Rice Varieties Research Articles

Effect of Leaf Clipping and Nitrogen Split Application on Bridegroom Rice Productivity

Bridegroom rice is one the most important indigenous rice variety predominantly grown in Tamil Nadu, India. Lodging in nature and poor responsive to nitrogenous fertilizers affects the yield of this crop. To minimize crop lodging and to enhance the productivity, a field experiment was carried out during Samba 2023 at Experimental Farm, Department of Agronomy, Annamalai University, Tamil Nadu, India to study the effect of leaf clipping and nitrogen split application on bridegroom rice productivity. The experiment was laid out in Factorial randomized block design (FRBD) with three replications. The treatments consisted of two factors viz., Factor I -leaf clipping (L): L1- No leaf clipping, L2 - leaf clipping on 30 DAT at one third of leaf, L3- leaf clipping on 45 DAT at one third of leaf and Factor II - split application of N (N) : N1- no splits (no NPK), N2 - 4 equal splits (basal, 25, 50, 75 DAT), N3­- 5 equal splits (basal 20, 40, 60,80 DAT ) and N4 - 6 equal splits (basal, 15, 30, 45, 60 ,75 DAT). Among the treatments, leaf clipping on 45 DAT at one third of leaf along with application of nitrogen in 6 equal split registered its superiority compared to others which recorded the higher values for growth attributes viz., plant height (243cm), number of tillers hill-1 (23.42), root length (33.56cm), root volume (45.19 cc) and dry matter production (12592 kg ha-1),yield attributes viz., number of panicles m-2 (407.62) and number of grains panicle-1 (158.34) and test weight (42.34g) and yields of rice (grain - 3950 kg ha-1­and straw - 6530 kg ha-1­). Thus, it can be concluded that leaf clipping on 45 DAT at one third of leaf along application of nitrogen in 6 equal splits is a viable practice to enhance the growth and yield of bridegroom rice.

Optimization of phosphorus and potassium use efficiency of rice (Oryza sativa L) under different flood depths within the Everglades Agricultural Area

Rice cultivation in South Florida, especially within crop rotation systems, presents a promising avenue for mitigating phosphorus (P) levels in drainage water by optimizing nutrient absorption across varying flooding conditions. This study aimed to assess the impacts of different flooding depths on rice growth and nutrient efficiency while exploring the interrelationships among these factors. Conducted over a two-year period, the field study involved planting a single rice variety (Diamond: 95 kg ha−1, long-grain, short-season) at four distinct flooding depths (5, 10, 15, and 20 cm) without fertilizer application. Results revealed minimal effects of flooding depths on root and shoot length or dry matter accumulation. Additionally, concentrations of total P and potassium (K) in both shoot and root tissues remained consistent across the different flooding depths. Despite the absence of P and K fertilizer inputs, no significant changes were observed in P use efficiency (PUE), K use efficiency (KUE), or water use efficiency (WUE). Cultivating rice under optimal flood depths of 5 cm within the Everglades Agricultural Area (EAA) demonstrated potential for conserving water and essential nutrients such as P and K. These findings highlight the feasibility of rice cultivation in fertile soils as a means to decrease nutrient (P and K) concentrations in drainage water, thereby promoting sustainable agricultural practices in the region.

Transfer factors of naturally occurring radionuclides from soil-to-rice cultivated in Bangladesh and associated health implications

This study investigates the uptake of naturally occurring radionuclides (226Ra, 232Th, and 40K) from soil by rice plants in extensively cultivated regions in Bangladesh. It also evaluates the potential radiation risks associated with rice consumption by the Bangladeshi populace. High purity germanium (HPGe) gamma-ray spectrometry was employed to measure the concentrations of radionuclides in both soil and rice samples. For 40K, our results agree with the International Atomic Energy Agency's (IAEA) published value; however, the transfer factors (TF) for the other two radionuclides differ considerably. Despite the fact that the IAEA based its publication of TFs for 226Ra and 232Th on clay soil, the majority of the soil profile in the present study was silty clay with a little alkalinity. Moreover, the data obtained may have been impacted by the growing seasons, cultivation methods, and soil fertility. Additionally, the annual effective dose due to the ingestion of radioactivity resulting from rice consumption was evaluated and the results agree with UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation), 2000. With a few exceptions, the excess lifetime cancer risk (ELCR) values for 226Ra, 232Th, and 40K were below the globally average permissible level (1 × 10−3). In light of this, the current study indicates that consuming rice does not pose an immediate health risk to the general public. By studying TFs among various rice varieties and geographical areas, scientists can develop models to forecast the possible radiation exposure from rice consumption and pinpoint activities or areas that require additional attention.

Gene Editing for Disease Resistance in Crops: Success Stories and Challenges

Gene editing has emerged as a transformative tool in modern agriculture, offering new avenues for enhancing disease resistance in crops. By precisely modifying the DNA of plants, scientists can develop varieties that are better equipped to withstand the onslaught of pathogens, which pose significant threats to global food security. This article delves into the success stories and challenges associated with gene editing for disease resistance in crops, with a focus on technologies like CRISPR-Cas9, TALENs, and ZFNs. One of the major success stories in this field is the development of disease-resistant varieties of wheat, rice, and tomatoes. For instance, researchers have used CRISPR-Cas9 to create wheat varieties resistant to powdery mildew, a devastating fungal disease. Similarly, gene editing has enabled the development of rice strains with enhanced resistance to bacterial blight, a disease that can lead to significant yield losses. In tomatoes, gene editing has been employed to confer resistance against the Tomato Yellow Leaf Curl Virus, which severely affects tomato production worldwide. These achievements underscore the potential of gene editing to create crops that are not only more resilient but also capable of maintaining high yields under disease pressure. However, the application of gene editing in crop disease resistance is not without challenges. One of the primary concerns is the regulatory landscape, which varies significantly across different countries. While some nations have embraced gene-edited crops, others have imposed strict regulations, treating them similarly to genetically modified organisms (GMOs). This inconsistency can hinder the global deployment of disease-resistant crops and create trade barriers. Additionally, there are concerns related to off-target effects, where unintended changes in the genome may occur, potentially leading to unintended consequences in the plant's growth or ecological interactions.

Field Screening for Low Levels of Toxic Inorganic Arsenic in Dry-Season Rice Varieties from Bangladesh

Field Screening for Low Levels of Toxic Inorganic Arsenic in Dry-Season Rice Varieties from Bangladesh

Development of a Technology Valuation Model for Commercial Licensing: An Empirical Case of PB 1718 Basmati Rice Variety

Development of a Technology Valuation Model for Commercial Licensing: An Empirical Case of PB 1718 Basmati Rice Variety

Monitoring of Virulence of Gall Midge (Orseolia oryzae Wood-mason) Population on Rice

A study was conducted for two years during 2022 and 2023 at Regional Agricultural Research Station, Warangal, Telangana, India to know the virulence of gall midge on rice varieties with known gall midge resistant genes at Warangal. During both the years i.e., 2022 and 2023, the virulence of gall midge was low in Aganni followed by Akshayadhan, W1263 and Purple. The gall midge virulence was very low and similar in Aganni and Akshayadhan which reveals the efficacy of gall midge resistance genes i.e., Gm4 and Gm8 against gall midge biotype 4M at Warangal. Since Purple variety does not have any gall midge resistant genes, gall midge virulence was highest on Purple variety. The study revealed that, gall midge genes viz., Gm4 and Gm8 are holding good for resistance against gall midge biotype 4M in both the years of study. However, a close monitoring of the virulence pattern in endemic areas is important for deployment of effective genes in developing resistant varieties.

The Effect of Organic and Mineral Substances on the Productivity and Quality Indicators of Rice in Lankaran

The study of different rice varieties, determination of their compatibility with soil and climatic conditions is the most important direction in the development of agricultural science. In 2022, research work was carried out on three rice varieties in the village of Shikhakaran, Lankaran district: Govhar (regional), Sarykiprik (local) and Avangard (improved). Soil samples were collected and analyzed taking into account the introduction of various organic fertilizers, including nitrogen, phosphorus and potassium in five variants and three replicates. Phenological observations were carried out and the qualitative and quantitative indicators of plants were studied. According to the results obtained, it can be noted that rice growth varies from 109.3 to 148.0 cm, plant bushing is 6.7-15.5 cm. The highest bushing was noted against the background of mineral fertilizer in the Govhar variety. The length of the lateral shoots is at least 21.5 cm, maximum 25.2 cm. Accordingly, the number of grains on the lateral shoots is 56.0-109.4 pcs. On the lateral shoots, the highest indicator was observed in the Govhar variety — 2.0-5.2 g. The productivity of the Govhar variety against the background of mineral fertilizers was 25.5 g, and for the Avangard variety — 23.3 g. The thousand seed weight is 23.2-33.1 g, and the Govhar, Sarykiprik, Avangard varieties were distinguished by relatively high indicators against the background of mineral fertilizer. In grains, in terms of protein content, against the background of organic fertilizer, the Govhar variety was 9.03%, against the background without fertilizer, the Sarykiprik variety - 9.3%, against the background of organic and mineral fertilizer, the Avangard variety — 8.87%. No differences in the amount of sugar in seeds were found between the varieties.

Indica rice “Takanari” exhibited superiority to Japanese rice “Koshihikari” on N-uptake and biomass production under no-weeding practice

ABSTRACT Rice yield and whole biomass production are strongly related to the rice cultivar’s nitrogen (N) uptake ability and various meteorological conditions and management practices. Under different conditions, such as elevated CO2 with limited N-supply, the Indica cultivar” Takanari (Tak)” showed a higher N-uptake ability than the Japonica cultivar ‘Koshihikari (Kos).’ However, it is still unclear how Tak and Kos respond to N-uptake and biomass production under limited N conditions with or without weeding. For this reason, we conducted a pot experiment at Tsuruoka, Yamagata, Japan, in the 2022 rice growing season. Tak and Kos were transplanted individually and interplanted (Tak+Kos) in pots filled with 8.0 kg of air-dried alluvial soil from an organic rice farm with the main treatments of weeding and no weeding. Rice growth parameters (shoot height, tiller numbers, and leaf color) were investigated weekly, while rice biomass and N-uptake were measured after harvest. As a result, plant biomass and N-uptake were significantly different among all treatments. The rice biomass and N-uptake in weeding were significantly higher than those in no-weeding for both cultivars. Compared with Kos, Tak had significantly higher rice biomass and N-uptake for root, ear, and whole rice plants in all treatments, weeding practices, and planting modes. The ratios of aboveground biomass and N-uptake between Tak and Kos in interplanting were higher than their respective ratios in individual planting. Interplanting increased the aboveground biomass ratios between Tak and Kos by 16.24% and 27.43% in weeding and no-weeding conditions, respectively. The ratios of N-uptake in interplanting were higher than individual planting at 21.74% and 34.09% in weeding and no-weeding, respectively. Tak’s ability to compete with Kos on N-uptake and biomass production was increased when two rice cultivars were transplanted in the same pot under interplanting cultivation and no-weeding conditions.

Metabolomics combined with proteomics reveals phytotoxic effects of norfloxacin under drought stress on Oryza sativa

In recent decades, plants enduring abiotic stresses such as drought and chemical stresses. Currently, the mechanism of combined antibiotic and drought stress response and its impact on crop growth and food security remains poorly understood. Here, the mechanism of stress responses under the exposure of norfloxacin (NF) and drought (D) individually and in combination (DNF) were explored on rice (Oryza sativa) cultivar Hanyou73 through proteomics and metabolomic analysis. All treatments adversely affected chlorophyll fluorescence kinetics, antioxidant enzyme activities, rice grain composition and yield. The results showed that in DNF the antibiotic was accumulated 627% more than NF treatment in rice grains while in leaves there was no significant difference under both treatments. The proteomic revealed that differentially expressed identified proteins were involved in carbohydrate metabolism, amino acid metabolism, photosynthesis and mRNA binding. However, the metabolomics results showed that the abundance of metabolites related to RNA biosynthesis and amino acid metabolism were more affected. The disruptions caused in rice plant under DNF treatment become more severe, this makes it more susceptible than individual D and NF treatment. These findings improve our knowledge about the response of rice plant to cope with antibiotic contamination alone and in combination with drought.

Evaluating dietary exposure and risk characterization of aflatoxin B1, citrinin, and ochratoxin A co-occurrence in pigmented rice consumed in Thailand

In recent years, pigmented rice, often referred to as functional rice, has attracted increasing attention due to its perceived health benefits arising from an abundance of phytochemicals. However, there is limited information on the occurrence and risks of mycotoxins due to long-term consumption of pigmented rice. This study assessed the co-occurrence and contamination levels of aflatoxins, citrinin (CIT), and ochratoxin A (OTA) in various pigmented rice samples sourced from Thailand, and also evaluated the potential health risks for consumers. The results indicated varying levels of mycotoxin contamination among the different tested pigmented rice varieties, with aflatoxin B1 (AFB1) being the most prevalent (39.1 %), followed by CIT (17.3 %) and OTA (14.5 %). The co-occurrences of AFB1-CIT and CIT-OTA were the most prevalent combination observed in the pigmented rice samples. Although the AFB1 and CIT levels remained below regulatory limits, some samples had OTA levels exceeding these limits, though by a small percentage. Furthermore, the anthocyanin content in pigmented rice showed a weak positive correlation with the AFB1 level (p < 0.05). The estimated risk of liver cancer incidence associated with the consumption of pigmented rice containing AFB1 was in the range 0.012–0.061 cases/100,000 persons/year, depending on consumption rate and behavior. The risk posed by CIT exposure was considered negligible. However, the exposure assessments suggested a potential risk of OTA exposure, particularly in scenarios with higher consumption rates. Cumulative risk assessment of AFB1-OTA co-occurrence indicated an amplified health risk compared to single mycotoxin exposure. These findings offer valuable evidence, encouraging further research aimed at mitigating the risks associated with mycotoxin contamination in pigmented rice.

Optimizing cultivation system and pest management in different types of rice varieties

Optimizing cultivation system and pest management in different types of rice varieties

Field performance and nitrous oxide emissions of transgenic nitrogen use efficient rice lines cultivated in tropical paddy fields.

Nitrogen (N) fertilizers make up the majority of the input used in rice production, and their excess application leads to significant environmental pollution. Developing rice varieties with improved nitrogen use efficiency (NUE) is essential to maintain the sustainability of rice production. This study aims to evaluate the performance of transgenic Oryza sativa japonica cv. Kitaake expressing the barley (Hordeum vulgare) alanine aminotransferase (HvAlaAT) gene in response to different levels of N fertilizer application under tropical paddy field conditions. Results from this study demonstrate that transgenic nitrogen use efficient Kitaake rice (Kitaake NUE) displays a grain yield increase of up to 41% compared to Kitaake null. Transgenic Kitaake NUE expressing the HvAlaAT gene displays a higher N uptake and achieves a higher nitrogen use efficiency compared to control plants while maintaining lower nitrous oxide (N2O) fluxes. The reduction in N2O emissions in Kitaake NUE compared to Kitaake null ranges from 37.5 to 96.3%. The transgenic Kitaake NUE used in this study has potential as a donor to improve the nitrogen use efficiency of indica rice for better adaptability to tropical conditions.

Flexibility of parental-like or maternal-like gene expression under diverse environments contributes to combined drought avoidance and drought tolerance in a water-savinganddrought-resistance rice hybrid.

The hybrid rice variety (Hanyou73) exhibits the maternal-like (HH7A) gene expression in roots and parental-like (HH3) gene expression in leaves to obtain both advantages of drought avoidance and drought tolerance from its two parents. Rice is one of the most important crops in the world. Rice production consumes lots of water and significantly suffers from the water deficiency and drought stress. The water-saving and drought-resistance rice (WDR) confers good drought resistance and performs well in the water-saving cultivation. A hybrid WDR variety Hanyou73 (HY73) exhibited superior drought resistance compared with its parents Hanhui3 (HH3) and Huhan7A (HH7A). Studies on drought resistance related traits revealed that HY73 performed like HH3 and HH7A on drought tolerance and drought avoidance, respectively. Transcriptomes were analyzed for samples with various phytohormone treatments and abiotic stresses, in which HY73 was closer to HH3 in leaf samples while HH7A in root samples. HY73 and its parents differed largely in DEGs and GO analysis for DEGs suggested the different pathways of drought response in HH3 and HH7A. Parent-like expression analysis revealed that the higher-parent-like expression pattern was prevailing in HY73. In addition, patterns of the parent-like expression significantly transformed between abiotic-stressed/phytohormone-treated and control samples, which might help HY73 to adapt to different environments. WGCNA analysis for those parent-like expression genes revealed some drought resistant genes that should contribute to the superior drought resistance of HY73. Genetic variation on the promotor sequence was confirmed as the reason for the flexible parent-like gene expression in HY73. Our study uncovered the important roles of complementation of beneficial traits from parents and flexible gene expressions in drought resistance of HY73, which could facilitate the development of new WDR varieties.

Exogenous selenium mitigates cadmium uptake and accumulation in two rice (Oryza sativa L.) varieties in cadmium-contaminated soil

Rice grown in cadmium (Cd)-contaminated soil, is a potential threat to human health, but exogenous selenium (Se) application on rice can mitigate Cd toxicity. However, the mechanisms underlying Se mitigation of Cd stress in ratoon rice (RR) are still poorly understood. We conducted a pot experiment with moderate Cd-contaminated yellow–brown paddy soil on two rice varieties ‘Taoyouxiangzhan’ (TX) and ‘Liangyou 6326’(LY). For all treatments, 1.0 mg kg−1 sodium selenite solution was added to soil. Treatment T1 was sodium selenite only, and in the other treatments 100 mg L−1 Se solution was sprayed on the leaves at seedling stage (T2), at tillering stage (T3), and in early anthesis stage (T4). Se treatments decreased Cd accumulation in rice grains and herbage. Under foliar spraying 100 mg L−1 Se at the seedling + 1.0 mg kg−1 Se in soil (T2), leaf Cd content decreased 16.95% in the current season and grains content decreased 46.67% in the subsequent season. Furthermore, grain Se content increased 0.94 mg kg−1 for the TX variety combined with the analysis of Cd bio-accumulation factor in grains, and Se treatments effectively decreased Cd grain concentrations due to reduced Cd translocation from roots to grains. TX variety rice showed a more pronounced response to Se treatments than LY.

Effect of Ash, Crude Protein and Nitrogen in Traditional Varieties of Rice Against Sitophilus oryzae (L.) Infestation in Storage

Effect of Ash, Crude Protein and Nitrogen in Traditional Varieties of Rice Against Sitophilus oryzae (L.) Infestation in Storage

A proposed plant classification framework for smart agricultural applications using UAV images and artificial intelligence techniques

Utilizing Wireless Sensor Networks (WSNs), Internet of Things (IoTs) sensors, and Unmanned Aerial Vehicles (UAVs), in conjunction with optimization techniques and machine learning algorithms, can present a novel approach to Precision Agricultural (PA) crops. Agriculture has transitioned from traditional legacy systems to incorporate advanced smart technologies. Several complex farming problems are utilized to promote a variety of UAV sensing and Artificial Intelligence (AI) algorithms in PA applications of smart agriculture, especially in developing countries. This paper proposes the design of a conceptual UAV sensing system for crop management using a novel classification framework. UAV-based image datasets can be implemented and expanded to various types of crops. In addition, it can classify various types of rice species and detect weed farms as it consists of a multistage process for identifying and monitoring different crops. The proposed classification framework is evaluated using three different real UAV image datasets compared with Naive Bayes, Decision Tree (DT), Bagging, and Random Forest (RF) techniques. The classification performance metrics obtained are as follows: i) the WeedNet dataset with 100 % F1-score, 100 % recall, 100 % precision, and 100 % accuracy; ii) the Rice Seedling dataset with 99.5 % F1-score, 99.5 % recall, 99.5 % precision, and 99.5 % accuracy; and iii) the Rice Varieties dataset with 97.99 % F1-score, 97.99 % recall, 98.14 % precision, and 97.99 % accuracy. The success rates achieved by the proposed classification framework outperform those of other recent state-of-the-art techniques, demonstrating its efficacy in crop management applications.

Authentication of premium Asian rice varieties: Stable isotope ratios and multi-elemental content for the identification of geographic fingerprints

Over 90 percent of the world's rice is produced and consumed in the Asia-Pacific region. Varieties such as Thai Jasmine rice and Paw San (or “Myanmar pearl rice”) are globally recognised as premium, while more local high-grade varieties include the Indonesian Ciherang and Inpari. Being able to trace the origin of these products has become necessary, since they are marketed at relatively higher prices compared to other cultivars, and they often become the target of fraudulent activities. In this work, we aimed to identify variables that could distinguish the premium-producing regions within each country, by Isotope Ratio Mass Spectrometry (IRMS) and Inductively Coupled Plasma- Mass Spectrometry (ICP-MS). Low-Level Data Fusion (LLDF) followed the analysis of more than 300 authentic samples, and (O)PLS-DA models yielded very high accuracy values. The most important geo-differentiating variables (VIP>1.4) were identified as: δ13C, δ18O, δ2H, δ34S, Co, Rb, Cu, Ba and Zn.

Effects of different phosphorus and potassium supply on the root architecture, phosphorus and potassium uptake, and utilization efficiency of hydroponic rice

Phosphorus (P) and potassium (K) affect seedling growth, root configuration, and nutrient uptake in hydroponic rice, but there are few studies on all growth stages of rice. The purpose of this experiment was to determine the response characteristics of root morphology, plant physiology, and P and K uptake and utilization efficiency to different supplies of P and K. Two local conventional rice varieties (Shennong 265 and Liaojing 294) were used as experimental materials across four treatments, including HPHK (sufficient P and K supply), HPLK (sufficient P supply under low K levels), LPHK (sufficient K supply under low P levels) and LPLK (low P and K levels) in a hydroponic setting. The results showed that HPHK and HPLK significantly decreased the acid phosphatase activity of leaves and roots from full heading to filling stages when compared to LPHK and LPLK. Sufficient supply of P or K significantly increased the accumulation of P and K (aboveground, leaves, stem sheath, and whole plant) and root morphological parameters (root length, root surface area, total root volume, and tips) during major growth stages when compared to LP or LK levels. HPHK was significantly higher than other treatments in terms of dry weight and the root activity at the main growth stage, P and K uptake rates in nutrient solutions at various stages, related P and K efficiency at the maturity stage, yield, effective panicle number, and grain number per panicle. In addition, the effect of HPHK on the above indexes were significantly greater than those of single sufficient supply of P or K. In conclusion, HPHK can improve plant configuration, increase plant P and K absorption and root activity, and increase rice yield and related P and K utilization efficiency.

Detection of Quantitative Trait Loci Associated with Alkaline Tolerance Using Recombinant Inbred Line Population Derived from Longdao5 × Zhongyouzao8 at Seedling Stage.

Salt-alkaline stress is one of the most stressful occurrences, causing negative effects on plant development and agricultural yield. Identifying and utilizing genes that affect alkaline tolerance is an excellent approach to accelerate breeding processes and meet the needs for remediating saline-alkaline soil. Here, we employed a mapping population of 176 recombinant inbred lines (RILs) produced from a cross between alkali-tolerant Longdao5 and alkali-sensitive Zhongyouzao8 to identify the quantitative trait loci (QTLs) determining alkali tolerance at the seedling stage. For the evaluation of alkali tolerance, the recovered seedling's average alkali tolerance index (ATI), root number (RN), root length (RL), seedling dry weight (SW), root dry weight (RW), and seedling height (SH) were assessed, together with their relative alkaline damage rate. Under alkaline stress, the ATI was substantially negative connected with the root number, seedling height, seedling dry weight, and root dry weight; however, it was considerably positive correlated with the relative alkaline damage rate of the root number and root dry weight. A total of 13 QTLs for the root number, root length, seedling height, seedling dry weight, root dry weight, and alkali tolerance index under alkaline stress were identified, which were distributed across chromosomes 1, 2, 3, 4, 5, 7, and 8. All of these QTLs formed two QTL clusters for alkali tolerance on chromosome 5 and chromosome 7, designated AT5 and AT7, respectively. Nine QTLs were identified for the relative alkaline damage rate of the root number, root length, seedling height, seedling dry weight, and root dry weight under alkali stress. These QTLs were located on chromosome 2, 4, 6, 7, 8, 9, and 12. In conclusion, these findings further strengthen our knowledge about rice's genetic mechanisms for alkaline tolerance. This research offers clues to accelerate breeding programs for new alkaline-tolerance rice varieties.