Rice Varieties Research Articles

The economic benefits, energy use efficiency, and carbon footprint of fragrant super rice and nonfragrant super rice under different planting methods and nitrogen levels.

The objective of this study was to investigate the input and output of energy, carbon input and sequestration, and economic benefits of fragrant and nonfragrant rice under different crop management practices, with the aim of providing theoretical guidance for sustainable rice production. Two high-yield and popular rice varieties, Yuxiangyouzhan and Jiyou615, were grown under three nitrogen fertilizer levels (0, 150, and 220 kg ha-1) and three planting methods (manual transplanting, mechanical transplanting, and mechanical direct seeding) during 2018 and 2019. The results showed that the economic, energy, and carbon benefits of the different rice varieties varied in response to the different fertilizations and planting methods. The average energy outputs of Yuxiangyouzhan and Jiyou615 were 214 423.26 and 218 474.90 MJ ha-1, respectively. The mean harvest index and mean energy use efficiency of Jiyou615 were slightly greater, at 4.21% and 3.93%, respectively, than those of Yuxiangyouzhan, while the mean carbon input-sequestration ratio of Yuxiangyouzhan was slightly greater, at 1.79%, than that of Jiyou615. Yuxiangyouzhan had a significantly greater mean benefit-cost ratio (5.76%) than Jiyou615. In addition, Yuxiangyouzhan had a significantly greater mean nominal economic return on energy input (12.21%), nominal economic return on energy output (13.20%), nominal economic return on carbon input (12.65%), and nominal economic return on carbon sequestration (11.31%) than Jiyou615. The results suggest that suitable high-yield and high-quality varieties with better consumer demand and the synergistic effect of variety and crop management in sustainable rice production are highly meaningful. © 2025 Society of Chemical Industry.

Molecular characterization of rice blast fungus (Pyricularia oryzae) from West Sumatra and their virulence to several rice cultivars

Global rice production is severely impacted by rice blast disease, which is a devastating condition caused by the fungal pathogen Pyricularia oryzae. Many countries have reported blast diseases associated with rice yield loss. In Indonesia, this disease also destroys rice production in several rice fields in West Java, East Java, Central Java, Sumatra, and Sulawesi. The objectives of this study were to identify rice blast fungal isolates in West Sumatra and assess the resistance level of eight local and modern rice genotypes to this disease. Additionally, the rice genotypes were also evaluated for the presence of Pi genes associated with blast resistance by utilizing 25 simple sequence-repeats (SSR) markers known to be linked to rice blasts. The seedlings of all rice genotypes were exposed to fungal isolates to determine their blast resistance capacity based on leaf morphological traits. Before conducting blast resistance testing, the local isolates of rice blast fungus were molecularly identified by aligning sequences in a pairwise comparison. Based on the identification process, three P. oryzae (MoK19-49, MoK19-45, and MoK19-28) fungal isolates were identified. The confirmed P. oryzae isolate MoK19-28 was then used to assess the blast resistance of the rice genotypes using the SES-blast test. The resistance levels of all genotypes were evaluated by observing the morphology of infected leaves for 24 days. Four genotypes, namely Cantik Manis (CM), Bungo Sungkai (BS), Inpari 48 Blas (IB), and Inpago 9 (Ip9), exhibited resistance to leaf blast caused by P. oryzae isolate MoK19-28. Meanwhile, Pulau Batu (PB), Mundam Putiah (MP), and IR64-Sub1 (IR) displayed intermediate resistance to the disease. In contrast, the blast fungus P. oryzae isolate MoK19-28 severely impacted the Kuriak (K) genotype. The rice variety IB contains several Pi genes, specifically Pi1, Pi9, Pikh, and Pi37, which are associated with enhanced resistance to leaf blast caused by P. oryzae isolate MoK19-28. This genetic characteristic sets it apart from susceptible genotypes. This work has successfully identified multiple blast-resistant rice genotypes that could potentially be used in future rice improvement initiatives.

Impact of incorporating wheat straw together with basal nitrogen ratio on panicle formation and grain yield in rice

Increasing spikelets differentiation, reducing their degradation and promoting big panicle formation are crucial approaches to increasing grain yield in rice. Straw incorporation and nitrogen (N) application have vital effects on rice yield, but the influence of incorporating wheat straw with N fertilizer ratio on spikelet differentiation, degeneration, and grain yield in rice is not clear. In this experiment, hybrid rice Fengyouxiangzhan (FY) and Yongyou 2640 (YY) were used as materials. Under the condition of total nitrogen application rate of 270 kg ha− 2, the effects of local farmers’ fertilizer practice (FP, basal fertilizer: tillering fertilizer: panicle fertilizer = 5: 1: 4) and improving basal fertilizer proportion (IP, basal fertilizer: tillering fertilizer: panicle fertilizer = 7: 1: 2) on the grain yield, branch and spikelet differentiation and degeneration of the above rice varieties were studied under the conditions of non-wheat straw returning (NR) and wheat straw full returning (WR). The 2-year (2020–2021) results in field trials showed that: (1) under NR, compared with FP, although the panicles per unit area were increased, the spikelet number per panicle, filled grains, and grain weight decreased to varying degrees, and finally the grain yield decreased significantly in IP. Under WR, although the filled grains and grain weight were decreased in IP treatment, the total spikelets (panicles per unit area × spikelet number per panicle) was increased significantly, and the grain yield was finally increased significantly compared with FP, with an increase of 6.85 ~ 7.08%. (2) There was a strong positive link between the total spikelets and grain yield, but a substantial negative relationship between the total spikelets and the number of filled grains and grain weight. (3) Straw treatment and nitrogen treatment mainly affected the spikelet number per panicle by affecting the differentiation and degeneration of secondary branches and spikelets. Under WR, IP increased the differentiation number of secondary spikelet in the middle and basal parts of FY by 22.0% and 30.9% with FP, respectively, but also increased the number and rate of secondary spikelet degeneration in the middle and basal parts. Under IP, compared with NR treatment, the differentiated number, degenerated number, surviving number, and degradation rate of the middle and basal parts of the secondary spikelets in the two varieties were increased in WR treatment. Overall, these results demonstrated that under WR, IP was beneficial to increase effective panicle numbers and the spikelet number per panicle. More secondary spikelet differentiation in the middle and basal parts per panicle was a main reason for increasing the spikelet number per panicle to increase grain yield under IP treatment.

The near-optimal adjustment of carbon and nitrogen allocations into different organs in early-season rice cultivars with drastically different yield components under nitrogen application

IntroductionOptimized photosynthesis and transport of photosynthate from the upper three leaves in a rice plant is critical for yield formation in rice.MethodsIn this study, we selected two high-yielding early-season rice cultivars, i.e. a large-panicle inbred rice Zhongzao39 (ZZ39) and a plural-panicle hybrid rice Lingliangyou268 (LLY268) with high effective panicle number, to study the translocation of photosynthate from the flag and the basipetal 2nd leaves to the other organs under different nitrogen application scenarios. 13CO2 labeling was study the proportion of newly assimilated carbon partitioned into different organs.ResultsResults demonstrate that the ratio that 13C assimilated in the flag leaves and the basipetal 2nd leaves, and the distribution ratio 13C in the organs of ZZ39 and LLY268 cultivars were not affected by nitrogen application. However, at the booting stage, the translocation rate of photosynthate was slower under N150 compared with CK in both flag and the basipetal 2nd leaves labeled with 13C. At the grain filling stage, an average of 51% of photosynthetic products labeled with 13C was translocated to the panicle in both cultivars under CK treatment; in contrast, only 43% of leaf photosynthate was translocated to panicles in the N150 treatment. At maturity, the photosynthate labeled with 13C distribution ratio in the panicle was greater in the basipetal 2nd leaves than in the flag leaves for ZZ39, whereas the opposite was observed in LLY268. These different photosynthate allocation patterns and their responses to nitrogen application were linked with their corresponding tiller number and number of grains per panicle.DiscussionThis study shows that early-season rice has the ability to flexibly adapt their carbon and nitrogen allocation patterns to gain optimized yield components for higher yield under different nitrogen status. Early season rice can be used as a model system to study the growth strategy selection of plants to changing environment conditions.

Improvement of Agronomic Parameters of Rice Plants Infected by Rice Yellow Mottle Virus (RYMV) Using Plant Extracts

Aims: The aim of this study was to assess the effect of plant extracts Azadirachta indica, Piper nigrum L, Acacia gummifera, Combretum micranthum, and Clenodium vulgare L on rice yellow mottle virus in rice. Study Design: The experiment was conducted in a Randomized Complete Block Design (RCBD) with five repetitions. The blocking factor was the sunshine. Place and Duration of Study: The study was carried out at the Microbiology and Microbial Biotechnology Research Laboratory (LaboREM-Biotech) of the Faculty of Sciences and Techniques, between June and November 2020. Methodology: The rice variety Kogoni91-1, which is highly susceptible to rice yellow mottle, was grown under greenhouse at the LaboREM-Biotech, inoculated with a highly virulent virus from the laboratory's collection and treated with plant extracts. Results: The results showed that rice plants treated with the combination of plant extracts from C. micranthum, A. indica, and C. vulgare recorded higher grain and aerial biomass yields than the positive control and very close to those of the negative control. Similarly, plants treated with black pepper extracts showed a number of spikelets, a yield and an aerial biomass higher than those of the positive control and very close to those of the negative control. Conclusion: Using plant extracts to combat rice yellow mottle could be an alternative to the application of chemical pesticides harmful to human and animal health.

Effects of Selenium Foliar Spraying on Seedling Growth and Stem Sheath Hardness in Fragrant Rice

Previous studies have shown that selenium (Se) can influence rice growth and yield. However, the Se effect on rice lodging remains unknown. This study aimed to investigate the impact of different Se treatments on seedling growth and stem sheath hardness in fragrant rice. A hydroponic experiment was conducted using two fragrant rice varieties, Yuxiangyouzhan and Xiangyaxiangzhan, as experimental materials. Two forms of selenium fertilizers (amino acid-chelated selenium and sodium selenite) were used. There were five foliar spraying selenium fertilizer treatments (CK: no selenium fertilizer; T1: 4 μmol·L−1 amino acid-chelated selenium; T2: 8 μmol·L−1 amino acid-chelated selenium; T3: 4 μmol·L−1 sodium selenite; and T4: 8 μmol·L−1 sodium selenite), and the effects of the different selenium fertilizer treatments on seedling growth and stem sheath hardness in fragrant rice were studied. Significant Se treatment effects on root fresh weight, seedling dry weight, plant height, stem sheath length, number of leaves, chlorophyll content, stem sheath hardness, peroxidase activity in leaf and stem sheaths, and lignin content in the roots were detected. A significant Se treatment and variety interaction effect on the stem sheath hardness was observed. The different forms/levels of selenium fertilizer affected the seedling growth and the stem sheath hardness differed. The Se treatments improved seedling growth and significantly affected the dry weight, chlorophyll content, stem sheath hardness, and peroxidase activity in leaf and stem sheaths. Compared with the CK treatment, the Se treatments increased the total dry weight of seedlings in Xiangyaxiangzhan and Yuxiangyouzhan by the ranges of 25.43–52.77% and 18.97–30.09%, respectively. The T2–T4 treatments increased the stem sheath hardness values in Xiangyaxiangzhan and Yuxiangyouzhan by the ranges of 21.6–54.7% and 38.3–146.6%, respectively, as compared to the CK treatment. The Se treatments had a promoting effect on physiological indexes such as stem sheath length, lignin content in the stem sheath, and dry matter accumulation in different plant tissues, thereby increasing the total dry weight. The Se treatment had an inhibitory effect on chlorophyll b content and total chlorophyll content, whilst it increased the chlorophyll a content and chlorophyll a/b ratio, which in turn affected the photosynthesis of rice. Therefore, appropriate Se treatments (the application of 8 μmol·L−1 amino acid-chelated selenium, 4 μmol·L−1 sodium selenite, and 8 μmol·L−1 sodium selenite) could improve seedling growth and stem sheath hardness, which was related to the parameter changes, such as the dry weight, photosynthesis pigments, and peroxidase activity. These findings suggest that different Se fertilizers can positively regulate rice resistance to lodging and growth. This study can provide theoretical support for the application of selenium fertilizer.

Different harvesting dates influence the growth, seed yield and quality of two rice varieties in Ghana

Rice (Oryza sativa L.) is a staple food which contains a high amount of nutrients essential for human nutrition, energy supply, and food security. Despite its nutritional value, it does not reach its physiological maturity at the same time thereby affecting the quality of seeds produced when harvested. The overarching objective of this research was to determine the influence of harvesting days on seed yield and quality of two rice varieties (Jasmine 85 and Amankwatia) at the Department of Horticulture, Kwame Nkrumah University of Science and Technology, Ghana. A 2 x 3 factorial arranged in a Randomized Complete Block Design with three replications was the study design. Factor one was the two varieties (Jasmine and Amankwatia) and factors two was different harvesting times at three levels [105, 112 and 126 days after transplanting (DAT)]. The study revealed that Jasmine 85 had the highest plant height, number of panicles and number of tillers. The study also showed that the interaction of the varieties and different harvesting times had a significant influence on the germination percentage, germination energy, germination rate index and mean germination time. The study showed that Amankwatia harvested at 126 DAT and Jasmine harvested at 112 DAT respectively, performed the best in terms of yield. Furthermore, Amankwatia harvested at 112 DAT and Jasmine harvested at 105 DAT respectively, also improved germination parameters. Harvesting of both varieties (Jasmine and Amankwatia) at 112 DAT and 126 DAT will maximize yield, while harvesting at Amankwatia at 112 DAT and Jasmine at 105 will improve germination. Int. J. Agril. Res. Innov. Tech. 14(2): 122-131, December 2024

Unravelling Candidate Genes Associated With Blast Disease Resistance in an Elite Green Super Rice Varietal Panel Using Genome‐Wide Association Study

ABSTRACTRice blast disease, caused by the filamentous fungus Magnaporthe oryzae, significantly threatens global rice crops leading to yield losses worldwide. Given that existing resistance genes often fail to control rice blast due to the evolution of new virulent strains, identifying novel genes using modern breeding tools to enhance partial resistance is crucial for developing more durable and effective control measures. Here, we used a genome‐wide association study (GWAS) with 2698 high‐throughput single‐nucleotide polymorphism (SNP) markers to analyse 134 rice cultivars from the Green Super Rice breeding programme against two virulent rice blast isolates, M101‐1‐2‐9‐1 (M101) and M64‐1‐3‐9‐1 (M64). GWAS identified 12 potential quantitative trait loci (QTLs) for blast resistance: five against M101 on chromosomes 1, 2, 3, 4 and 7 and seven against M64 on chromosomes 1, 4, 5, 6 and 12, with no QTL in common against both. Notably, qM101_2 is within the 500 kb linkage disequilibrium (LD) block containing the known resistance gene Pib on chromosome 2, and qM64_12.1 and qM64_12.2 are within the Pi‐ta and Ptr gene cluster on chromosome 12. The remaining nine QTLs represented novel blast disease resistance sources. The identified candidate genes, including those encoding nucleotide‐binding site leucine‐rich repeats domains, protein kinases, resistance gene analogues and pathogenesis‐related proteins, may serve as a foundation for further studies to explore their potential role in enhancing disease resistance in rice.

Integrating phenotypic and molecular profiling for selection of promising advanced breeding lines for blast resistance in rice (Oryza sativa L.).

Rice is susceptible to several major and minor diseases, with blast disease caused by Magnaporthe oryzae being a significant constraint, leading to substantial economic losses worldwide. Exploiting genetic resistance in cultivars is a preferred strategy for managing this disease, offering an alternative to chemical control. The objective of this study was to identify advanced breeding lines (ABLs) with blast resistance, superior yield, and good grain quality using Marker-Assisted Selection (MAS). Leaf blast resistance screening revealed that 25 ABLs exhibited moderate resistance. Molecular analysis with 10 polymorphic markers linked to blast resistance genes (Pi1, Pi2, Pi9, Pi37, Pi38, Pi39, Pi54, Pita, Pitp, and Piz5) identified the highest number of positive alleles (8) in MTU1061, IR36, and SVGP-26. Additionally, seven ABLs (SVGP-1, SVGP-14, SVGP-23, SVGP-37, SVGP-38, SVGP-39, and SVGP-48) showed co-segregation of markers with blast resistance. Genetic diversity analysis revealed significant variability among the genotypes, indicating diverse genetic backgrounds. Based on their yield performance, quality traits, and resistance to blast, five parents (NLR 34449, NLR 40024, MTU 1061, MTU 3626, and IR 36) and five ABLs (SVGP-13, SVGP-16, SVGP-40, SVGP-47, and SVGP-32) were selected for further yield trials. The study identified high-yielding, blast-resistant lines with good grain quality and diverse genetic backgrounds as promising donor sources for improving blast resistance in rice breeding programs. These findings enhance the genetic base for developing resistant rice cultivars with improved agronomic traits.

Grain Weight and Taste Quality in Japonica Rice Are Regulated by Starch Synthesis and Grain Filling Under Nitrogen–Phosphorus Interactions

To reveal the regulatory effects of nitrogen and phosphorus interactions on grain-filling- and starch-synthesis-related enzymes, and grain weight of superior grains (SGs) and inferior grains (IGs) and taste quality, the japonica rice cultivar Shennong 265 was grown under field conditions with three nitrogen levels (210, 178.5, and 147 kg N ha−1; N3, N2, and N1) and two phosphorus levels (105 and 73.5 kg P ha−1; P2 and P1). At the N3 level, the yield of P1 was significantly lower (by 19.26%) compared to P2; at the N2 and N1 levels, P1 yielded higher than P2, peaking at N2P1. Spikelets per panicle showed P2 exceeding P1 at the same nitrogen level, with the highest for both SGs and IGs observed at N2P2, followed by N2P1. Reductions in nitrogen and phosphorus decreased the grain-filling rate but prolonged the duration for grain-filling. N2P1 maintained grain weight by extending the grain-filling duration across the early, middle, and late stages of IGs, and the middle and late stages of SGs. Increased nitrogen enhanced the activities of soluble starch synthase (SSS) and starch branching enzyme (SBE), whereas increased phosphorus inhibited these activities in SGs but enhanced them in IGs. Reduced nitrogen and phosphorus fertilizer diminished ADP glucose pyrophosphorylase (AGPP) and granule-bound starch synthase (GBSS) activities in SGs and IGs, inhibiting amylose accumulation while enhancing taste value. Compared with N3P2, the taste value of N2P1 increased significantly by 6.93%, attributed to a higher amylopectin/amylose ratio. N2P1 (178.5 kg N ha−1 and 73.5 kg P ha−1) optimized enzyme activity, starch composition, and grain filling, balancing both yield and taste, and thus demonstrated an effective fertilization strategy for stable rice production.

Identification of Quantitative Trait Loci and Development of Intermediate Breeding Parent for Rice Sheath Blight Resistance

The soil-borne pathogen <i>Rhizoctonia solani</i> is one of the most devastating necrotrophic pathogens worldwide, responsible for causing rice sheath blight (RSB). This pathogen has a broad host range, affecting economically important monocots and dicots such as rice, wheat, potato, soybean, sugar beet, and cucumber. Despite extensive screening of rice germplasm, genes that confer full resistance to RSB have rarely been identified, leading to slow progress in breeding resistant varieties. To identify RSB-resistant rice cultivars in Korea, variations in quantitatively inherited resistance have been observed. We conducted a study to visually assess the RSB resistance phenotypes of 250 cultivated varieties under natural disease conditions in the field over several years. Notable candidates included P1401, which showed resistance, while Junam was susceptible. To identify the quantitative trait loci (QTLs) associated with resistance, we developed an F2 mapping population by crossing P1401 and Junam, followed by bulked segregant analysis. These QTLs were mapped to specific locations on seven of the 12 rice chromosomes. This mapping population and the resulting datasets provide valuable resources for advancing genomic research in rice, particularly for marker-assisted breeding strategies for enhancing resistance to <i>R. solani</i> and other important agronomic traits.

High-Throughput Screening of Plant Extracts for Targeted Control of Burkholderia glumae, Causing Rice Sheath and Panicle Blight

Rice (<i>Oryza sativa</i>), a staple crop worldwide, is severely threatened by bacterial panicle blight caused by <i>Burkholderia glumae</i>, leading to substantial yield losses. The lack of effective chemical treatments and resistant rice cultivars highlights the urgent need for alternative solutions. In this study, 1,134 plant extracts were screened for antibacterial activity against <i>B. glumae</i> using agar disc diffusion and liquid broth assays. Thirty-three extracts exhibited significant growth inhibition on agar plates. These 33 extracts were further tested in Luria- Bertani broth, where five showed notable activity, and two extracts—<i>Trapa japonica</i> (FBCC-EP312) and <i>Rumex crispus</i> (FBCC-EP487)—were selected for detailed analysis. Both extracts significantly reduced bacterial motility and disease severity in rice, while having no effect on non-target bacteria such as <i>Escherichia coli</i>. These findings highlight the potential of these plant-derived compounds as effective biocontrol agents, offering an eco-friendly alternative to synthetic pesticides and promising applications in sustainable agriculture.

Mechanism harvesting of main crops straw returning effects on ratooning fragrant rice yield and 2-accetyl-1-pyrroline and their drivers to soil microbial communities

Straw return to the field is an important measure for increasing soil fertility to increase production. Recent studies have shown that straw return to fields can increase rice yield, but the effect of straw return to fields on ratooning rice is limited. To address this problem, this paper investigated the effect of straw return on a ratooning rice system by harvesting at different heights during the first season.A two-year field experiment was conducted by using a fragrant rice variety (Meixiangzhan 2) as the material. Three experimental treatments including i) the CK treatment: manual harvesting and straw harvested at a height of 20 cm was not returned to the field; ii) the MT1 treatment: mechanical harvesting and straw was returned to the field at a harvest height of 10 cm; iii) the MT2 treatment: mechanical harvesting and straw at a harvest height of 20 cm was returned to the field. The investigated parameters in the rice cropping system in this study were the agronomic traits, yield formation, soil properties, and root soil microorganisms.We found that compared with those in the CK treatment, the yield and 2AP content in the MT treatment significantly increased, the yields of MT1 and MT2 increased by 18.17-32.64% and 12.19-20.42%, respectively. The contents of available potassium, available phosphorus, ammonium nitrogen and active organic carbon in the soil were significantly increased by straw return to the field. The soil capacity increased, and rice production increased. In addition, the straw returned to the field produced a large amount of cellulose and anaerobic environment, which provided an explanation for the increase in some anaerobic bacteria, such as pseudxanthomonas, Rhodobacteriaceae and desulphurides in the MT treatment group. Specifically, straw return provides a large amount of organic material for rice cultivation systems and improves soil fertility under the action of microorganisms to increase production.Overall, the interaction between straw return and harvest height had different effects on yield and 2AP content, and the MT2 treatment was the most beneficial for harvesting ratooning fragrant rice.

Improvements in Tolerance to Heat Stress in Rice via Molecular Mechanisms and Rice Varieties

Global warming affects crop growth and development, threatening food security. As one of the essential food crops, rice is severely affected by high temperature stress, which compromises both its yield and quality. Therefore, gaining a deep understanding of the molecular mechanisms by which rice responds to heat stress and breeding rice varieties that are tolerant to such stress is crucial for maintaining food security. This review summarizes the impacts of heat stress on yield and quality-related traits at different growth and development stages of rice, the molecular mechanisms of rice perception and response to heat stress, and the improvement in and breeding of heat-tolerant rice varieties using existing superior alleles/QTLs. We also discuss the opportunities and challenges in creating highly heat-tolerant rice germplasm, providing new ideas and insights for the future breeding of heat-tolerant rice varieties.

Antioxidant Activity, Total Phenolic and Total Flavonoid Content of 22 Sabah Traditional Rice Varieties

Studies have demonstrated that the traditional rice cultivated in Sabah, East Malaysia, exhibits substantial genetic diversity and is renowned for its outstanding nutritional content. However, there are limited studies to ascertain the antioxidant activity and composition of biochemical substances in it. The present study evaluates the antioxidant properties of 22 Sabah Traditional Rice varieties, which are classified into pigmented and non-pigmented types. An analysis was performed on 22 Sabah Traditional Rice varieties to determine their Total Phenolic Content (TPC), Total Flavonoid Content (TFC), and DPPH assay. In addition, a metabolic profiling analysis was performed on biochemical substances extracted from a specific rice variety, Beras Perang, which is known for its high levels of TPC, TFC, and antioxidant activity. It was observed that pigmented rice possesses high phenolic content, namely Beras Perang and Baragang Merah (semi-polished), with values ranging from 1.300±0.004 to 1.967±0.019 mg GAE/g. For TFC results, Beras Perang, Masuri Hitam and Tadong Biasa (unpolished) showed higher abundance (1.000±0.001, 0.888±0.001 and 0.793±0.003 mg QE/g), respectively. The antioxidant assay results indicate that three varieties, namely Baragang Merah (92.832± 0.651%), Beras Perang (91.916± 0.331%), and Rongguol (91.965± 0.515%) have antioxidant levels exceeding 90%. Beras Perang has the greatest levels of TPC, TFC, and antioxidants. In metabolic profile analysis, Beras Perang contains a specific form of linoleic acid (12-oxo-10Z-octadecenoic acid) which is not present in the negative control. In conclusion, Sabah Traditional Rice exhibits a highly promising antioxidant activity, over 90%, making it a potential candidate for further development as an alternative superfood.

Assessment of Genetic Diversity of Rice (Oryza sativa (L.) Genotypes under Aerobic Condition

The present study was carried out at Anbil Dharmalingam Agricultural College and Research Institute, Trichy under aerobic conditions. The experimental material comprised forty-nine rice genotypes, which were laid out in randomized complete block design with two replications. The data on ten quantitative characters were recorded to assess the magnitude of genetic diversity through D2 analysis. Based on genetic distance, rice genotypes were grouped into five clusters. Among the five clusters, cluster I had the highest number of genotypes (42) and cluster V had the lowest number of one genotype. The range of inter-cluster distance was 65.33 (between clusters IV and V) to 7.91 (between clusters II and III). The genotypes in cluster IV and cluster V exhibited a high degree of genetic diversity due to the maximum inter-cluster distance between them, and these genotypes may be utilized under a hybridization program for getting high-yielding and desirable recombinants.

Evaluating the yield potential of the mutant (M6) short stem of mentik wangi rice varieties developed through 200-gray gamma irradiation

Evaluating the yield potential of the mutant (M6) short stem of mentik wangi rice varieties developed through 200-gray gamma irradiation

Uncovering microbial drivers and regulatory edaphic factors for DNRA-nitrogen recovery under diverse rice agro-ecosystems

Uncovering microbial drivers and regulatory edaphic factors for DNRA-nitrogen recovery under diverse rice agro-ecosystems

Isolation and characterization of plant growth promoting actinobacteria, Amycolatopsis samaneae (AM75), from the rice rhizosphere in mirza area, Assam, India

This study aimed to isolate plant growth-promoting actinobacteria from the rhizosphere of rice. Rhizospheric soil samples were collected from the Aijung variety of rice in the Mirza area, Kamrup district, Assam, India. The isolate AM75 identified as Amycolatopsis samaneae, was characterized as gram-positive and non-motile. It exhibited varied colony characteristics on different selective media. The isolate produce several enzymes including urease, nitrate reductase, lipase, catalase, and amylase but did not demonstrate cellulase or gelatinase activity. Notably, isolate AM75 displayed various plant growth-promoting activities such as siderophore activity, hydrogen cyanide (HCN) production, indole-3-acetic acid (IAA) production, and zinc solubilization. However, it did not produce hydrogen sulfide (H2S) or solubilize phosphate. The optimal growth conditions for AM75 were pH 7.2, 30ºC temperature, and NaCl 2.5% concentration. Additionally, AM75 exhibited inhibitory activity against the plant pathogens Erwinia chrysanthemi ATCC11660, Aspergillus niger ATCC6275, and Fusarium oxysporum ATCC62506. The isolate was resistant to standard antibiotics, including rifampcin, streptomycin, ampicillin, and nalidixic acid.

GloRice, a global rice database (v1.0): I. Gridded paddy rice annual distribution from 1961 to 2021

Paddy rice, one of the world’s primary cereals, plays a critical role in food security and environmental sustainability. Existing global rice distribution datasets provide valuable insights but are often constrained by time and coverage. In this study, we developed the GloRice (I), a long-term global gridded dataset mapping rice harvested and physical areas at a 5-arcminute resolution for 1961–2021. The dataset consists of three components: (1) GloRice-2000hvst: four types of rice harvested area maps for the year 2000, using multiple established datasets (M3, SPAM, GAEZ); (2) GloRice-hvst: annual harvested area maps (1961–2021) integrating national and subnational statistics; and (3) GloRice-phsc: annual physical area maps (1961–2021) derived from the rice multiple cropping index (MCI) data. Validation demonstrated strong agreement at global and regional levels, with consistent accuracy in subnational comparisons for major rice-producing regions, including China, South Asia, and Southeast Asia. The GloRice (I) provides essential data input for regional and global modelling and assessments, with broad applicability in agriculture, climate, and environmental research.