High Yielding Rice Varieties Research Articles

Bulked Segregant RNA-Seq Analysis of Pollinated Pistils Reveals Genes Influencing Spikelet Fertility in Rice

Prezygotic isolation is important for successful fertilization in rice, significantly affecting yield. This study focused on F5:6 generation plants derived from inter-subspecific crosses (Nipponbare × KDML105) with low (LS) and high seed-setting rates (HS), in which normal pollen fertility was observed. However, LS plants showed a reduced number of pollen grains adhering to the stigma and fewer pollen tubes reaching the ovules at 4‒5 h post-pollination, compared with HS plants. Bulked segregant RNA-Seq analysis of pollinated pistils from the HS and LS groups revealed 249 and 473 differentially expressed genes (DEGs), respectively. Kyoto Encyclopedia of Genes and Genomes analysis of the HS and LS- specific DEGs indicated enrichment in metabolic pathways, pentose and glucuronate interconversions, and flavonoid biosynthesis. Several of these DEGs exhibited co-expression with pollen development genes and formed extensive clusters of co-expression networks. Compared with LS pistils, enzyme genes controlling pectin degradation, such as OsPME35 and OsPLL9, showed similar expression patterns, with higher levels in HS pistils pre-pollination. Os02g0467600, similar to cinnamate 4-hydroxylase gene (CYP73), involved in flavonoid biosynthesis, displayed higher expression in HS pistils post-pollination. Our findings suggest that OsPME35, OsPLL9, and Os02g0467600 contribute to prezygotic isolation by potentially modifying the stigma cell wall (OsPME35 and OsPLL9) and controlling later processes such as pollen-stigma adhesion (Os02g0467600) genes. Furthermore, several DEGs specific to HS and LS were co-localized with QTLs and functional genes associated with spikelet fertility. These findings provide valuable insights for further research on rice spikelet fertility, ultimately contributing to the development of high-yielding rice varieties.

A Season-wise Analysis of the Extent of Adoption of Popular Rice Varieties in Telangana, India

A Season-wise Analysis of the Extent of Adoption of Popular Rice Varieties in Telangana, India

Sub1 QTL confers submergence tolerance in rice through nitro-oxidative regulation and phytohormonal signaling

Constant change in global climate has become the most important limiting factor to crop productivity. Asymmetrical precipitations are causing recurrent flood events around the world. Submergence is one of the most detrimental abiotic stresses for sustainable rice production in the rainfed ecosystems of Southeast Asia. Therefore, the development of submergence-tolerant rice is an essential requirement to encounter food security. Submergence tolerance in rice is governed by the major quantitative trait locus (QTL) designated as Submergence1 (Sub1) near the centromere of chromosome 9. The introduction of the Sub1 in high-yielding rice varieties producing near-isogenic lines (NILs) has shown extreme submergence tolerance. The present study aimed to understand the responses of rice genotype IR64 and its Sub1 NIL IR64 Sub1 following one week of complete submergence treatment. Submergence imposed severe nitro-oxidative stress in both the rice genotypes, consequently disrupting the cellular redox homeostasis. In this study, IR64 exhibited higher NADPH oxidase activity accompanied by increased reactive oxygen species, reactive nitrogen species, and malondialdehyde buildups and cell death under submergence. Higher accumulations of 1-Aminocyclopropane-1-carboxylic acid, gibberellic acid, and Indole-3-acetic acid were also observed in IR64 which accelerated the plant growth and root cortical aerenchyma development following submergence. In contrast, IR64 Sub1 had enhanced submergence tolerance associated with an improved antioxidant defense system with sustainable morpho-physiological activities and restricted root aerenchyma formation. The comprehensive analyses of the responses of rice genotypes with contrasting submergence tolerance may demonstrate the intricacies of rice under complete submergence and may potentially contribute to improving stress resilience by advancing our understanding of the mechanisms of submergence tolerance in rice.

Development of High Yielding Rice Varieties Tolerant to Phosphorus Deficiency

Improvement of nutrient-use efficiency (NUE) in rice is important for increasing productivity. Rice varieties with tolerance to phosphorus (P) deficiency increase the productivity in P-deficient fields. Therefore, the objective of this study was to develop high yielding, P-deficiency tolerant rice varieties to enhance the NUE. High yielding and popular rice varieties (Bg300 and Bg94-1) and known P-deficiency tolerant rice varieties (H4 and At353) were used as female and male parents, respectively, in a crossing program. Single seed descent approach was used for rapid generation advancement. Bg300/At353 and Bg94-1/H4 crosses were advanced from F2 to F6 in planthouse condition under minimum fertigation for restricted growth. In F7 generation, 310 recombinant inbred lines (RIL) in both crosses were space-planted and 40 RILs were selected from each cross. Selected RILs were screened in a hydroponic system at 10 μM P level to select the best lines for P-deficiency tolerance. Multiple plant traits were used for selection and the most promising 20 rice lines were selected as the best performers under P-deficient hydroponic conditions. Marker assisted selection was carried out to confirm the presence of PSTOL1 gene. Selected rice lines were evaluated for agronomic traits and yield parameters. Ten promising rice lines were identified as high yielding lines with accepted agronomic traits.

Polyploidized rice improves plant height and yield through regulation of the expression of yield-related genes

Polyploidization is one of the most effective ways to improve plant height and yield in rice (<i>Oryza sativa</i> L.). However, the molecular mechanism of its regulation is not yet fully understood. Here, we investigated the agronomic traits of diploid (‘Balilla- 2x’) and tetraploid (‘Balilla-4x’) lines of the japonica rice variety ‘Balilla’. Compared with ‘Balilla-2x’, ‘Balilla-4x’ exhibited significantly increased plant height, spike length and yield per plant. RNA-seq analysis showed that the expression levels of yield-related genes controlling plant height and panicle development (e.g., <i>STH1</i>,<i>OsYUC9</i> and <i>OsDEP1</i>) were significantly upregulated in ‘Balilla-4x’ rice plants. These results indicated that polyploidization changed the expression of genes related to agronomic traits such as plant height and spike length, thereby increasing rice yield. is study provides a further basis for understanding the yield of rice after polyploidization and can serve as a new theoretical reference for breeding high-yielding rice varieties.

Environmental Impacts of Rice Intensification Using High-Yielding Varieties: Evidence from Mazandaran, Iran

This article aims to show the potential contribution of high-yielding rice varieties to achieve sustainable intensification in paddy farming, by focusing on a developing country. A comparative life cycle assessment of traditional vs. high-yielding varieties is carried out by comparing the area-based and yield-based results. Primary data are collected through a farm survey (49 farms in the Mazandaran province, Iran; spring 2018). The results highlight that high-yielding varieties can reduce the yield-scaled impacts. However, area-scaled impacts are subject to increase for most impact categories. Statistically significant trade-offs involve global warming potential (+13% per ha and −28% per t in high-yielding varieties) and fossil resource depletion (+15% per ha and −26% per t in high-yielding varieties). Pesticide management is the most alarming practice. High-yielding varieties increase pesticide consumption and related toxicity impacts both per t and per ha. This study is a new contribution to the literature by improving and broadening the mainstream productivity perspective of current life cycle assessment research about crop varieties. The lessons learnt from this study suggest that the trade-offs between yield-scaled and area-scaled impacts should be carefully considered by decision-makers and policymakers, especially in developing countries that, like Iran, are affected by the overexploitation of natural resources. Targeted policy and the development of farmer education and advisory services are needed to create the enabling conditions for farm management changes, including conscious use of production inputs while avoiding heuristics.

Evaluasi Mutu Fisikokimia Beras Hasil Persilangan antara Empat Padi Varietas Unggul dan Padi Liar (Oryza glaberrima dan O. rufipogon)

The physicochemical quality of rice is evaluated to ensure that it is fit for consumption and meets established quality standards. This study aims to analyze the physicochemical properties of rice strains resulting from crosses between four high-yielding varieties of rice and two wild rices so that the appropriate genotype is obtained for the development of quality rice. The research was conducted from November 2019 to March 2020 at the Quality Laboratory, Muara Experimental Garden, Rice Research Center, Bogor. The rice genotypes used were 22 strains resulting from crosses between high-yielding varieties of rice (Ciherang, Inpari 13, Inpari 10, and Situ Bagendit), and wild rice (Oryza glaberrima and O. rufipogon), 4 comparison varieties of crossbred elders, and two comparison varieties of organoleptic tests (Memberamo and IR42). Physical and chemical qualities were observed in terms of grain moisture content, grain density, broken skin rice yield, milled rice yield, head rice yield, rice length, rice shape, and rice liming, amylose content, gelatinization temperature, and organoleptic. The results showed that the strains 44-F-C21, 58-F-C21, and 59-F-C21 provided fairly good rice quality with head rice yields above 80% and higher than their respective elders (Situ Bagendit and Ciherang), and water content below 14%. These strains had characteristic characteristics, namely medium rice form, amylose content of 26.38%, and alkali score of 2-3. Most of these genotypes also exhibited high gelatinization temperatures, medium rice texture, and savory rice flavors. The genotype selected from the results of crosses between high-yielding varieties of rice and wild rice has the potential to be developed because there are genetic improvements from its elders on several physicochemical characteristics of rice. Keywords: amylose content; gelatinization temperature; physicochemical properties; rice lines; wild rice

An Alarming Decline in the Nutritional Quality of Foods: The Biggest Challenge for Future Generations' Health.

In the last sixty years, there has been an alarming decline in food quality and a decrease in a wide variety of nutritionally essential minerals and nutraceutical compounds in imperative fruits, vegetables, and food crops. The potential causes behind the decline in the nutritional quality of foods have been identified worldwide as chaotic mineral nutrient application, the preference for less nutritious cultivars/crops, the use of high-yielding varieties, and agronomic issues associated with a shift from natural farming to chemical farming. Likewise, the rise in atmospheric or synthetically elevated carbon dioxide could contribute to the extensive reductions in the nutritional quality of fruits, vegetables, and food crops. Since ancient times, nutrient-intense crops such as millets, conventional fruits, and vegetables have been broadly grown and are the most important staple food, but the area dedicated to these crops has been declining steadily over the past few decades and hastily after the green revolution era due to their poorer economic competitiveness with major commodities such as high-yielding varieties of potato, tomato, maize, wheat, and rice. The majority of the population in underdeveloped and developing countries have lower immune systems, are severely malnourished, and have multiple nutrient deficiency disorders due to poor dietary intake and less nutritious foods because of ignorance about the importance of our traditional nutrient-rich diets and ecofriendly organic farming methods. This critical review emphasizes the importance of balance and adequate nutrition as well as the need to improve soil biodiversity and fertility: those are main causes behind the decline in nutritional density. There is also emphasis on a possible way out of alleviating the decline nutritional density of food crops for the health and well-being of future generations.

MiR396b/GRF6 module contributes to salt tolerance in rice.

Salinity, as one of the most challenging environmental factors restraining crop growth and yield, poses a severe threat to global food security. To address the rising food demand, it is urgent to develop crop varieties with enhanced yield and greater salt tolerance by delving into genes associated with salt tolerance and high-yield traits. MiR396b/GRF6 module has previously been demonstrated to increase rice yield by shaping the inflorescence architecture. In this study, we revealed that miR396b/GRF6 module can significantly improve salt tolerance of rice. In comparison with the wild type, the survival rate of MIM396 and OE-GRF6 transgenic lines increased by 48.0% and 74.4%, respectively. Concurrent with the increased salt tolerance, the transgenic plants exhibited reduced H2O2 accumulation and elevated activities of ROS-scavenging enzymes (CAT, SOD and POD). Furthermore, we identified ZNF9, a negative regulator of rice salt tolerance, as directly binding to the promoter of miR396b to modulate the expression of miR396b/GRF6. Combined transcriptome and ChIP-seq analysis showed that MYB3R serves as the downstream target of miR396b/GRF6 in response to salt tolerance, and overexpression of MYB3R significantly enhanced salt tolerance. In conclusion, this study elucidated the potential mechanism underlying the response of the miR396b/GRF6 network to salt stress in rice. These findings offer a valuable genetic resource for the molecular breeding of high-yield rice varieties endowed with stronger salt tolerance.

Transcriptomic analysis of salt-tolerant and sensitive high-yield japonica rice (Oryza sativa L.) reveals complicated salt-tolerant mechanisms.

Developing and cultivating rice varieties is a potent strategy for reclaiming salinity-affected soils for rice production. Nevertheless, the molecular mechanisms conferring salt tolerance, especially in conventional high-yield japonica rice varieties, remain obscure. In this study, Zhendao 23309 (ZD23309) exhibited significantly less grain yield reduction under a salt stress gradient than the control variety Wuyunjing 30 (WYJ30). High positive correlations between grain yield and dry matter accumulation at the jointing, heading and maturity stages indicated that early salt tolerance performance is a crucial hallmark for yield formation. After a mild salt stress (85 mM NaCl) of young seedlings, RNA sequencing (RNA-seq) of shoot and root separately identified a total of 1952 and 3647 differentially expressed genes (DEGs) in ZD23309, and 2114 and 2711 DEGs in WYJ30, respectively. Gene ontology (GO) analysis revealed numerous DEGs in ZD23309 that play pivotal roles in strengthening salt tolerance, encompassing the response to stimulus (GO:0050896) in shoots and nucleoside binding (GO:0001882) in roots. Additionally, distinct expression patterns were observed in a fraction of genes in the two rice varieties under salt stress, corroborating the efficacy of previously reported salt tolerance genes. Our research not only offers fresh insights into the differences in salt stress tolerance among conventional high-yield rice varieties but also unveils the intricate nature of salt tolerance mechanisms. These findings lay a solid groundwork for deciphering the mechanisms underlying salt tolerance.

THE CONTRIBUTION OF TRANSGENIC RICE TO ENHANCE GRAIN YIELD

Breeders' main goal is to increase the proportion of high-quality rice produced overall. To create effective rice breeding strategies, possible yield-related loci have been mined. many researchers are using transgenic strategies as cutting-edge methods to increase rice productivity. Quantitative trait loci (QTLs) play a pivotal role in governing grain yield in Oryza sativa L., commonly known as rice. The genes contributing to QTLs that determine grain size, length, and weight have been successfully identified. Numerous genes are upregulated to enhance the overall yield of rice. Recent advancements have led to the discovery of genes and QTLs specifically associated with rice yield. Through an in-depth analysis of various yield characteristics, including grain weight, thousand grain weight, grain length, grain width, grain yield per plant, grain number per panicle, and panicles per plant, we conducted a comprehensive review using extensive literature research and public domain databases. Additionally, we explored the progress made in transgenic technology and advanced genomic techniques. The compiled information on genes and QTLs related to yield enhancement aims to provide a valuable resource. The integrated analysis of existing data on genes and/or QTLs provide evidence on potential combinations for creating superior genotypes that combine high yield across multiple traits. Integration of molecular markers, transgenic techniques and conventional breeding as discussed in this extensive review opens up the prospect of developing high yielding rice varieties

Front-line Demonstration: An Effective Communication Approach for Dissemination of Sustainable Rice Production Technology

During four consecutive Kharif seasons in the years 2016, 2017, 2018 and 2019, front-line demonstrations were carried out in farmer's fields by the College of Agriculture, Waraseoni (Balaghat), Madhya Pradesh in the agroclimatic zone of the Chhattisgarh plains to assess the performance of rice Hybrids / varieties JRH-5, JRH-19, JR-81 and JRB-1 (developed by Jawaharlal Nehru Agriculture University, Jabalpur) under irrigated ecosystem. Front-line demonstrations, or FLDs, were carried out using a scientific package of rice technology practices. The yield and economic data of the plots that were on display were examined, evaluated, and examined with farmer practices (MTU-1010). With only an average of Rs. 2625/ha as an additional input cost in demonstrations using enhanced production technologies in FLDs, the mean grain yield increased by 23.80% over current farmer practices.Extension gap (10.48 q/ha), Technology gap (10.26 q/h) and the technology index is 15.79%. It is concluded that wide gap existed in potential and demonstration yield in high yielding rice varieties due to technology and extension gap in Balaghat District of Madhya Pradesh.By conductingfront line demonstrations of proven technologies, yield potential of rice can be increased to a greatextent. This will substantially increase the income as well as the livelihood of the farming community.

Crop establishment methods and herbicide mixtures induced weed dynamics, productivity, and profitability of summer rice

Rice farmers face challenges in achieving higher yield and profit during the summer season due to improper establishment and weed control. To address this, a study was conducted to assess the effects of herbicide combinations on the growth and yield of CR Dhan 206 (Gopinath), a high-yielding rice variety. The research took place from January to May 2022 at the PG Research Farm of M. S. Swaminathan School of Agriculture, Centurion University of Technology and Management, Paralakhemundi, Odisha. The experiment followed a split plot design with two main plots (transplanted rice and wet seeded rice) and five subplots (fenoxaprop-p-ethyl + ethoxysulfuron (Tank mix) @ (50+15) g ha-1 at 18 days after transplanting/sowing (DAT/S); triafamone + ethoxysulfuron (Ready mix) @ (45+22.5) g ha-1 at 12 DAT/S; pretilachlor + bensulfuron-methyl (Ready mix) @ (600+60) g ha-1 at 4 DAT/S; weed-free (Hand weeding at 20,40,60 DAT/S); and weedy check) replicated thrice. The dominant weeds observed were Echinochloa colona, Leptochloa chinensis, Cyanotis auxiliaris, Physalis minima, Ludwigia parviflora, Cyperus iria, and Fimbristylis miliacea. Results indicated that the establishment methods did not significantly affect crop growth, yield attributes, crop yield, and weed infestation. However, the application of triafamone + ethoxysulfuron in both transplanted and wet seeded rice demonstrated superior growth, yield, weed control, and comparable results to the weed-free check. The combination of wet seeded rice and triafamone + ethoxysulfuron showed the highest net return and benefit-cost ratio, suggesting its recommendation for effective weed control and profitability in rice farming in summer season.

Cold-Tolerant and Short-Duration Rice (Oryza sativa L.) for Sustainable Food Security of the Flash Flood-Prone Haor Wetlands of Bangladesh

Rice cultivation in the low-lying basin-like wetlands, known as the Haor, is often affected by early flash floods during the first two weeks of April. The flooding is mainly caused by heavy rainfall and water surging downstream from the Meghalaya hills in India. This flash flood poses a significant threat to rice production, risking the country’s food security. Dry winter (Boro) rice is the primary food source throughout the year in the Haor region. Flash floods are the most catastrophic, affecting about 80% or even the entire rice yield. In 2017, a loss of 0.88 million metric tons of Boro rice in Haor regions cost the nation USD 450 million. To escape flash floods, it is recommended to sow Boro rice earlier, between the last week of October and the first week of November, instead of around 15 November so rice may be harvested by the last week of March before the onset of flash floods. However, early sowing has a possibility of causing grain sterility due to cold spells when the booting and heading stages of rice inevitably coincide with the cold period between 15 January and 7 February. The minimum temperature in the Haor regions ranges from 11 to 15 °C during this time. Rice is especially susceptible to low average temperatures (<20 °C) during the reproductive stage, leading to pollen abortion and the malformation of immature microspores. Low temperatures mainly impact rice cultivation in Haor regions during the reproductive phase, resulting in the degeneration of the spikelets, partial panicle exertion, and increased spikelet sterility, leading to a decrease in grain yield. Over two million hectares of Boro rice have been damaged by extreme cold spells in recent years, resulting in partial or total yield loss. To overcome the threats of flash floods and cold injury, breeding short-duration and cold-tolerant rice varieties is crucial. We assume that an economic benefit of USD 230 million per year could be achieved through the development and adoption of short-duration and cold-tolerant high-yielding rice varieties in the Haor regions of the country. In this review article, the authors summarized the problems and outline a way forward to overcome the flash flood and cold injury of Boro rice cultivation in the Haor districts of the country. Furthermore, the authors discussed the various forms and scenarios of cold damage and the global existence of cold-tolerant rice cultivars. Based on the available data from earlier research, a potential way of mitigating flash floods and cold devastation was suggested.

Advanced Mutant Line Developed from Fatemadhan Shows Salinity Tolerance at both Seedling and Reproductive Stages

The generation of high-yielding rice mutants and their assessment under salt stress offers a great possibility to isolate salt tolerant line(s) with desired trait of interest. Two separate experiments were conducted at the seedling and reproductive stages of rice to assess the level of salinity tolerance of few advanced high-yielding rice mutants. In the first experiment, rice seedlings were grown under hydroponic conditions and 14-day-old seedlings were subjected to salt stress (EC=10 dS/m; 7 days). Salt stress caused significant reduction in root and shoot length and biomass and leaf chlorophyll content; however, a little reduction was found in the mutant Line-1. In contrast, a sharp increase in shoot Na+/K+ ratio was found in all the genotypes except, Binadhan-10, FL-478 and the mutant Line-1, which exhibited little increased ratio. The second experiment involved exposure of plant to salt stress (EC=10 dS/m) for three weeks at the late booting stage in a sizable plastic tub filled with field soil. Salt stress resulted in a significant decrease in yield and yield attributing traits in all the genotypes except Binadhan-10. Grain yield per panicle was found significantly positive correlation with panicle length, the number of filled grains per panicle, and 100-seed weight under both control and salt stress conditions. Based on the studied traits and stress tolerance indices, Binadhan-10 and mutant Line-1 categorized as salt tolerant and rest of the genotypes were categorized as susceptible, which is also evident from the biplot of principal component analysis. Considering the results from both of the experiments, mutant Line-1 was found tolerant genotype at both seedling and reproductive stage. However, further studies are required to determine the genetic issues controlling the salinity tolerance in mutant Line-1 and the high-yield potential of mutant Line-65 under control condition in a way to develop salt tolerant and high-yielding rice varieties, respectively.

Floods stress in lowland rice production: experiences of rice farmers in Kilombero and Lower-Rufiji floodplains, Tanzania

The resilience of rice production to floods is a crucial aspect of agricultural development in flood-prone regions. However, little is known about the farming practices and challenges of rice farmers in two river basins in Tanzania: Lower-Rufiji and Kilombero, where rice is the main crop grown. This study aimed to investigate the experiences of farmers in these two rice-growing floodplains regarding the impact of floods on lowland rice production and farmer livelihoods, and the strategies they use to cope with floods. The study used a mixed-methods approach that involved household surveys, key informant interviews, and transect walks to collect data from 180 rice farmers and 14 experts and community leaders. The data analysis revealed that floods were the dominant stressor affecting rice production, occurring mostly during the long rainy season and experienced by all farmers in both locations. Floods not only caused significant crop losses, especially in Lower-Rufiji where farmers reported losing between 75 and 100% of their yield in cases of extreme floods, but also made it difficult to establish and manage crops, leading to crop land abandonment. Floods also affected the livelihoods of rice farmers by forcing them to abandon, rent, or sell their farms. Coexistence of floods with other biotic and abiotic stresses such as crop diseases and droughts also limited the use of short maturing high yielding rice varieties. Farmers have adopted on-farm strategies such as adjusting planting schedules, using different varieties of rice, changing to other crops or activities after the floods to cope with floods, but these practices face numerous challenges. The study recommends the development of early warning systems, breeding for flood-tolerant rice varieties, introgression of tolerance traits to multiple stresses and improving crop establishment methods to enhance the resilience of farmers to floods and other extreme climate events.

Promising physiological traits associated with nitrogen use efficiency in rice under reduced N application.

Higher grain yield in high-yielding rice varieties is mostly driven by nitrogen (N) fertilizer applied in abundant amounts leading to increased production cost and environmental pollution. This has fueled the studies on nitrogen use efficiency (NUE) to decrease the N fertilizer application in rice to the possible extent. NUE is a complex physiological trait controlled by multiple genes, but yet to be completely deciphered in rice. With an objective of identifying the promising physiological traits associated with NUE in rice, the performance of 14 rice genotypes was assessed at N0, N50, N100, and N150 for four (two wet and two dry) seasons using agro-morphological, grain yield, flag leaf traits, photosynthetic pigment content, flag leaf gas exchange traits, and chlorophyll fluorescence traits. Furthermore, the data were used to derive various NUE indices to identify the most appropriate indices useful to screen rice genotypes at N50. Results indicate that with the increase in N application, cumulative grain yield increased significantly up to N100 (5.02t ha-1); however, the increment in grain yield was marginal at N150 (5.09t ha-1). The mean reduction of grain yield was only 26.66% at N50 ranging from 15.0% to 34.2%. The significant finding of the study is the identification of flag leaf chlorophyll fluorescence traits (Fv/Fm, ΦPSII, ETR, and qP) and Ci associated with grain yield under N50, which can be used to screen N use efficient genotypes in rice under reduced N application. Out of nine NUE indices assessed, NUpE, NUtE, and NUEyield were able to delineate the high-yielding genotypes at N50 and were useful to screen rice under reduced N conditions. Birupa emerged as one of the high yielders under N50, even though it is a moderate yielder at N100 and infers the possibility of cultivating some of the released rice varieties under reduced N inputs. The study indicates the possibility of the existence of promising genetic variability for grain yield under reduced N, the potential of flag leaf chlorophyll fluorescence, and gas exchange traits as physiological markers and best suitable NUE indices to be deployed in rice breeding programs.

Towards Sustainable Enhanced Rice Production for Meeting Food Grain Self-sufficiency: A Strategic Food Outlooks of Bangladesh By 2030 And 2050

The present study forecasted the demand and supply of food grains in Bangladesh by 2030 and 2050, by using Box and Jenkin’s ARIMA model. It is the 8th most populous country in the world. Cereals provide a major part of the calorie intake in Bangladesh, but their share in the total calorie supply is predicted to decrease over the years, while it is from non-cereal items will have an increasing trend from 2030 to 2050. The total crop demand for rice is projected to be 39.1 MMTs in 2030 and 42.6 MMTs in 2050. The Business as Usual Scenario predicted that there will be a marginal surplus of rice in 2030 and 2050 but the pessimistic scenario projected that there could be a deficit of 3.62 MMTs in 2030 and 1.93 MMTs in 2050 due to climatic shocks. Although the country has achieved self-sufficiency in rice, the projections reflected that its food security could be threatened due to natural calamities. Supportive government policy with increased investment in research and extension is needed for generating climate-resilient high-yielding rice varieties with production technology and requiring the establishment of a strategic rice grain reserve for the country to meet emergency food crises during natural calamities.

Impact of Front Line Demonstrations in Improving Rice Productivity and Profitability in Jaunpur District of Uttar Pradesh, India

A study was carried out during Kharif, 2019 to assess the impact of Frontline Demonstrations (FLDs) on productivity and profitability of rice crop in Jaunpur district of Uttar Pradesh. The FLDs were conducted by the ICAR-Indian Agricultural Research Institute, Regional Station Pusa, Samastipur, Bihar, under the IARI-Outreach Programme to know the yield gap, technology gap, extension gap, economic return, extent of farmer’s satisfaction, and constraints faced by the farmers, especially paddy growers. The critical inputs were identified in existing production technology through personal interaction, group meetings, and discussions with farmers and scientists. Improved variety, soil testing, seed treatment, integrated nutrient management, weed management, and pest and disease management are among the improved technologies. The result showed that switching from traditional farming methods to more advanced production technologies can result in yields of 30.00 percent and net returns of 27.00 percent. The extension gap of 1.20 t/ha, technological gap (0.55 t/ha), and technology index (9.57%) were registered for the Pusa Sugandha-5 variety. An additional returns of ₹16884.33/ha was obtained with an additional investment of ₹8395.67/ha, coupled with scientific monitoring of demonstrations and the use of rice varieties during investigations, which also influenced the economic returns per unit area. The constraint that was found to be the most difficult to overcome was the lack of improved, high-yielding rice varieties. In order to increase their yield and increase the production and productivity of rice in Uttar Pradesh, farmers in the area are advised to adopt new rice varieties as well as a recommended improved package of practices and technologies.

Genetic Analysis of Quantitative Traits, Gall Midge and Brown Spot Tolerance in Rice (Oryza sativa L.) Genotypes under Irrigated Ecosystem

Gall midge and brown spot of rice are a fungal disease that affect both seedlings and mature plants. To investigate resistance of rice to this disease twenty nine rice cultures were evaluated under irrigated ecosystem at Regional Agricultural Research Station, Jagtial during kharif, 2020. High heritable estimates were observed for all the 8 traits studied. High estimates of heritability was recorded for important yield attributes viz., days to 50% flowering (91.4, 11.24), plant height (77.8, 9.53), 1000-grain weight (98.4, 54.5), number of grains per panicle (78.3, 40.18) and grain yield (98.7, 33.87) indicated that these traits were under the control of additive genes. Significantly positive correlations were recorded with plant height, Number of productive tillers per plant and 1000 seed weight at both genotypic and phenotypic levels, the results clearly indicated that long duration genotypes with more height and bolder grains contribute for more grain yield. Among the eight traits studied, 1000 grain weight contributed highest (67.8%) towards total divergence followed by days to 50% flowering (11.5%), number of grains per panicle (6.06) and Galls midge incidence percentage (6.06%). Genotypes, JGL 38957 of cluster II, JGL 38950 of cluster III, JGL 38935 of cluster IV and JGL 38921 of Cluster VII could be the best source to develop brown spot, gall midge resistance and high yielding rice varieties.