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The yellow stemborer, Scirpophaga incertulas , is a monophagous pest of rice, attacking the crop from its vegetative to reproductive stages. Microorganisms are crucial in influencing the insect’s life cycle, evolution, and ecology, presenting an avenue for understanding and improving management strategies. Present research employed advanced next-generation sequencing technology to investigate the microbiota of S. incertulas , a previously unexplored area for developmental stage associated microbial diversity. The study used 16 S rRNA V3–V4 region amplicon sequencing to determine the diversity of bacteria associated with different developmental stages of S. incertulas . Taxonomically, bacterial communities were classified into 25 phyla, encompassing 46 classes, 101 orders, 197 families, and 364 genera. The major phyla identified were Proteobacteria (39%), Firmicutes (39%), Actinobacteria (11%), and Bacteroidetes (7%), with Proteobacteria being the most predominant across all developmental stages except the larval stage, where Firmicutes took precedence. Moraxellaceae, Bacillaceae, Xanthomonadaceae, Sphingobacteriaceae, and Flavobacteriaceae were predominant families across all the developmental stages. However, in the egg and adult stages, the abundance of Bacillaceae was notably lower, whereas Prevotellaceae found significantly higher in adult stages. Dominant genera across all stages included Acinetobacter , Bacillus , Lactobacillus , Enterococcus , and Pseudomonas . The result showed that the highest number of Operational Taxonomic Units (OTUs) were in the larval stage (426 OTUs), the lowest in adults (251 OTUs), and the egg stage (254 OTUs). This suggests that the microbiota may play a role in the growth and development of S. incertulas . The predicted functional assessment of the associated S. incertulas microbiota revealed that the microbiota primarily participated in metabolic pathways, secondary metabolite biosynthesis, energy metabolism, signaling, and cellular processes. Our findings shed light on the significant variations in the microbial community and their predicted functions present in S. incertulas across developmental stages. The present study findings will help in developing novel microbiota-based management strategies.

Background Rice production faces relentless threat from the brown plant hopper ( Nilaparvata lugens ), particularly in Asian subcontinents like India, where the highly damaging biotype-4 is prevalent. Developing rice varieties with long-lasting resistance is crucial to combat this threat sustainably. This study aimed to identify stable novel resistant sources and associate molecular markers with resistant loci present in the new sources of resistance. In this study, 152 rice genotypes were screened against N. lugens , and further genotyping was done using 82 SSR (Simple Sequence Repeat) markers linked to 28 N. lugens -resistant genes and QTLs. Results After continuous screening for three seasons, 33 resistant rice genotypes (score 1) were identified. Unlike susceptible genotypes, resistant genotypes exhibited lower plant damage, nymphal survival, and honeydew excretion, with ranges of 4.60–8.90%, 11.50–24.00%, and 3.43 to 7.43 cm², respectively. However, resistant genotypes showed more feeding marks, ranging from 22.67 to 32.00 plant − 1 . Genetic analysis indicated an average genetic diversity of 0.150 and a polymorphic information content of 0.128 for the markers. Cluster and population structure analyses classified the genotypes into three primary genetic groups. This grouping was corroborated by Principal Coordinate Analysis (PCoA), which separated susceptible, moderately resistant, and resistant genotypes into distinct components. Additionally, 87% of the genetic variation was between individuals of the populations and 13% between populations. Conclusion Marker-trait association analysis using generalized linear models (GLM) and mixed-linear models (MLM) identified two markers viz. RM1313 ( Bph9 ) and RM7 ( Qbph3 ) were significantly associated with phenotypic parameters related to N. lugens resistance. Among these RM7 ( Qbph3 ) was identified by both GLM and MLM analyses. These findings highlight the potential of identified resistant genes in rice landraces for developing durable resistant varieties against N. lugens .

Rice blast, caused by Magnaporthe oryzae , is one of the most devastating diseases affecting rice crops. We investigated effectiveness of Streptomyces spp. against M. oryzae . The results revealed that among the Streptomyces spp., Streptomyces caeruleatus strain S14 demonstrated superior effectiveness in inhibiting the mycelial growth of M. oryzae (74.7%). The strain was identified by sequencing 16S rRNA region. Further, the complete genome sequence of this highly effective strain was acquired using the Illumina NovaSeq 6000 (PE 150), revealing a total genome length of 9,750,804 base pairs (9.7 Mb). The genome comprises 9,191 protein-coding sequences (CDS), 68 transfer RNA (tRNA) genes, 6 ribosomal RNA (rRNA) genes, with an average G+C content of 71.03%. The Streptomyces caeruleatus S14 genome, annotated with RASTtk and genetic code 11, falls under the superkingdom Bacteria. According to annotation statistics from PATRIC, it is a high-quality genome with 97.9% coarse consistency, 93.7% fine consistency, and completeness of 99.9%. The genome included genes related to metabolism, protein processing, defense, virulence, energy, stress response, membrane transport, regulation, cell signaling, cell envelope, DNA processing, cellular activities, RNA processing, and miscellaneous. The complete genome sequence of S. caeruleatus suggests that it offers valuable insights into its antimicrobial activity and provide key genetic traits responsible for pathogen suppression. Incidentally this is the first whole genome sequencing report of S. caeruleatus isolated from rice rhizosphere soil in India.

Rice-based integrated farming system improves the productivity and profitability by recycling resources efficiently. In the sub-humid tropics, rice production without sufficient nutrient replenishment often leads to soil health and fertility degradation. There has been very limited research on soil health and fertility after adopting a multi-enterprising rice-based integrated farming system (IFS), notably in the rice-fish-livestock and agroforestry system, when compared to a conventional farming system (CS). Therefore, the present study analyzed the dynamics of soil properties, soil bacterial community structure and their possible interaction mechanisms, as well as their effect on regulating soil quality and production in IFS, IFSw (water stagnant area of IFS) and CS. The results indicated that soil nutrient dynamics, bacterial diversity indices (Shannon index, Simpson index, Chao 1, ACE and Fisher index) and system productivity were higher in IFSw and IFS compared to CS. Moreover, relative operational taxonomic units of dominant bacterial genera ( Chloroflexi, Acidobacteria, Verrucomicrobia, Planctomycetes, Cyanobacteria, Crenarchaeota and Gemmatimonadetes ) were also higher in IFSw and IFS compared to CS. Mean soil quality index (SQI) was highest in IFSw (0.780 ± 0.201) followed by IFS (0.770 ± 0.080) and CS (0.595 ± 0.244). Moreover, rice equivalent yields (REY) and rice yields were well correlated with the higher levels of soil biological indices (SQI Biol ) in IFS. Overall, our results revealed that rice-based IFS improved the soil health and fertility and ensuing crop productivity through positive interaction with soil bacterial communities and nutrient stoichiometry leading to agroecosystem sustainability.

Land use and land cover (LULC) change have considerable influence on ecosystem services. Assessing change in ecosystem services due to LULC change at different spatial and temporal scales will help to identify suitable management practices for sustaining ecosystem productivity and maintaining the ecological balance. The objective of this study was to investigate variations in ecosystem services in response to LULC change over 27 years in four agro-climatic zones (ACZ) of eastern India using satellite imagery for the year 1989, 1996, 2005, 2011 (Landsat TM) and 2016 (Landsat 8 OLI). The satellite images were classified into six LULC classes, agriculture land, forest, waterbody, wasteland, built-up, and mining area. During the study period (1989 to 2016), forest cover reduced by 5.2%, 13.7%, and 3.6% in Sambalpur, Keonjhar, and Kandhamal districts of Odisha, respectively. In Balasore, agricultural land reduced by 17.2% due to its conversion to built-up land. The value of ecosystem services per unit area followed the order of waterbodies > agricultural land > forests. A different set of indicators, e.g., by explicitly including diversity, could change the rank between these land uses, so the temporal trends within a land use are more important than the absolute values. Total ecosystem services increased by US$ 1296.4 × 10 5 (50.74%), US$ 1100.7 × 10 5 (98.52%), US$ 1867 × 10 5 (61.64%), and US$ 1242.6 × 10 5 (46.13%) for Sambalpur, Balasore, Kandhamal, and Keonjhar, respectively.

Predicting Soil Organic Carbon (SOC) accurately and generating SOC distribution map holds potential for assisting farmers in assessing soil fertility, optimizing and enhancing the resource use efficiency. This study used Mica Sense Red Edge sensor mounted onboard Idea forge Q4c Unmanned Aerial System (UAS) to assess the distribution of SOC in the experimental site. Random Forest (RF) and Support Vector Machine (SVM) techniques were developed with both UAS as well as Sentinel datasets for SOC prediction. Overall, the UAS dataset exhibited greater accuracy in prediction of SOC compared to Sentinel Datasets. Random forest model provided an accurate prediction of SOC when used with the UAS dataset (RPD = 1.09, R 2 CV = 0.25, RPIQ = 2.57 and RMSECV = 0.06), whereas the Sentinel 2A dataset provided a better prediction of SOC with SVM model (RPD = 0.96, R 2 CV = 0.10, RPIQ = 0.96 and RMSECV = 0.07). The prediction map of SOC was generated using the UAS dataset with the RF model because it was found to be more accurate compared to the Sentinel and SVM model. The accuracy assessment indicators indicated that UAS based SOC prediction is having the potential in achieving more accurate predictions of SOC, which will offer an optimized agricultural practice and insights for supporting informed decision-making.

An experiment was conducted at Research Farm, National Rice Research Institute, Cuttack, Odisha, India to quantify the effect of elevated carbon dioxide (CO2) concentrations on the biology and morphometric parameters of yellow stem borer (Scirpophaga incertulas, Pyralidae, Lepidoptera). Yellow stem borer is one of the major pest of rice in the whole rice growing regions of South East Asia. The effect of three carbon dioxide concentrations i.e. 410 ppm (ambient), 550 ppm and 700 ppm on the duration of the developmental period as well as morphometric parameters of each stage of the lifecycle of the pest was analysed. It was found that, there was an increase in the duration of the developmental period of each stage of life cycle as the concentration of CO2 increases. However, the life span of the adult moth was significantly lower under the elevated CO2 concentrations when compared with ambient CO2 concentration. Morphometric parameters viz., mean length, width and weight of each larval instar, pupa and adult were found to be significantly higher in elevated concentrations of CO2 as compared to ambient concentration.

BackgroundRice is a major cereal crop and staple food of eastern India, and most farmers depend solely on rice for their livelihood. Rice farming provides both tangible and non-tangible benefits to ecosystems which need to be maintained and enhanced. These benefits are provided through ecosystem services (ES) that include both marketable and non-marketable.MethodsIn this study, the rice farms in eastern India were valued by quantifying the economic value of the services under conventional method of rice cultivation and the gap of ecosystem services value and farm income per unit area were assessed. A stratified random sampling technique was used in this study for selection of agro-climatic zones, districts, blocks, gram panchayat, and study units (households). Soil sampling was also performed for assessing the regulating services (biocontrol of pests, carbon flow, soil erosion, nitrogen fixation), provisioning services (food and by-products), and supporting services (soil fertility, hydrological flow, nutrient cycling, and soil formation).ResultsThe results indicated that the total economic value of ecosystem services ranged from US$ 1238 to 1688 ha−1 year−1. The marketed (primary production) and non-marketed ecosystem services values ranged from 66–89 to 11–34% of the total, respectively. Valuation of some of the ecosystem services such as cultural services, biodiversity, and gas regulation, which may play a significant role in total ecosystem services, has not been made due to non-availability of data and appropriate methodology for rice ecosystem. Different values of parameters can explain the variability in ecosystem services among the agro-climatic zones in eastern India. Clustering of locations based on variability of ecosystem services helps in identifying intervention points for sustaining and improving ecosystem services, while permitting sustainable agro-ecological intensification. The highest total economic gap between ES value and farm income was found in the north central plateau zone (US$ 1063 ha−1 year−1) and the lowest in the north western plateau zone (US$ 670 ha−1 year−1).ConclusionWe suggest various measures to reduce the economic gap, including payments for ecosystem services for rice farming for sustainability of the ecosystem and agricultural development, while ensuring reliable farm income.

The taxonomy of Azolla-cyanobiont is a long-term debate within the scientific community. Morphological and biochemicalbased reports indicated the presence of Anabaena, Nostoc and/or Trichormus azollae as abundant Azolla-cyanobionts, however, molecular data did not support the abundance of Anabaena and/or Nostoc. To understand furthermore, the cyanobiont diversity in six species of Azolla (A. microphylla, A. mexicana, A. filiculoides, A. caroliniana, A. pinnata and A. rubra) was analyzed based on 16S rRNA Illumina-MiSeq sequencing. Additionally, biomass and nutrient profiling of Azolla spp. were analyzed and correlated with cyanobiont diversity. Illumina-MiSeq data revealed that 99.6–99.9% of total operational taxonomic units (OTUs) belonged to Nostocophycideae (class), Nostocales (order) and Nostacaceae (family). At genus level, the unassigned affiliation (93.4–97.9%) under Nostacaceae family was abundant followed by Cylindrospermopsis OTUs (1.1–6.0%). Interestingly, A. pinnata harboured maximum Cylindrospermopsis OTUs and also recorded higher biomass (40.67 g m⁻² day⁻¹), whereas crude protein (25.9%) and antioxidants (76.9%) were recorded to be higher in A. microphylla. Biplot analysis revealed that A. pinnata and its cyanobiont abundance were positively correlated with neutral and acid detergent fibers. Overall, the present findings deepened the understanding about cyanobiont in Azolla and its relations with Azolla nutrient profiling.

Bakanae, caused by a fungal pathogen Fusarium fujikuroi is a major burden in rice cultivation. Management of this disease is crucial as it has the risk of being associated with the seed while exporting. Regular application of fungicides promotes the development of resistance to the molecule, and the lack of newer compounds paved the way for alternative management strategies. Salicylic acid (SA) and potassium silicate (PS) have gained momentum recently for their beneficial effects in promoting plant growth and controlling disease. Potassium silicate and salicylic acid are known to play a key role in enhancing plant defense. The present study investigates the individual and combined effect of PS and SA seed priming for plant growth and defense responses against Fusarium fujikuroi . The seed priming combined with SA (100 mg/L) and PS (1.0%) effectively controlled the bakanae disease incidence. In addition, it was also effective on growth parameters like improved germination, root and shoot length, plant biomass, and seedling vigor. Accumulation of defense enzymes like phenylalanine ammonialyase (PAL), polyphenol oxidase (PPO), Peroxidase (POD), and phenol derivatives was significantly higher in the treated plants. The maximum activity of these defense enzymes was recorded in PS+SA-treated plants at 21 DAS. The plant treated with SA-100 mg/L+ PS-1% showed the best response without any phytotoxic effect. The information gathered in the present study suggests that seed priming of SA-100 mg/L+ PS-1% can promote plant growth and suppress bakanae disease in rice. This research demonstrates how PS and SA can be used to combat the F. fujikuroi in rice by activating key defense enzymes. Additionally, applying these substances to plants stimulates their antioxidant defences, which indirectly prevents the spread of disease. In place of fungicides, the PS and SA treatment options are harmless for the environment and can be used to manage the bakanae disease. Future studies may be initiated to identify potential mechanisms behind the combined effects of SA and PS on plant growth promotion and disease suppression.