Extensive valley lands in the Eastern Himalayas remain uncultivated after the rainy-season rice crop due to water seepage from surrounding hills, leading to reduced productivity and deterioration of soil health. Adopting organic farming with modified land configuration can enhance crop intensity, farm income, and several ecosystem services. Thus, the long-term field experiment was conducted, including 03 vegetable-based CS on raised beds and 08 rice-based sequences on sunken beds. The carrot-okra sequence achieved the highest mean rice equivalent yield (REY) and net return (NR), followed by potato-okra and French bean-okra, respectively. In sunken beds, the rice (cv. Shahsarang 1)-pea sequences had the highest pooled mean REY and NR. Long-term organic farming significantly (p < 0.05) improved soil chemical, physical, and biological properties under both raised and sunken beds, indicating better soil health for sustainable crop production. Further, the energy use efficiency and energy productivity were recorded as greater in the carrot-okra sequence and rice (Shahsarang-1)-pea under raised and sunken beds, respectively. More interestingly, the French bean-okra had the highest water productivity, followed by the potato-okra sequence. Thus, in a nutshell, the vegetable-based systems on raised beds and rice-legume systems on sunken beds emerged as more efficient and sustainable options for improving productivity, profitability, and ecosystem services in the fragile hill ecologies.

Abstract Rice (Oryza sativa L.) is known for its inherent tolerance to highly acidic soils, yet the underlying genetic and physiological mechanisms, particularly for iron (Fe) toxicity tolerance, remain insufficiently characterised. Although several quantitative trait loci (QTLs) and candidate genes (CGs) associated with Fe-toxicity tolerance have been identified, their fine mapping is unresolved. In this study, we performed a meta-QTL (M-QTL) analysis by integrating data from 11 QTL mapping studies and nine genome-wide association studies (GWAS), resulting in 63 M-QTLs with a minimum cluster size of two. The largest cluster comprised 10 QTLs, with an average cluster size of 4.01. Phenotypic variance explained (R2) ranged from 7% to 31% (mean 11.77%), and the average confidence interval (CI) was reduced from 4.68 to 2.12. Gene retrieval within these M-QTL regions identified 4,070 non-redundant genes. Comparison with 5 Fe-toxicity-related transcriptomic datasets revealed 897 differentially expressed genes, of which 284 were common to at least two datasets and designated as CGs. Characterisation of these CGs identified key regulatory elements, transcription factors, and transporters implicated in Fe tolerance. Notable CGs included OsNRAMP6, OsCDAP1, OsFRO2, OsFRDL2, OsPT2, OsPDR9, OsHSP70, OsACS2, OsZIP8, OsWRKY46, OsTIP2;2, OsGSTU17, OsINH2, and OsPEZ1. Association analysis identified 13 novel marker–trait associations (MTAs), and haplotype analysis revealed nine haplotypes (H001–H009). M-QTL1.6 and M-QTL7.3 were characterised by large QTL clusters and multiple candidate genes, while M-QTL10.1 contained an Fe-tolerance–associated haplotype within OsFRDL2. Key MTAs (MTA8, MTA16, MTA19, MTA24) formed central nodes in protein–protein interaction networks. This study identifies stable M-QTLs and favourable haplotypes associated with Fe toxicity tolerance in rice, offering clear genomic targets that regulate plant growth under excess iron stress.

Drought stress, intensified by climate change, represents a major limiting factor to growth, reproductive development, and nut productivity of cashew (Anacardium occidentale L.), especially in rainfed and marginal production systems. Identifying drought-tolerant cultivars and understanding their adaptive mechanisms are therefore critical for sustaining cashew productivity in water-limited environments. In this study, seventeen cashew varieties were evaluated under drought stress to identify tolerant genotypes and elucidate the physiological, biochemical, metabolic, and hormonal mechanisms underlying drought adaptation. A multi-trait genotype ideotype distance index (MGIDI) was employed to integrate diverse traits for robust genotype ranking and holistic drought tolerance assessment. The analysis identified ‘Priyanka’ and ‘Bhaskara’ as drought-tolerant varieties, whereas ‘Ullal-2’, ‘Vengurla-2’, and ‘Madakkathara-1’ were classified as drought-sensitive. Drought stress resulted in a significant reduction in nut yield (63.2%), accompanied by impaired nutrient uptake, reduced chlorophyll content (59.7%), and compromised membrane integrity, with more pronounced effects in sensitive varieties. In contrast, tolerant varieties showed increased antioxidant enzyme activities, including ascorbate peroxidase and polyphenol oxidase, along with increased accumulation of stress-responsive metabolites such as proline and soluble sugars, which contributed to improved oxidative stress mitigation and osmotic adjustment. Drought tolerance was further linked to differential accumulation of phenolic acids and flavonoids as well as higher endogenous levels of abscisic acid, jasmonic acid, and indole-3-acetic acid, all of which were positively correlated with nut yield under drought conditions. This integrated MGIDI-based assessment links coordinated physiological, metabolic, and phytohormonal responses to drought tolerance in cashew, offering robust selection criteria for breeding and deploying climate-resilient cultivars in drought-prone areas.

Eastern Himalayan Region (EHR), where rice is an important staple crop, developing drought stress tolerant varieties is crucial for improving yield and stability in variable climates. Genotype-by-environment (GEI) analysis is essential to understand the potential performance of the rice genotypes across environments. Present study investigated the stress responsive agro-physiological performance and stability of nine rice genotypes over two consecutive years across four distinct environments, with a focus of imparting wider climate stress resilience vis a vis augmented drought tolerance. Significant genotype-by-environment interactions were observed for 16 agro-physiological traits based on likelihood ratio test analysis. Stability and multi-trait selection were assessed using Weighted Average of Absolute Scores (WAASB) and Smith-Hazel index-based models. Genotypes, Tripura Chikan Dhan (G9), TRC-2015-10 (G5) and TRC-2015-17 (G6) were identified stable and high yielding with superior physiological traits, based on WAASB based methods. Genotypes Nagina-22 (G2) and TRC-2015-17 (G6) were identified as desirable based on the Smith-Hazel index and TRC-2015-17 (G6) outperformed all other genotypes in terms of yield and physiological traits, as determined by both WAASB based methods and Smith-Hazel method. The genotype, TRC-2015-17 (G6) exhibited the high grain yield (25.5 g/plant) along with superior physiological traits, including maximum root length (99.53 cm), root volume (132.7 cm3), and flag leaf thickness (0.22 mm). These findings emphasise the potential of Tripura Chikan Dhan (G9), TRC-2015-10 (G5) and TRC-2015-17 (G6) and ushering the scope for revalidating the same across diverse and challenging hill agro-ecologies to strengthen future breeding programme.

Homegardens are multifunctional agroforestry systems that support livelihood security, biodiversity conservation, and climate change mitigation in the tropics. However, quantitative assessments of their ecological attributes across elevation gradients remain limited in Northeast India. This study evaluated species diversity, structural characteristics, vegetation biomass, and carbon stocks of homegardens across three elevation zones (E1: <250 m, E2: 250–500 m, and E3: >500 m amsl) in subtropical Nagaland. A multistrata vegetation structure comprising 130 plant species was observed, with trees accounting for 47.59% of the total species composition. Mean homegarden area declined significantly from 988.17 ± 181.63 m² at lower elevations (E1) to 291.46 ± 35.70 m² at higher elevations (E3) (p < 0.05). The Shannon diversity index showed no significant variation across elevations, whereas species richness and evenness increased significantly with elevation. Aboveground biomass, total biomass, and total biomass carbon exhibited non-significant increasing trends along the elevation gradient, ranging from 65.38 to 69.74 Mg ha⁻¹, 78.71 to 83.99 Mg ha⁻¹, and 36.99 to 39.48 Mg C ha⁻¹, respectively. In contrast, soil organic carbon (SOC) stock increased significantly from 58.93 ± 1.33 Mg C ha⁻¹ at E1 to 93.64 ± 3.61 Mg C ha⁻¹ at E3 (0–60 cm depth). The findings indicate that biodiversity and vegetation carbon storage were influenced more by management practices and species composition than by elevation alone, while soil carbon dynamics were strongly associated with elevational variation. Overall, homegardens of Nagaland function as important reservoirs of biodiversity and carbon while supporting household livelihoods.

Context The Eastern Himalayan region exhibits strongly acid soils due to pedogenesis and topographical matrices under a sustained high precipitation regime. Prevalence of diverse and spatially varied land-use systems is a fundamental characteristic across these montane ecosystems and plays a key role in its impact on different soil nutrient pools. Aim The study was conducted to elucidate the impact of varied land use systems on nutrient mineralisation dynamics, including carbon (C) and its associated pools. Methods Throughout 14 selected land use systems, a random stratified sampling method was utilised with 56 quadrats that were exposed layer-wise down to a soil depth of 1.0 m. ResultThe analytical results indicated that the land use systems had a significant impact on soil pH. Likewise, total organic C (TOC) content showed significant variation (P < 0.01) across land uses (0.40-4.61%) and down the soil profile. Irrespective of land use type, the soil profile to a depth of 0.60 m had high TOC concentration (2.35-6.01%) and C-mediated microbial biomass nutrients (26.7-688.1 mu g g(-1)). The bacterial and fungal populations were concentrated at the top 0.6 m, but suddenly decreased beyond that depth. Conclusion The association and clustering pattern of soil properties and different land use types, identified through principal component analysis, suggested that forest areas and oak, alder, and apple plantations favoured increases in microbial biomass, enzyme activities, and viable bacterial populations.

Maize is a major crop of the Eastern Himalayan Region (EHR) which faces significant environmental challenges including waterlogging (WL) under changing climate. Through microcosm and field experiments, this study aimed to evaluate the phenotypic plasticity and adaptive mechanisms of maize landraces under WL conditions at the seedling and flowering stages. Based on the response coefficient and waterlogging tolerance coefficient 14 landraces at the seedling stage were found to be WL tolerant whereas RCM-12-19, RCM-32-19, and RCM-16-19, emerged as WL tolerant at both stages. At seedling stage, Root Length ratio (RLR) has increased under WL stress to the tune of 98.4 % while Root Mass Ratio (RMR) has ranged from 0.09 to 0.47 for control and from 0.10 to 0.55 under WL. Root:shoot ratio varied from 0.10 to 0.88 and 0.11-1.23 under control and WL, respectively and a total of 19 genotypes reflected tolerance trait under WL. Phenotyping of key root traits (brace root angle (BA1), branching, and crown root number) revealed their substantial contribution to stress resilience, as confirmed by principal component analysis (PCA) and regression models. PCA indicates, for root tissue density (RTD) and root fineness (RF) at seedling stage, genotypes like RCM-34-19, RCM-10-19, RCM-23-19, RCM-42-19, and RCM-31-19 are closely associated with the second principal component (PC2). Whereas, at flowering stage, RCM-39-19, RCM-52-19, RCM-34-19, RCM-32-19, RCM-2-19, RCM-43-19, RCM-5-19, RCM-45-19, RCM-47-19, and RCM-50-19 exhibited strong positive loadings on (PC2) for the trait BA1. The results indicate that brace- and crown roots exhibit genotype-dependent architectural plasticity, which reduces the metabolic cost of soil exploration by increasing BA1, branching of brace roots (BB), and the number of brace roots (BO) while decreasing above-ground whorls (BW); thereby improving nutrient uptake from topsoil under WL stress. RCM-12-19, RCM-32-19, RCM-16-19, and RCM-23-19 demonstrated rapid root growth and branching after WL stress at the flowering stage, supporting their potential for breeding WL-tolerant maize. These findings align with the "steep, cheap, and deep" (SCD) root ideotype, where reduced crown root number and deeper root architecture improve nutrient uptake and yield. Genotype RCM-11-19 apart from scoring high through visual scoring was also found to have the highest dry biomass (76.7 g plant-1) and grain yield (12.2 g plant-1) under WL conditions. This research identifies critical root traits and promising genotypes for developing WL-tolerant maize, contributing to sustainable crop production in rain-fed EHR environments.

Understanding the physico-chemical properties of biochar is crucial for optimizing its use as a soil amendment to enhance crop growth. This study focuses on biochar produced from three types of biomass prevalent in the eastern Himalayan region: pine wood residue, maize stalk, and mixed weeds. The biochar was applied to soil at different rates (0, 5, 10, and 20 t ha−¹) to evaluate its effects on soil properties and French bean yield. The results revealed that mixed weed biochar (MWB) and maize stalk biochar (MSB) had alkaline pH values (9.83 and 9.31, respectively), whereas pine residue biochar (PRB) was acidic with a pH of 5.84. Notably, PRB contained 23–49

Tomato is a highly sensitive crop to moisture stress, and grown widely under varying conditions of moisture deficit. To identify the stable genotypes and characterize their responses to moisture stress, thirty-two diverse genotypes were evaluated at three imposed moisture regimes i.e., sub-optimal irrigation at 75±5% of the field capacity (FC; L1), irrigation at 50±5% of the FC (L2), and irrigation at 25±5% of the FC (L3) inside a passively ventilated plastic greenhouse. A wide range of variability was observed for 23 analyzed physio-chemical traits under study. All the analysed traits (except root-shoot ratio, chlorophyll index, total biomass, sugar content, and acidity) have shown higher heritability and moderate to high genetic advance, indicating that these traits are governed by additive gene action and responsive to selection under water stress conditions. All the growth and yield parameters were shown to decrease significantly with the increase of intensity of moistures stress. Likewise, physiological parameters, namely chlorophyll and the relative water content tended to decrease, while the rate of water loss and proline content tended to increase following an increase in stress level. Fruit quality traits like total sugar, vitamin-C, and lycopene contents were tended to improve with the increase of designated moisture stress. The additive main effects and multiplicative interaction (AMMI) analysis of variance revealed the significant effects of moisture stress, genotype, and genotype × environment interaction for yield and yield-related traits. Based on multi-trait stability index (MTSI) analysis, MT-11, VL Tomato-4 and Megha Tomato-3 were considered most stable and promising genotypes for promotion for commercial production under the moisture stress conditions.

A field experiment was conducted to phenotype the root traits and screen 35 local maize landraces of Eastern Himalayan region for waterlogging tolerance at seedling and flowering stage. Microcosm screening was done at seedling stage (6-8 leaf stage) with pots maintained with flooded water to a level of 4-5 cm above the soil surface for 15 days continuously. Artificial flooding stress to a depth of 20-25 cm above the soil surface for 10 days continuously was induced at the time of flowering in the field. This was majorly performed to trace the plasticity of root architecture through phenotyping. The evaluation and selection of different maize landraces for waterlogging stress at seedling stage was established through shovelomics with the apparent calculation of response coefficient (RC) as rightful/ surrogate indication of phenotypic plasticity and waterlogging tolerance coefficient (WTC). For assessing the field performance, each stress responsive trait viz., BW, BO, BA1, BA2, BB, CN, CA and CB were assigned scoring values from one to nine visually which ideally serve as screening measure for waterlogging tolerance. The results revealed that genotypes RCM-44-19, RCM-16-19, RCM-39-19, RCM-42-19, RCM-15-19, RCM-51-19, RCM-9-19, RCM-45-19, RCM-32-19, RCM-43-19, RCM-10-19, RCM-49-19, RCM-12-19 and RCM-26-19 were identified as WL tolerant at seedling stage and some genotypes like RCM-12-19, RCM-32-19, RCM-16-19 and RCM-23-19 showed vigorous root growth and branching after waterlogged treatment at flowering stage. The genotypes like RCM-12-19, RCM-32-19 and RCM-16-19 were designated as flooding stress tolerant at both the crop growth stages which could be of appropriate utility for the upcoming maize breeding program under excess moisture-prone environments of North East hilly regions after systematic validation through advance molecular tools.

The marginal Himalayan ecosystems have great potential for biochar application for conserving soil moisture, ameliorating soil acidity, improving soil fertility, and thus, contributing to sustainable intensification. Thus, the efficacy of biochar was tested along with nutrient management practices (NMP) on the performance of maize (Zea mays L.)-French bean (Phaseolus vulgaris L.) as the emerging cropping system in an acid soil under rainfed hill ecosystem. The rainy season maize was grown with three levels of biochar (0, 2.5, and 5 Mg ha-1, applied only once in the first year), and four NMP (100% recommended dose of fertilizer [RDF] [80:60:40 N:P2O5:K2O kg ha-1], 75% RDF, 75% RDF + 4 Mg ha-1 farm yard manure [FYM], and 50% RDF) under minimum tillage. After harvesting of maize, French bean was grown under no-till with four NMP (100% RDF [50:60:40 N:P2O5:K2O kg ha1], 75% RDF, 75% RDF + 4 Mg ha-1 FYM, and 50% RDF). The soil properties after 3 years viz., soil moisture, soil organic carbon (SOC), pH, and available N, P, and K status were significantly improved under 5 Mg ha-1 biochar than no biochar. Among the NMP, 75% RDF + FYM and 100% RDF had higher soil moisture, water infiltration, pH, SOC concentrations, and available N, P, and K status than others. The interaction effect of 5 Mg ha-1 biochar and 75% RDF + 4 Mg ha-1 FYM registered the highest SOC content (15.7 g kg-1). Available N was the highest in soil under 75% RDF + 4 Mg ha-1 FYM whereas, available P in soil under 100% RDF. Application of 5 Mg ha-1 biochar produced significantly the highest mean grain yield of maize and succeeding French bean. The combined application of 100% RDF and biochar 5 Mg ha-1 produced the highest maize equivalent yield. Thus, 5 Mg ha-1 biochar and application of recommended fertilizers are suggested for sustaining soil fertility and sustainable intensification of rainfed hill agriculture under acidic soil.

Rice (Oryza sativa L.) is the major staple crop of Eastern Himalayan Region (EHR) and its cultivation and productivity is severely constrained by elevated temperature (T) in cooler mountain regions like EHR. Present study on stress physiological response of indigenous rice cultivars (68no.) of EHR for elevated T of Carbon dioxide temperature gradient chamber (CTGC) revealed that leaf chlorophyll and leaf T has varied significantly with chlorophyll content index (CCI) of 35.05 and 28.34 °C canopy temperature (CT) and range of 25.0–49.3CCI and 23.1–35.9 °C CT. Higher chlorophyll of 35.02–40.0 CCI and cooler canopy T of 26.0–29.0 °C under elevated T was recorded by 45.0

Yield potential of maize having distinct genetic diversity in Eastern Himalayan Region (EHR) hill ecologies is often limited by Al toxicity caused due to soil acidity. Stress physiological analysis of local check exposed to 0-300 mu M Al under sand culture revealed that 150 mu M Al as critical and 200 mu M Al as tolerable limit. Increase in Al from 0 to 300 mu M reduced total chlorophyll, carotenoids by 74.8 % and 44.7 % respectively and enhanced anthocyanin by 35.3 % whereas LA, SLW and SL have reduced by 81.3%, 21.3 % and 47.8 % respectively. R/S ratio was 51.0 and 13.7 % higher at lower Al levels (50 mu M and 100 mu M) and photosynthetic, transpiration rate and TDM were 62.5 %, 42.9 % and 78.6 % lower at higher Al (300 mu M) as compared to control. TRL, RSA, RDW and RV at higher Al (300 mu M) were 92.6 %, 98.7 %, 78.7 and 97.5 % lower over control respectively. Root and shoot Al and PUpE at higher Al (300 mu M) was 194.0, 69.2 and 830 % higher whereas PUE decreased to 88.5 % over control. Evaluation of 31 indigenous maize cultivars at 0, 150, and 250 mu M Al in sand culture, alongside tolerance scoring and assessment, revealed that Megha-9, Megha-10, and MZM-19 exhibits high Al tolerance, Megha-1, MZM-22, and MZM-42 demonstrated moderate tolerance, whereas Uruapara, Sublgarh, and BRL Para were identified as Al-sensitive. Stress physiological parameters like SDW, TDM, TRL, SL and LA contributed 46.02 % of variability to PC1, whereas A, RV, RSA, anthocyanin and Chlorophyll_b, contributed 13.56 % of variability to PC2. Highest values of CMS, SL, LP, LA, TRL and anthocyanin were recorded in cluster I having sensitive cultivars while highest CMS, SL, LA, LP, TRL and RSA were found in cluster II having moderately tolerant cultivars and highest mean values for TRL, RSA, LP, LA, CMS and SL were recorded in cluster III having highly Al stress tolerant cultivars. The traits viz., A, RV, RSA, anthocyanin and Chlorophyll_b, total chlorophyll and TDM were emanated as physio-morphological for assessing Al toxicity stress tolerance in Maize with high divergence values. Tolerant cultivars showing 63.4 % and 22.4 % higher anthocyanin at 150 mu M Al and 250 mu M Al than moderately tolerant one in acid soil experiment with increased root Al, shoot Al, root P and shoot P by 42.6 %, 11 %, 95.1 % and 34 % respectively were emerged as promising for novel maize improvement under acid soils of EHR.

Global warming is causing increased temperatures that are affecting crop yield and sustainability. To harness the diversity present in rice germplasm, 1100 rice genotypes from the north-eastern Himalayan region (NEHR) were evaluated for high yield stability and marker-trait associations using SSR markers under ambient and elevated temperature conditions in the CO2-temperature gradient chamber (CTGC). Compared to ambient temperature, most agro-morphological traits showed a decreasing trend under elevated temperature, while PCV, GCV, heritability, and GAM tended to increase with elevated temperature. Pollen fertility percentage ranged from 5.4 to 99.4

The majority areas of valley lands in the Himalayan foothills remains fallow after the rice harvest. Recycling of plant biomass with conservation tillage may help in enhancing soil water availability, crop physiological function and productivity under moisture stress hill environments of this region. The present study focused on three tillage practices viz., no-till (NT), minimum tillage (MT) and conventional tillage (CT) and five nutrient management (NM) practices viz., 100 % NPK, 50 % NPK, 50 % NPK + in-situ residue retention (ISRR), 50 % NPK + weed biomass (WB) and 50 % NPK + green leaf manure (GLM) in rice and their residual effect on physiobiochemical properties, yield attributes and produce quality traits of succeeding pea varieties (Arkel and Prakash). Results revealed that total leaf chlorophyll content in vegetable pea varieties Arkel and Prakash was 12.0 and 11.5 % higher under no-till (NT) followed by 11.9 and 10.6 %, respectively under minimum tillage (MT) as compared to conventional tillage (CT) in rice. Similarly, application of 50 % NPK+ green leaf manure (GLM) and 50 % NPK+ weed biomass (WB) enhanced total leaf chlorophyll content in pea by 6.50-8.17 % and 3.93-5.48 % for pea varieties Arkel and Prakash, respectively. Photosynthetic rate and leaf dry weight were found 40.4 and 80.2 % higher under MT in Arkel whereas transpiration rate (E) and shoot dry matter were 33.1 and 19.3 % higher in Prakash under MT. Leaf water potential and root-to-shoot ratio were found 22.6 and 16.5 % higher in Prakash under MT and NT compared to CT respectively. Leaf temperature and stomatal conductance were 8.67 % lower and 9.8 % higher under MT in Prakash respectively as compared to CT, whereas 4.8 and 13.0 % higher under 50 % NPK +GLM and 50 % NPK+WB as compared 100 % NPK. Leaf cell viability was 22.5 and 20.1 % higher under MT whereas leaf MDA content was 29.9 and 28.3 % higher under MT in Arkel and Prakash respectively. Leaf relative water content was significantly higher to the tune of 25.7 and 22.4 % under NT compared to CT whereas leaf cell membrane integrity was 41.3 and 40.4 % higher under NT for Arkel and Prakash. Higher pod protein was noticed under MT along with 50 % NPK+GLM (13.1 %), whereas total soluble sugar was recorded highest under NT with 50 % NPK+GLM (21.1 %) in Prakash and MT with 50 % NPK+GLM (18.3 %) in Arkel. However, in both varieties, lower TSS was recorded under CT and with 50 % NPK (14.2 and 11.2 %) and the reducing sugar was maximum under the application of 50 % NPK+WB as compared to 100 % NPK alone. For both varieties of pea, green pod yield was recorded highest under MT (4.76 & 5.89 t/ha) as compared to CT (4.76 & 6.17 t/ha) and NT (4.76 & 5.55 t/ha). While 50 % NPK+WB has recorded significantly highest green pod yield of Arkel, 50 % NPK+ GLM has caused the highest yield of Prakash. PCA executed on physiological traits explained the total variability to the tune of 85.50 %, thereby extracting three PC's viz., PC 1 (62.63 %), 12.58 %) and 10.28 %, respectively. Thus, the adoption of MT in rice followed by NT in winter pea with the application of 50 % NPK+WB or 50 % NPK+GLM is promising for better physiological traits and subsequently favoring the grain yield of pea under stressful hill environments of Eastern Himalaya.

Under changing climate, identification and diversification of cropping systems having higher stress resilience and adaptability for fragile mountain ecosystems of Eastern Himalayan Region (EHR) are paramount. Lesser known and underutilized crop like buckwheat (BW) with year-round cultivation potential and having higher stress tolerance to prevailing stresses (low pH, low moisture) could be a crop of choice for abating malnutrition among hill inhabitants. Proper time of sowing of the crop is between mid-September and mid-December seemingly essential for better grain yield to the tune of 15.0–18.0 q ha−1, and the crop is found suitable to be grown all through the year for higher green biomass (12.6–38.4 q ha−1). Enhanced exudation of low-molecular-weight organic acids (LMWOA) like oxalic acid by buckwheat increased the solubilization of fixed forms of free phosphorus (P) to the extent of 35.0 to 50.0 micro gram per plant in ideal acid soil of the region (P) in acid soil. In addition, relatively increased resilience to moisture stress with improved stress physiological attributes adds more potentiality for enhancing cropping intensity of hill slopes of EHR. Few genotypes namely IC377275 (18.97q ha−1), IC26591 (17.1 qt ha−1), IC14890 (16.32q ha−1), and Himapriya (15.27q ha−1) are emerging as high-yielding types for productive cultivation in acid soils. Studies on the combined effects of acid soil and moisture stress would aid in novel crop improvement of buckwheat in EHR.

The Indian Himalayan Region (IHR) is considered as a "bowl of biological hotspots" as it has diverse and endemic species of plants and animals. It includes 12 Indian states i.e., Jammu and Kashmir (J&K), Himachal Pradesh (HP), Uttarakhand (UK), Assam (AS), Arunachal Pradesh (AP), Meghalaya (ML), Nagaland (NL), Tripura (TR), Manipur (MN), Sikkim (SK), and West Bengal (WB). It extends over 2500 km from the east (AP) to west (J&K) across 250–300 km as width, contributing 16.2% by land to the country area and supporting 3.86% of the population, i.e., 51 million. The anthropogenic activities such as conventional farming system, soil erosion and degradation, wide destruction of forest, and intensive agricultural practices to sustain the ever-increasing population affect the ecological diversity and the livelihoods and food security of the IHR. These activities also deteriorate the soil's organic and inorganic carbon stocks and so impact soil health and ultimately soil productivity. The major reason for the reduction in soil carbon stocks in IHR is due to the slash and burn of forest for "Jhumming cultivation." This not only affects the soil quality but also releases carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), nitrous oxide (NOx), etc., as greenhouse gases (GHGs) to the atmosphere and thus affects climate change.

Context or problem: Root rots, a major factor contributing to yield loss in chickpea, often occur in disease complexes.Objective or research question: Plant responses to disease complexes are not well elucidated. We sought a clear understanding of a newly identified disease complex in chickpea, dry root rot (DRR)-wilt disease complex, in the field and studied the effect of drought on the severity of the complex and its effect on yield. We compared plant responses to DRR alone and the disease complex under drought and determined the phytohormones involved in plant defense against the disease complex.Methods: We compared the effect of 14 environments (two soil moisture regimes at seven locations) on the incidence of the disease complex and yield loss in four chickpea genotypes. We also studied the effect of drought on rhizospheric and root endo-microbial communities by whole-genome and metagenomic sequencing and performed LC-MS-based phytohormonal profiling of chickpea roots. Results: Soil moisture and plant genetic variability were critical in modulating disease incidence in field conditions. DRR was the primary driver of the disease complex under drought stress. Drought aggravated the yield reductions caused by the disease complex from 35% to 60% in susceptible genotypes. Further, drought-tolerant genotypes performed better under combined disease complex infection and drought stress and exhibited lesser yield losses than susceptible genotypes. Pathogenic fungi such as Macrophomina phaseolina, Fusarium oxysporum, and Rhizoctonia solani were enriched in the chickpea rhizosphere, and M. phaseolina was predominant in infected chickpea roots under both well-watered and drought conditions. Symbiotic associations of chickpea with nitrogen-fixing bacteria were suppressed under drought stress. Abscisic acid, jasmonic acid, and salicylic acid were found to be involved in defense against the disease complex across various stages of plant growth. Implications or significance: We highlight the interaction between drought and soil pathogens affecting chickpea yield and suggest the utilization of drought-tolerant root traits as donor traits for improving combined stress resistance. We also demonstrate growth stage-dependent phytohormonal responses elicited by DRR and the DRR-wilt disease complex. The identification and management of root rots is essential, and our findings offer valuable new insights into a lesser-known but highly significant disease complex of chickpea.Data availability statement: Manuscript data is available at Supplementary File S1. The soil microbe whole-genome and metagenome and root-microbe 16 S and ITS sequencing data are available at NCBI PRJNA871091 and PRJNA895851.

Introduction Under a changing climate, the fragile ecosystems of the Eastern Himalayas (EH) are persistently challenged by prolonged dry spells and erratic rainfall. Identification of suitable high-yielding crops with higher moisture stress tolerance and adaptability is paramount for the region. Although the region received a good amount of rainfall in the rainy season, the winter months, viz., November to March, rarely received any rain. Even within the rainy season, there are several intermittent drought spells that hinder crop productivity. Methods The present study has used field and microcosm experiments to assess the year-round cultivation potential and extent of moisture stress tolerance in the lesser-known buckwheat crop of the region. Results and discussion Sowing of buckwheat from mid-September to mid-December produced better grain yield, the highest being when sowing in October (9.83 q ha −1 ) and the crop was found suitable to grow all through the year for higher green biomass (12.6–38.4 q ha −1 ). The moisture stress tolerance of buckwheat was significantly enhanced by increased total root length and root surface area by 12.4 and 34.7%, respectively. Increased photo-protective carotenoids, chlorophyll b, and favorable stomatal attributes with substantial epicuticular wax have significantly improved the moisture stress tolerance of Buckwheat. In addition, leaf proline was found 25.4% higher and total soluble protein, reducing sugar, and cell membrane stability were found 29.2, 38.1, and 36.5% lower compared to the control, respectively. A significantly lower rate of water loss (25.6%) with its stomatal and non-stomatal adaptations and versatile pollen structural traits under moisture stress over control, make the buckwheat crop potentially more stress tolerant and economical crop for EH of India.