Phosphorus (P) fixation in aerobic rice cultivation severely limits crop productivity. However, the mechanisms by which arbuscular mycorrhizal fungi (AMF) regulate phosphate transporter (OsPT) gene expression across genetically diverse varieties under variable soil P regimes remain poorly understood. A controlled pot experiment was conducted to examine six aerobic rice genotypes, CR Dhan 201, CR Dhan 204, CR Dhan 205, CR Dhan 207, IR 36 (P-susceptible), and Kasalath IC459373 (P-tolerant), under three soil P levels (low: 2.68 ppm, medium: 8.81 ppm, and high: 12.84 ppm) with and without AMF inoculation. AMF colonization was significantly higher (50.19-63.63%), and sporulation was greater (24.29-30.28 spores per 50 g soil) in CR Dhan 204, CR Dhan 205, and CR Dhan 207 under low and medium soil P. All AMF-inoculated varieties showed 33-55% improvement in root architecture and 14.87-50.22% higher P uptake compared to uninoculated controls under P-deficient conditions. Ten of the 13 phosphate transporter genes (OsPT2, OsPT3, OsPT4, OsPT6, OsPT8, OsPT9, OsPT10, OsPT11, OsPT12, and OsPT13) were upregulated in CR Dhan 207 under low soil P conditions with AMF, and the broadest gene activation profile was observed across all varieties. These findings establish that AMF-mediated regulation of the OsPT gene network is strongly variety-dependent and most pronounced under P-limited conditions, positioning CR Dhan 207 as a priority genotype for mycorrhiza-assisted phosphorus management in aerobic rice systems.

Dietary fibres, especially non-starch polysaccharides including β-glucan and arabinoxylan from cereal grains, are vital for human health due to their role in lowering cholesterol, regulating glycaemic index, and reducing the risk of chronic diseases like type II diabetes. A daily intake containing 2% or more β-glucan is often associated with health benefits. Wheat (Triticum aestivum L.), a staple crop and major source of dietary carbohydrates, contains limited variability for these fibre components compared with its wild relatives. To explore genetic resources for fibre biofortification, we evaluated a panel of 478 wheat genotypes including 37 wild relatives, 6 tetraploid, and 435 hexaploid wheat accessions for β-glucan, arabinoxylan, alongside protein, and starch content. The panel showed wide variation, with mean values of 0.93% for β-glucan, 5.77% for arabinoxylan, 13.37% for protein, and 68.51% for starch. Among wild relatives, Aegilops peregrina and Aegilops kotschyi emerged as superior sources of high β-glucan and arabinoxylan, whereas modern cultivars generally exhibited lower values. Significant positive correlations were observed between β-glucan and protein, and negative associations with starch and thousand-grain weight, indicating potential trade-offs in grain composition. These findings highlight the untapped potential of wild genetic resources for enhancing the nutritional quality of wheat and provide promising candidates for pre-breeding and biofortification strategies aimed at improving dietary fibre in staple foods.

Understanding the changes in soil organic carbon (SOC) content over time under varying environmental and management conditions is important for refining strategies for the maintenance of soil health and achieving sustainable crop production systems. In the present investigation, the RothC 26.3 model has been tested for studying SOC turnover under four tillage and crop residues management scenarios in a long-term rice-wheat cropping system for 13 years in the lowland Terai region of India. Data collected from 13 cycles of long-term rice-wheat permanent plots laid out in a randomized block design were used in this study. Estimates of measured and modelled SOC contents were considered under four different scenarios: Scenario 1-Zero tillage, Scenario 2-Conventional tillage, Scenario 3-Zero tillage + Crop residue mulching, and Scenario 4-Conventional tillage + Crop residue incorporation. Linear correlation between estimates of measured and modelled carbon (C) pools revealed that the RothC 26.3 model was suitable for long-term C estimation in the lowland Terai region. The study predicted that practising Scenarios 3 and 4 improved SOC by 30.9

Biological nitrification inhibitors are compounds present in plant root exudates which suppress the activity of soil nitrifiers, thereby inhibiting nitrification process. Biological nitrification inhibition (BNI) trait has been recognized in various crops including rice. However, its association with nitrogen use efficiency under sub-humid tropical conditions has not been explored. The present study attempted to evaluate the BNI potential of crude root exudates from contrasting nitrogen-use efficient (NUE) rice cultivars, Sabita (low NUE) and CR Dhan 310 (high NUE). A hydroponic-based methodology was developed to optimize plant growth and maximize extraction of root exudates. Biochemical profiling of exudates was studied through Fourier transform infra-red (FTIR) spectroscopy. Exudates were then evaluated in three phases (broth assays, soil incubation, and pot experiment) by analyzing ammonia monooxygenase (amoA) gene abundance, nitrification inhibition potential (NIP), community-level physiological profiling (CLPP), BNI capacity, and nitrous oxide (N2O) flux. FTIR analysis revealed the functional groups consistent with chemical classes previously associated with rice BNI, including phenolic acids and aliphatic diols. CR Dhan 310 exudates reduced the bacterial amoA gene abundance compared to Sabita, and showed 38.5% more NIP than control and at par with dicyandiamide. The CLPP of root exudates revealed selective inhibition of Nitrosomonas europaea without altering beneficial culturable microbial communities. In pot experiment, CR Dhan 310 reduced potential nitrification rates, amoA gene abundance, and N2O-N fluxes compared to Sabita. Overall, the results demonstrate an association between BNI trait of CR Dhan 310 root exudates and its higher nitrogen-use efficiency, highlighting the potential for sustainable nitrogen management.

Meta-analysis-based publications have gained considerable importance in the recent decade. Similar studies of techniques and management practices convey the findings more emphatically. However, limited meta-analysis studies have been published to date on the impacts of conservation agriculture (CA) on soil biological parameters in the Indian subcontinent. To address this gap, we collected data from 35 publications and 412 paired observations on CA vs. conventional tillage (CT) during the period from 2000 to 2020, based on soil biological parameters. We analyzed the data using the software Meta-Win 2.1 at p < 0.05 significance level. The result showed higher microbial biomass (MB) and enzyme activities under CA over CT practice. The MB carbon (MBC), MB nitrogen (MBN), dehydrogenase, fluorescein diacetate hydrolysis, β-Glucosidase activity, and Urease increased by 14, 19, 25, 18, 26, and 19

Chickpea (Cicer arietinum L.) productivity is heavily constrained by major biotic stresses, particularly Fusarium wilt, Ascochyta blight and Botrytis gray mold, which collectively cause significant annual yield losses worldwide. To develop a refined understanding of the genetic architecture underlying resistance to these pathogens, a comprehensive meta-analysis was conducted using 113 QTLs taken from 24 independent studies, including diverse mapping populations. This analysis led to the identification of 27 MQTLs, which represent both novel genomic regions and, crucially, refined positions of previously known QTLs with reduced confidence intervals. Four robust Breeders’ MQTLs were identified on the basis of high phenotypic variance (PVE ≥ 10

Arsenic (As) contamination in rice poses a serious health concern, particularly for communities that depend on rice as a primary dietary staple. Developing rice varieties with consistently low As content has proven difficult using traditional breeding methods, highlighting the need for novel approaches. Targeting genes responsible for As accumulation in rice could be a key strategy to address this issue. In this study, we explored whether editing the silica transporters genes OsLsi1 and OsLsi2, responsible for co-transporting As in rice, could reduce As accumulation while maintaining grain yield. Using CRISPR/Cas9 technology, we targeted the promoter and N-terminal coding regions of these genes, to produce homozygous transgene-free edited lines. Expression analysis revealed that the mutations led to a 2-3.5-fold and a 5-70-fold decrease in the expression of OsLsi1 and OsLsi2 transcripts, respectively, in rice roots. Both mutant and wild-type lines were exposed to silicic acid (5 mM) and sodium arsenite (10 µM) in short-term hydroponic experiments to assess the uptake of arsenic and silicon (Si) in their roots and shoots. The results showed a significant reduction in As (21-32

Introduction: To address the urgent demand for biofortified wheat enriched with health-beneficial dietary fibres such as β-glucan, this study employed meticulous crossbreeding between established wheat cultivars and the β-glucan-rich wild relative Aegilops kotschyi accession “AK-3790”. Methods: Within this context, a derivative line encompassing a pair of 7U chromosomes from Ae. Kotschyi, denoted as 63-2-13, was identified. The presence of the 7U chromosome in this line was confirmed through comprehensive molecular marker and genomic in situ hybridization (GISH) analyses. With the aim of increasing the β-glucan content in hexaploid wheat, two distinct backcross populations were developed utilizing the 63-2-13 line as the donor parent and two separate recurrent parents (WH1105 and HD3086). These populations underwent an exact selection regimen, encompassing parent-like phenotypes, heightened yield, and robust resistance to yellow rust, meticulously tracked across successive generations until the BC2F2:3 stage. Results and Discussion: Notably, among the outcomes, selected BC2F2:3 progenies presented remarkable increases in β-glucan levels, with a notable increase (BC2F2:3 23-5) resulting in an impressive increase in the 1.76% grain β-glucan content. Despite a discernible reduction in yield compared with their high-yielding counterparts, BC2F2:3 23-5 demonstrated a harmonious trait profile, encompassing heightened β-glucan content and moderate yellow rust resistance, thus positioning it as a compelling candidate for subsequent refinement endeavors. This research notably underscores the substantial potential of precise introgression strategies for increasing the β-glucan content in wheat, thereby underscoring the imperative of adept trait optimization to ensure both yield stability and nutritional enhancement.

This study investigated the effects of Azolla supplementation on the productivity, milk composition, reproductive performance, and economics of lactating Murrah and Nili-Ravi buffaloes in Hanumangarh district, Rajasthan, a semi-arid region. Forty lactating buffaloes and twenty buffalo calves were randomly assigned to four groups, with Azolla supplementation levels of 0% (Control), 10% (T1), 15% (T2), and 20% (T3) in their concentrate mixture. The study lasted 90 days for buffaloes and 3 months for calves. The basal diet consisted of green fodder (sorghum/berseem) and dry fodder (wheat straw), with Azolla partially replacing the concentrate mixture. Results indicated that Azolla supplementation significantly increased milk yield, with T3 (20% Azolla) yielding 9.1 L/day, compared to 7.8 L/day in the control group. Milk composition also improved, with significant increases in fat, protein, and SNF content in the T2 and T3 groups. Reproductive parameters showed marked improvement, including reduced service period (120–125 days), improved conception rate (78–80%), and shortened calving interval (405–410 days) in Azolla-fed groups. Calf growth performance also benefitted from Azolla supplementation, with calves in the T3 group gaining 34.5 kg over 3 months, compared to 25.8 kg in the control group. Feed efficiency was enhanced, with feed conversion ratio (FCR) improving from 10.5 kg DM/kg gain in the control group to 8.2 kg DM/kg gain in the T3 group. Azolla supplementation also reduced feed costs, decreasing the cost of milk production from ₹23.1/L in the control group to ₹20.3/L in the T3 group, while net returns per buffalo increased from ₹240/day to ₹272/day. This study demonstrates that Azolla supplementation, particularly at 15–20%, can significantly improve milk production, reproductive efficiency, calf growth, and economic profitability in buffaloes. Azolla is a promising, cost-effective feed resource that can replace expensive protein concentrates, especially in semi-arid regions with limited feed resources.

Most soils in the eastern tropical region of India are moderately to strongly acidic and poor in available phosphorus and organic matter. Low soil fertility greatly affects the production of fruit crops such as dragon fruit, since the crop has high nutrient requirements due to the long fruiting period. Under these circumstances, arbuscular mycorrhizal fungi (AMF) can effectively improve nutrient availability and ensure quality fruit production. The present study is envisioned to assess the effectiveness of mycorrhiza on soil enzyme activity, shoot mineral profile and fruit quality attributes of dragon fruit. A composite native culture of Glomus was applied at 25, 50 and 100 g plant−1 along with two levels of P (25 and 50 g plant−1) in dragon fruit. Application of 50 g AMF with 25 g P (M50P25) significantly enhanced root colonization; activities of soil enzymes such as phosphatase, urease, dehydrogenase and fluorescein diacetate; and shoot nutrient content. Root colonization, soil enzyme activity and shoot nutrient content exhibited a significant correlation. Fruit weight, pulp content, pulp firmness, soluble solid contents, reducing sugar, sucrose, protein, ascorbic acid, betacyanin, phenol, flavonoid and antioxidant activity were also significantly higher under M50P25. Principal component analysis also exhibited proximity of M50P25 with soil enzyme activity, nutrient content and fruit quality attributes of dragon fruit. However, inoculation of 100 g AMF with 25 g P (M100P25) also exhibited prominence in influencing soil enzyme activity, nutrient uptake and the fruit quality of dragon fruit.

The elemental concentrations/profile in plants is mainly influenced by various factors including genotype, species, and the environment. The extent of toxic elements and the soil and rice plant mineral composition in the rice growing region of Haryana, India is not known. To discern rice genotypes for nutritional and toxic element profiles, we gathered 58 indica rice genotypes cultivated across soils with pH levels ranging from 6.29 to 7.92. Sampling from 11 diverse sites in Haryana during the kharif seasons of 2020–2021 and 2021–2022, we analysed the concentration of 29 elements using Inductively Coupled Plasma Mass Spectrometry. Our investigation unveiled substantial disparities in elemental concentrations among genotypes from distinct locations, underscoring the influence of genetic, physiological, and environmental factors on ionomic variations. Notably, total Arsenic (As) and Cadmium (Cd) concentrations in grains spanned from 0.017 to 1.17 mg kg-1 and 0.03 to 0.66 mg kg-1dry weight, respectively. Alarmingly, several genotypes surpassed the Codex international standard’s proposed limit of inorganic As at 0.20 mg kg-1. Correlation analysis revealed significant disparities among elements across samples, illuminating diverse degrees of positive and negative interactions. Principal component analysis further indicated that ionomic alterations across genotypes predominantly stemmed from variations in soil-to-plant transport pathways. The study underscores that even within plants of identical genotypes, shifts in soil conditions trigger ionomic variations. Moreover, the associations primarily revolve around genotype screening for multi-element accumulation effects, offering insights for breeders to develop biofortified rice varieties with safe levels of hazardous elements like As and Cd.

Carbon (C) sequestration in soils primarily relies on the management of soil organic C (SOC). In the lowland Terai region of tropical eastern India in the lower ranges of the Himalayas receiving > 3000 mm rainfall annually, managing SOC using different soil and crop management strategies is challenging. This study aimed to assess the long-term effects of conventional tillage (CT), zero tillage (ZT), crop residue (R) incorporation/mulching, and application of biofertilizers (B) on soil C sequestration and yield sustainability in the annual rice-wheat cropping system in the Terai region. In the 16th cycle of a long-term rice-wheat experiment with eight treatments (ZT, ZTR, ZTB, ZTRB, CT, CTR, CTB, and CTRB) in permanent plots laid out in a complete randomized block design, soil samples from different treatment plots were analyzed for various pools and fractions of soil organic C, SOC stocks, C sequestration and C retention efficiency. Soil organic C in the best-performing treatment (ZTRB) increased by 17

Conservation agriculture practices have been developed for rice-based cropping systems in eastern India to mitigate the negative effects of continuous monocropping. However, the effects of individual and combined conservation agriculture components on carbon (C) and nitrogen (N) mineralization, soil enzyme activities, and C and N fractions are unknown. This study aimed to evaluate the effects of key components of conservation agriculture such as, reduced tillage, crop residue retention and crop diversification both individually and in combinations with the control making 8 treatments, on soil carbon and nitrogen dynamics under direct seeded rice-green gram system. Reduced tillage alone and in combination with diversification resulted in 10

Microbial-driven dissimilatory nitrate reduction to ammonium (DNRA) is a unique pathway in the terrestrial nitrogen (N) cycle. It helps to retain N within the soil, preventing its loss to the surrounding environment. Due to the frequent flooding and draining, rice ecosystems experience both aerobic and anaerobic conditions, causing a shift in microbial process. Our goal in the present study was to understand the influence of various environmental factors and their regulatory mechanisms of DNRA pathway and also assess the nrfA gene-targeted (marker functional gene of DNRA) microbial community under diverse upland and lowland rice agro-ecosystems in sub-humid tropical condition. Investigated rice agro-ecosystems for the present study were i) irrigated (IR), ii) three lowland, based on water depth i.e., shallow lowland: 0–30 cm; intermediate lowland: 30–50 cm; semi-deep lowland: 50–100 cm, and iii) two upland (dry or rainfed and aerobic) conditions. Soil physico-chemical and extracellular enzymatic activities, microbial dynamics and metabolism, nrfA-gene targeted metagenome, and both absolute and expressional quantification of nrfA-gene were performed and analysed under these diverse rice agro-ecosystems. Our findings showed that the DNRA activity was significantly (p < 0.05) correlated with the C/N ratio in arable paddy soil, which suggested that DNRA activity might be possible in diverse rice agro-ecosystems apart of anoxic reducing conditions. Biolog ecoplate-based study revealed that among different carbon guilds, amino acids utilising microbial community was more in semi-deep lowland compared to other rice agro-ecosystems. Interestingly, a higher ( 20.44

In cereal-based agro-ecosystems, improving nitrogen use efficiency (NUE) and minimizing environmental degradation depend on efficient nitrogen (N) management. Although synthetic nitrification inhibitors (SNI) are employed to slow down nitrification, their limitations related to high cost, phytotoxic effects, and environmental concerns necessitate the adoption of alternate strategies. Biological nitrification inhibition (BNI) is a natural plant-driven phenomenon, offering an eco-friendly and sustainable substitute for SNI that involves the production of chemicals from roots and shoot extracts that inhibit the activity of soil nitrifying microbes. This review synthesizes current knowledge on BNI in cereal crops and introduces innovative perspectives by integrating microbial interactions, cropping system design, and genetic enhancement. BNI responsive cereal crops, such as rice (1,9-Decanediol, syringic acid), sorghum (sorgoleone, sakuranetin), wheat, and maize (zeanone, benzoxazolinone derivatives), produce a variety of inhibitory compounds. The biosynthesis and release of these compounds are influenced by crop genotype, microbial communities, plant growth stages, soil pH, and nutrient status. In this review, we examine how BNI traits are expressed at the genetic and physiological level and discuss breeding strategies like chromosomal introgression that can improve the BNI potential of elite cultivars. Furthermore, we examine how BNI shapes the rhizospheric microbial communities and how its potential integration into low-input systems, intercropping, and crop rotations can be beneficial. A systems-level perspective is provided, positioning BNI as a point of confluence between soil ecology, plant genetics, and sustainable nutrient management. Additionally, we identify potential directions to accelerate field-scale implementation of BNI in climate-resilient agriculture under current climatic projections.

Climate change as a global issue is characterized by alterations in assessable parameters of climate and other environmental factors, at an alarming rate. These factors are potent enough in modifying the existing dynamics of soil microbiomes in crop fields. Recent studies highlight that the formation of microbial communities associated with roots is selectively influenced by the host plants. Advancements in molecular technologies like high throughput sequencing and ecological network analysis have proved to be revolutionary tools in revealing the microbial diversity, structural community, and their interactions along with determining their habitat affinities with the changed environmental factors. Altered environmental factors like elevated CO2, high temperature, imbalanced fertilizer application, change in moisture regimes, pesticide pollution, etc. have been discussed in this chapter along with their influence on the paddy soil microbiome. A shift in the establishment patterns, diversities, community structure, and functioning is observed significantly owing to these climatic and environmental variations. Crops gradually tend to acclimatize to different adverse external stress conditions generated by environmental change factors using their inbuilt biological mechanisms. The plant and its microbiome interact with each other through different metabolic pathways and form stress tolerance strategies. This chapter, therefore, aims to outline the major environmental change factors and how they have affected the soil microbes, their community composition, and functioning abilities in paddy fields, along with addressing some of the mitigation strategies mediated by microbes in soil nutrient cycle.

Azolla is an aquatic fern that has a symbiotic association with nitrogen-fixing cyanobacteria. It is mainly used as a biofertilizer in rice; however, its potential under salt-affected rice cultivated area was compromised. Therefore, the present study was undertaken to understand the effect of salinity stress on morpho-physiological, biochemical characteristics, photosynthetic efficacy, nutrient and High Affinity Potassium Transporter (HKT) genes in Azolla. The results indicated that out of 102, 8 Azolla (A. microphylla, BLCC 5, BLCC 18, BLCC 28, Pa Car WTY, R 18, R 54 and R 59) were found tolerant to 80 mM NaCl. The best species for salt tolerant (80 mM NaCl) was A. microphylla, whereas the least-tolerant was A. rubra. Fresh biomass production, frond length and width in A. microphylla were significantly (p < 0.05) higher in A. microphylla than A. rubra in both 40 and 80 mM NaCl. Moreover, chlorophyll a/b ratio, carotenoids and chlorophyll fluorescence (CHF)-derived FO, Fm, Fv/Fm and root architecture (root length, average root diameter, root volume, projectile and surface area) were higher in A. microphylla than A. rubra under 40 and 80 mM NaCl. Contents of Na+ and Ca2+ increased in both A. microphylla and A. rubra, which can interfere with the uptake of essential macronutrients; however, these were accumulated comparatively less in A. microphylla than A. rubra, whereas a reverse trend was observed in cellular accumulation of K+ content. A. microphylla had higher superoxide dismutase (SOD), ascorbate peroxidase (APX), and proline activities in 40 and 80 mM NaCl than A. rubra. For the first time, twenty six HKT primers were designed as a molecular marker to identify salt-tolerant Azolla. Out of these, three HKT primers (Req 6, Aeq14, and Aeq16) were amplified in A. microphylla under NaCl stress, while their amplifications were not observed in A. rubra (salt susceptible). In A. microphylla, the expression of the Req 6 (HKT) gene were more under NaCl stress. Moreover, further research is needed to discover and validate the biochemical and molecular processes that confer salinity tolerance in Azolla plants.