recovery (1990–2022) Using Satellite Data in Behali Reserve Forest of Northeastern Himalaya

Dual carbon isotope-based brown carbon aerosol characteristics at a high-altitude site in the northeastern Himalayas: Role of biomass burning

PM2.5 samples (n = 34) were collected from January to April 2017 over Shillong (25.7°N, 91.9°E; 1064 m amsl), a high-altitude site situated in the northeastern Himalaya. The main aim was to understand the sources, characteristics, and optical properties of local vs long-range transported carbonaceous aerosols (CA) using chemical species and dual carbon isotopes (13C and 14C). Percentage biomass burning (BB)/biogenic fraction (fbio, calculated from 14C) varied from 67 to 92 % (78 ± 7) and correlated well with primary BB tracers like f60, and K+, suggesting BB as a considerable source. Rain events are shown to reduce the fbio fraction, indicating majority of BB-derived CA are transported. Further, δ13C (−26.6 ± 0.4) variability was very low over Shillong, suggesting it's limitations in source apportionment over the study region, if used alone. Average ratio of absorption coefficient of methanol-soluble BrC (BrCMS) to water-soluble BrC (BrCWS) at 365 nm was 1.8, indicating a significant part of BrC was water–insoluble. A good positive correlation between fbio and mass absorption efficiency of BrCWS and BrCMS at 365 nm with the higher slope for BrCMS suggests BB derived water-insoluble BrC was more absorbing. Relative radiative forcing (RRF, 300 to 2500 nm) of BrCWS and BrCMS with respect to EC were 11 ± 5 % and 23 ± 16 %, respectively. Further, the RRF of BrCMS was up to 60 %, and that of BrCWS was up to 22 % with respect to EC for the samples with fbio ≥ 0.85 (i.e., dominated by BB), reflecting the importance of BB in BrC RRF estimation.

Delineation of high‐resolution soil carbon management zones using digital soil mapping: A step towards mitigating climate change in the Northeastern Himalayas, India

AbstractDelineation of carbon management zones (CMZs) by capturing geospatial distribution of soil organic carbon (SOC) stock down the profile is an effective strategy for precision agriculture and climate change mitigation. Satellite (Landsat OLI 8), terrain (SRTM 30 m DEM) and bioclimatic (WorldClim dataset) factors were used as covariables in this digital soil mapping approach. Depth harmonization using the quadratic spline method (equal‐area) was carried out prior to quantile regression forest (QRF) algorithm‐based modelling to estimate SOC stock at six standard soil depths (0–5, 5–15, 15–30, 30–60, 60–100 and 100–200 cm). Soil depth and SOC stock for the whole soil profile were used for the delineation of CMZs using fuzzy k‐means clustering. The predicted SOC stock, varied from 14.68 to 42.35 Mg ha−1 in the top layer (0–5 cm depth), while 17.91 to 36.88, 14.15 to 34.70, 12.55 to 35.59, 10.30 to 28.52 and 7.26 to 20.16 Mg ha−1 in the depths of 5–15, 15–30, 30–60, 60–100 and 100–200 cm, respectively. The QRF algorithm performed well in predicting SOC stock with high R2, which ranged from .67 to .83 for all the soil depths. To delineate three CMZs, modified partitioning entropy and the fuzzy performance index were used. In CMZ2, there was a significant increase in SOC stock, followed by CMZ1 and CMZ3. This zone (CMZ2) was located in the central region of the study area and was mostly covered by dense forest and perennial plantations (rubber). The CMZs provided the necessary foundation for the development of site‐specific carbon management techniques that can enhance ecosystem service and meet climate change mitigation goals.

Stability of organic carbon pools and sequestration potential as affected under different agroforestry systems

There are few data on the possibility of soil organic carbon sequestration for agroforestry systems (AFSs). Rarely are the effects of AFSs established for the regeneration of carbon in degraded soils of the Indian North Eastern Himalayas (susceptible to soil erosion, carbon and nutrient loss) examined. The effects of five different AFSs on the stability of organic carbon pools and sequestration potential were evaluated at the ICAR-Sikkim Centre. Black gram + mandarin + Alnus nepalensis had the lowest bulk density at all depths. The highest oxidizable carbon was observed in the black gram + mandarin + Alnus nepalensis system, followed by soybean + Ficus hookerii + guava, maize + Schima wallichii, and soybean + Ficus hookerii + guava, followed by Napier. Regardless of soil depth, the buckwheat + mandarin system had a noticeably lower SOC than the other systems. The total soil organic carbon gradually decreased with increasing depth of the soil profile. According to the results, there was little difference in the total active carbon pool in the 0–90 cm depth among the various systems; however, when compared with Buckwheat + Mandarin, it varied significantly (P ≤ 0.05). The mean passive carbon pool in soils ranged from 22.4 to 25.1 Mg ha−1 across the land use in the 0–90 cm depth. The least soil microbial biomass carbon (MBC) was observed during the winter season in all systems at different soil depths. The maximum MBC was recorded at 0 to 15 cm depth (476.2 – 302.5 µg dry soil−1). By simultaneously cultivating kinds of trees with several uses and agri-horticultural crops, a large-scale adoption of AFSs may replace carbon lost via the development of the crop in degraded soils and offer a viable choice for livelihood.

Effect of nutrient management practices on zinc concentration and grain, straw yield of Paddy

Rice is the predominant staple crop in developing countries in which zinc i.e., one of the essential micronutrients required in small amounts (5-100 mg/kg) in plant is mostly found deficient. The experiment was conducted with different nutrient sources along with microbial inoculants in the kharif season, 2016 at the research farm of ICAR research complex for the Northeastern Himalayan region situated at Barapani, Meghalaya in split-plot with three types of nutrient management practices viz,. organic, integrated nutrient management and inorganic (RDF) in the main plot and three microbial inoculants viz., Azospirillum, zinc solubilizing bacteria and phosphorus solubilizing bacteria in a subplot in split plot design replicated thrice. Grain yield and Zn uptake was found highest in INM and Azospirillum+PSB+ZnSB. On the other hand, Zn content was found highest in organic source and in Azospirillum+PSB+ZnSB.