World Rice Research Articles

Nematode Attacks and their Influence on Farming Economics

Nematode attack is among the factors significantly reducing the world's rice production, to the extent of affecting farming economics and global food security. One of the factors involved in the decline in production is the prevalence of rice diseases and pests, among which are nematodes. Therefore, this study was conducted to identify the level of farmers’ knowledge on the symptoms of nematode infection in Pasir Panjang, which is situated in the rice cultivation area, namely Integrated Agricultural Development Area (IADA), of Northwest Selangor. The study also analyzed the effects of nematode attacks on farming economics. Descriptive analysis was performed on 86 randomly selected samples of farmers whose crops had often been attacked by nematodes. The results of the study found that the farming community had knowledge of the symptoms of nematode infestation in rice crop fields. Analysis of the study results showed that farmers were significantly affected by nematode attacks on their rice crops. The effects of attack could be seen from the reduced income and economic levels of the farmers and consequent increase in management costs, in addition to the increasing costs of purchasing pesticides and fertilizers. Production output and yield quality also declined. This situation has negatively impacted the quality of life of these farmers. The implications of this study inform the strategies for integrated and continuous disease and pest control to ensure that the country's food security is more stable.

The Impact of Blast Disease: Past, Present, and Future.

Rice blast disease is both the most explosive and potentially damaging disease of the world's rice (Oryza sativa) crop and a model system for research on the molecular mechanisms that fungi use to cause plant disease. The blast fungus, Magnaporthe oryzae, is highly evolved to sense when it is on a leaf surface; to develop a pressurized cell, the appressorium, to punch through the leaf cuticle; and then to hijack living rice cells to assist it in causing disease. Host specificity, determining which plants particular fungal strains can infect, is also an important topic for research. The blast fungus is a moving target, quickly overcoming rice resistance genes we deploy to control it, and recently emerging to cause devastating disease on an entirely new cereal crop, wheat. M. oryzae is highly adaptable, with multiple examples of genetic instability at certain gene loci and in certain genomic regions. Understanding the biology of the fungus in the field, and its potential for genetic and genome variability, is key to keep it from adapting to life in the research laboratory and losing relevance to the significant impact it has on global food security.

Rice blast: strategies and challenges for improving genetic resistance

Rice blast, caused by the fungus Pyricularia oryzae L., is considered one of the main threats to world rice production. The development of resistant cultivars is one of the best and sustainable control alternatives. Plant breeding efforts have been accelerated by genetic mapping (linkage and associative) and marker assisted selection. On the other hand, genomic editing techniques, such as meganucleases (MNs), Zinc-finger nucleases (ZFNs), Transcription Activator-like Effector Nucleases (TALENs) and Clustered Regularly Interspaced Short Palindrome Repeats/CRISPR-associated protein 9 (CRISPR/Cas9), can be used to promote specific genetic modifications. Likewise, transgenics can also be used to manipulate specific genes. In this sense, this work aims to characterize rice blast and elucidate available biotechnological alternatives to accelerate the development of improved rice cultivars resistant to rice blast.

The Impact of Oil Price Shock on Rice Prices in Asean Area: A Framework

The conditions of the world rice market and the domestic rice market are unstable markets and are heavily influenced by external factors. There are many factors that can affect the price of unhulled rice and rice at the farm level, one of which is the effect of the integration of world and domestic rice markets. Thus the events or shocks that occur on the world market will affect the conditions of the domestic rice market. External factors affecting rice trade include petroleum. Oil as one of the factors influencing changes in the demand and supply of various traded commodities because of its vital role. Oil price fluctuations are often used as a benchmark for the stability of world trade conditions.Research specifically on the impact of rice was carried out by Chintia (2013) which states that oil price shocks cause domestic rice prices to have a fluctuating pattern and have an increasing trend, but domestic rice prices always fluctuate on trend. An attractive characteristic of the domestic rice price is that it is always above the world rice price. This occurs because rice is a commodity that has many interventions by the government in maintaining domestic rice price stability and maintaining the purchasing power of the public as consumers and farmers as producers. In the short term, the domestic rice price is influenced by the domestic rice price itself, the imported rice price, and the world crude oil price. In the long run, the domestic rice price is influenced by world rice prices, imported rice prices, and rice production. This paper will discuss the framework for the impact of oil shocks on rice prices in the ASEAN region. This framework is the basis for the stages in conducting further research Keywords: Impact, Rice, oll price, Rice, ASEAN

Understanding on Climate Resilient Practices for Rainfed Rice-A Review

Rice is one of the major staples feeding around 3.5 billion people in the world. Rainfed rice area account for 33% of the total world rice production. Its cultivation is vulnerable to changes in temperature and rainfall. Due to global climate changes, it is essential to analyze and characterize the weather parameters like rainfall, temperature, solar radiation etc., over a region for identifying location specific sowing time. A scientific approach based on appropriate understanding of weather resources and its application for efficient crop management can help in achieving higher productivity. Various studies revealed that changes in microclimate by altering sowing dates has great role to play during vegetative and reproductive stages of the crop and also nutrient content and its uptake which ultimately affects the yield potential. Studies also showed that delayed sowing and transplanting time can significantly affect on the infestation of pest and diseases.

The Impacts of Covid-19: An Econometric Analysis of Crude Oil Prices and Rice Prices in the World

This study targeted to disclose the impact of COVID-19 on the relationship among world crude oil prices and world rice prices. It depended on data collected from different resources and covered the period extend from Jan. 2016 to May 2020. The data was divided into two periods: before COVID-19 from Jan. 2016 to Nov. 2019 and after the outbreak of COVID-19 from Dec. 2019 to May 2020. Engel-Granger Two Steps Procedure and ARDL bounds methods of analysis were used to analyze data before and after outbreaks of COVID-19, respectively. The result for the period before outbreaks of covid-9 revealed long-run co-integration among crude oil and rice prices series. Also, it recorded that the coefficient of adjustment parameter for rice showed negative (-0.349) and significant (critical t-value= -3.29), referring to the present of short-run relationship and meaning that model able to correct its past time instability. While the result for the period after outbreaks of COVID-19 didn't discover any the long run relationship between world crude oil prices and world rice prices. This result may be due to the consequences and lockdown of COVID-19. Consequently, these results may put down world food insecurity situations.

Investigation of the Genetic Diversity of a Rice Core Collection of Japanese Landraces using Whole-Genome Sequencing.

The Rice Core Collection of Japanese Landraces (JRC) consisting of 50 accessions was developed by the genebank at the National Agriculture and Food Research Organization (NARO) in 2008. As a Japanese landrace core collection, the JRC has been used for many research projects, including screening for different phenotypes and allele mining for target genes. To understand the genetic diversity of Japanese Landraces, we performed whole-genome resequencing of these 50 accessions and obtained a total of 2,145,095 single nucleotide polymorphism (SNPs) and 317,832 insertion–deletions (indels) by mapping against the Oryza sativa ssp. japonica Nipponbare genome. A JRC phylogenetic tree based on 1,394 representative SNPs showed that JRC accessions were divided into two major groups and one small group. We used the multiple genome browser, TASUKE+, to examine the haplotypes of flowering genes and detected new mutations in these genes. Finally, we performed genome-wide association studies (GWAS) for agronomical traits using the JRC and another core collection, the World Rice Core Collection (WRC), comprising 69 accessions also provided by the NARO genebank. In leaf blade width, a strong peak close to NAL1, a key gene for the regulation of leaf width, and, in heading date, a peak near HESO1 involved in flowering regulation were observed in GWAS using the JRC. They were also detected in GWAS using the combined JRC + WRC. Thus, JRC and JRC + WRC are suitable populations for GWAS of particular traits.

Development of blast-resistant rice varieties based on application of DNA technologies

Diseases of crops are the main reason for the decrease in yield and product quality. Blast is the most dangerous disease in all areas of world rice cultivation. The most effective, economically viable, and environmentally friendly strategy to combat it is the development of resistant varieties. The use of molecular genetic markers (DNA markers) linked to the loci of blast resistance is relevant in this direction. The objective of the study was to introgress and pyramid genes effective in the south of Russia for race-specific resistance to blast Pi ta, Pi-b, Pi-1, Pi-2, Pi-33, Pi-40 into the genotypes of highly productive rice varieties of domestic breeding to obtain new forms resistant to P. oryzae. To achieve this, varieties Flagman and Boyarin were hybridized with the donors of resistance to blast IR-36, Bl-1, C101-Lac, C101Lac-A-51, IR 83260-2-10-5-2-1-B, which have the genes Pi-ta, Ρi-b, Pi-1 + Pi-33, Pi-2, Pi-40, respectively, with a growing season of more than 150 days. Three backcrosses were carried out and the breeding material was obtained. Several samples with high rates of milled rice quality and blast resistance, productivity, and other economically valuable traits were identified. The program for combining the genes of resistance to blast was performed. The hybridization of the obtained genotypes with the integrated Pi genes between themselves in their various combinations was carried out. The result was a breeding variety with three resistance genes (Pi-1; Pi-2; Pi-33). The cultivation of such varieties in production will reduce the use of chemical protective equipment and avoid pollution of grain ecosystems.

Studies of rice Hd1 haplotypes worldwide reveal adaptation of flowering time to different environments.

Rice domestication/adaptation is a good model for studies of the development and spread of this important crop. Mutations that caused morphological and physiological change, followed by human selection/expansion, finally led to the improvement of phenotypes suitable for different kinds of environments. We used the sequence information for Heading date 1 (Hd1) gene to reveal the association between sequence changes and flowering phenotypes of rice in different regions. Seven loss-of-function hd1 haplotypes had been reported. By data-mining the genome sequencing information in the public domain, we discovered 3 other types. These loss-of-function allele haplotypes are present in subtropical and tropical regions, which indicates human selection. Some of these haplotypes are present locally. However, types 7 and 13 are present in more than one-third of the world's rice accessions, including landraces and modern varieties. In the present study, phylogenetic, allele network and selection pressure analyses revealed that these two haplotypes might have occurred early in Southeastern Asia and then were introgressed in many local landraces in nearby regions. We also demonstrate that these haplotypes are present in weedy rice populations, which again indicates that these alleles were present in rice cultivation for long time. In comparing the wild rice sequence information, these loss-of-function haplotypes occurred in agro but were not from wild rice.

Natural variation of diterpenoid phytoalexins in cultivated and wild rice species

Rice (Oryza sativa) leaves accumulate phytoalexins in response to pathogen attack. The major phytoalexins in rice are diterpenoids such as momilactones, phytocassanes, and oryzalexins. We analyzed the abundance of momilactones A and B and phytocassanes A and D in UV-light-irradiated leaves of cultivars from the World Rice Core Collection (WRC). Both types of phytoalexins were detected in most cultivars; however, their accumulated amounts varied greatly from cultivar to cultivar. The amounts of momilactones A and B tended to be higher in japonica cultivars than those in indica cultivars. However, the accumulated amounts of phytocassanes were not related to differences in subspecies. In addition, variation in phytoalexin content was observed for seven wild rice species. During the analysis of momilactone A in cultivars from the WRC, two unknown compounds were detected in‘Jaguary’ and ‘Basilanon’. We isolated these compounds from UV-light-irradiated leaves and determined their structures. The compound isolated from ‘Jaguary’ was an isomer of momilactone A that had an abietane skeleton, while that from ‘Basilanon’ was di-dehydrogenated phytocassane A; these compounds were denoted as oryzalactone and phytocassane G. Oryzalactone accumulated in only three cultivars, whereas phytocassane G accumulated in almost all of the cultivars from the WRC. These findings indicate the existence of large natural variation in the phytoalexin composition in rice.

Legacy of soil health improvement with carbon increase following one time amendment of biochar in a paddy soil – A rice farm trial

“4 per 1000 Initiative” launched at COP21 has strongly recommended that increasing soil organic carbon (SOC) is a global imperative. However, the strategies to improve agricultural soil functioning and health by an increase in soil C have been poorly addressed. In a rice farm trail, topsoil samples were collected in 2015 respectively in a field amended with biochar (BA) (equivalent to 10 t ha−1) in 2009 and an adjacent field with no biochar (NB). Soil aggregation, biochemical activities and microbial communities of the samples were analyzed with microscopic, micro-biochemical and molecular assays respectively. Compared to NB field, SOC storage increased by 45%, total and available nitrogen pool enhanced by approximately 30% while the bulk density decreased and soil pH unchanged in BA field. A 25% increase in mean weight diameter of water stable aggregates was observed in the BA compared to NB field. Correspondingly, microbial biomass nitrogen and enzyme activities in BA field was enhanced both by approximately 30% compared to NB field. Furthermore, with community structure altered, a moderate (32%) increase in total bacterial abundance and a significant decrease in microbial abundance of amino acid metabolism and fungal pathotrophs were observed in BA field compared to NB field. This could link to the higher (10%) grain yield with lower yield inter-annual variability in BA field compared to NB field, reported previously. All these changes clearly demonstrated a legacy of paddy soil health improvement over years following one time biochar amendment. Overall, addition of biochar to the clayey nutrient rich paddy soil could sustain an increase in SOC, soil aggregation and soil health functioning, with positive changes in microbial community over years. Thus, carbon increase as per required by the “4 per 1000 Initiative” could be a mechanistic driver to enhance soil fertility and improve soil-(plant) health for ensuring food production in world rice agriculture facing land degradation and climate change impacts, which could be assisted by biochar from crop residue in an approach of circular economy.

Understanding the Stickiness of Commodity Supply Chains Is Key to Improving Their Sustainability

Summary Commodity trade is central to the global economy but is also associated with socio-environmental impacts, for example, deforestation, especially in producer countries. It is crucial to understand how geographic sourcing patterns of commodities and commercial relationships between places and actors influence land-use dynamics, socio-economic development, and environmental degradation. Here, we propose a concept and methodological approach to analyze the geographic stickiness of commodity supply chains, which is the maintenance of supply network configurations over time and across perturbations. We showcase policy-relevant metrics for all Brazilian soy exports between 2003 and 2017, using high-resolution supply chain data from www.trase.earth . We find that the Brazilian soy traders with the largest market share exhibit stickier geographic sourcing patterns, and that the supply network configurations between production places and traders become increasingly sticky in subsequent years. Understanding trade stickiness is crucial for supply chain accountability, because it directly affects the effectiveness of zero-deforestation commitments.

SIFAT KIMIA DAN SENSORI SERBUK BERAS HITAM DENGAN VARIASI METODE PEMASAKAN DAN PENAMBAHAN BUBUK KEDELAI

Black rice is one of the world's rice varieties, in addition to white rice, brown rice, and brown rice. The content of anthocyanin and its antioxidant activity is greater than other types of rice. Therefore, this research done as one effort to exploit black rice. The general purpose of this study was to determine the levels of anthocyanin, antioxidant activity, sensory properties and determine the best treatment. Cooking methods (roasting and oven) and the addition of soy powder (0, 10gr, 20gr, 30gr, 40gr). This study used a Factorial Completely Randomized Design with anthocyanin and DPPH antioxidant activity. The result of statistical test shows hat cooking method and addition of soybean powder have an effect on anthocyanin content, antioxidant activity and sensory properties. The best treatment was roasting and 10 gr from 10 gr weight of black rice with anthocyanin content 4,67 ppm, antioxidant activity 29,80%, sensory value 2,77 (close to likes) and protein value 14,68% . The value of water content in powdered black rice powder also in accordance with standard water content in powder powder ranges from 3% to 5%.

SMRT sequencing of the Oryza rufipogon genome reveals the genomic basis of rice adaptation

Asian cultivated rice is believed to have been domesticated from a wild progenitor, Oryza rufipogon, offering promising sources of alleles for world rice improvement. Here we first present a high-quality chromosome-scale genome of the typical O. rufipogon. Comparative genomic analyses of O. sativa and its two wild progenitors, O. nivara and O. rufipogon, identified many dispensable genes functionally enriched in the reproductive process. We detected millions of genomic variants, of which large-effect mutations could affect agronomically relevant traits. We demonstrate how lineage-specific expansion of gene families may have contributed to the formation of reproduction isolation. We document thousands of genes with signatures of positive selection that are mainly involved in the reproduction and response to biotic- and abiotic stresses. We show that selection pressures may serve as forces to govern substantial genomic alterations that form the genetic basis of rapid evolution of mating and reproductive systems under diverse habitats.

Whole-Genome Sequencing of the NARO World Rice Core Collection (WRC) as the Basis for Diversity and Association Studies.

Genebanks provide access to diverse materials for crop improvement. To utilize and evaluate them effectively, core collections, such as the World Rice Core Collection (WRC) in the Genebank at the National Agriculture and Food Research Organization, have been developed. Because the WRC consists of 69 accessions with a high degree of genetic diversity, it has been used for >300 projects. To allow deeper investigation of existing WRC data and to further promote research using Genebank rice accessions, we performed whole-genome resequencing of these 69 accessions, examining their sequence variation by mapping against the Oryza sativa ssp. japonica Nipponbare genome. We obtained a total of 2,805,329 single nucleotide polymorphisms (SNPs) and 357,639 insertion–deletions. Based on the principal component analysis and population structure analysis of these data, the WRC can be classified into three major groups. We applied TASUKE, a multiple genome browser to visualize the different WRC genome sequences, and classified haplotype groups of genes affecting seed characteristics and heading date. TASUKE thus provides access to WRC genotypes as a tool for reverse genetics. We examined the suitability of the compact WRC population for genome-wide association studies (GWASs). Heading date, affected by a large number of quantitative trait loci (QTLs), was not associated with known genes, but several seed-related phenotypes were associated with known genes. Thus, for QTLs of strong effect, the compact WRC performed well in GWAS. This information enables us to understand genetic diversity in 37,000 rice accessions maintained in the Genebank and to find genes associated with different phenotypes.The sequence data have been deposited in DNA Data Bank of Japan Sequence Read Archive (DRA) (Supplementary Table S1).

Rice policy in a transitional economy: balancing the social and political objectives

Rice is an important component on the global food security agenda. However, prevailing economic analysis suggests that rice policy globally is often damaging and not economically efficient, rendering food security as a goal highly vulnerable to volatility in the world rice market. This paper explores the case of Vietnam’s rice policy as a key rice exporter, a country that has developed highly distinctive policy settings to manage the inherent tensions between ‘socialist’ policy legacies and ‘market-based’ objectives during an economy-wide liberalisation process. In open economy political terms, our case study facilitates the exploration of two key issues. First, how well the OECD-centric concept of agricultural policy exceptionalism works in a developing country context. Second, how the policy may succeed politically even in the face of what appear to be severe political constraints from external economic pressures. The paper develops a narrative of the political economy of rice policy in Vietnam during the Renovation (Doi Moi) Period from 1986 to the present. We find, first, that the policy trajectory in Vietnam’s rice sector runs counter to recent claims about post-exceptionalism in agriculture; that is, rice policy has resisted pressures to comply fully with market rules despite Vietnam’s accession to the World Trade Organization. Second, the interaction of economic liberalisation processes and the ruling Communist Party’s political survival strategy results in policy settings that fail standards of policy coherence and are often economically inefficient, although the survival strategy itself remains stable and reform-resistant over time.

Market integration and spatial price transmission in grain markets of Turkey

ABSTRACTThis paper examines whether the grain market of Turkey is cointegrated with the world grain market. Using an error correction model, we analyse the response of producer prices of wheat, barley, maize, soybean and rice to changes in world market prices. Results show that the rice market of Turkey is not cointegrated with the world rice market, while the other commodity markets are weakly cointegrated. Results also show that pass-through of changes in the world prices to the domestic prices is relatively low both in the short run and in the long run, and that adjustment to the new equilibrium following a shock is slow. Government intervention policies both at the border and as domestic price supports seem to be underlying causes of the weak cointegration. Fewer protectionist policies and lower levels of government intervention are necessary to increase the domestic grain market integration with the international grain market.

Challenges and Opportunities Associated with Drying Rough Rice in Fluidized Bed Dryers: A Review

Highlights Fluidized bed drying of rice has several advantages that outweigh its disadvantages. Increasing the drying temperature above 60°C could reduce rice quality. Research related to energy and exergy efficiencies in fluidized bed dryers of rice is needed. Abstract. Rice (Oryza sativa L.) is a staple food for more than half the world’s population. World rice production reached approximately 740 million metric tons (MMT) in 2018 due to the ever-increasing demand driven by population and economic growth. Rice producers face challenges in meeting this demand, especially in developing countries where rice is prone to spoilage if the moisture content is not reduced to a safe level shortly after harvest. Rice producers, particularly in developing countries, typically use conventional drying methods, i.e., sun drying and natural air drying. These methods are time-consuming and environmentally dependent. On the other hand, fluidized bed drying, which is a well established technology, could provide rice producers with an effective drying technique that is quick, practical, affordable, and portable. Several innovative designs for fluidized bed dryers have been developed that could be installed on-farm or off-farm at a reasonable cost. Some studies have mentioned that the main advantage of fluidized bed drying is the increase in drying rate and the reduction of rice spoilage after harvest. Conversely, other studies have raised alarms regarding low rice quality, which is seen as a significant flaw of fluidized bed drying. Due to this lack of consensus, there is a great need to review this drying technology objectively. Therefore, this review article explores fluidized bed drying and details its advantages and disadvantages related to rice drying. It also sheds light on the effects of the operating parameters involved in fluidized bed drying, i.e., rice moisture content, drying temperature, airflow rate, air velocity, drying duration, and tempering duration, on dryer performance and rice quality. Several fluidized bed numerical models are also reviewed and evaluated. Additionally, this review explores the energy and exergy efficiencies of fluidized bed dryers and suggests opportunities for research associated with fluidized bed drying of rice. Keywords: Energy, Exergy, Fluidized bed drying, Fluidized bed modeling, Moisture content, Rice quality, Rough rice, Tempering.

Evaluation of major rice cultivars for resistance to bacterial seedling rot caused by Burkholderia glumae and identification of Japanese standard cultivars for resistance assessments.

Burkholderia glumae causes bacterial seedling rot (BSR) and bacterial grain rot (BGR) in rice (Oryza sativa), both of which are important diseases in Japan. We previously evaluated major Japanese cultivars for BGR resistance and selected standard cultivars for resistance assessments. Here, we assessed the BSR occurrence rate in cultivars from the World Rice Collection (WRC) and other sources and found wide variation in resistance. Next, we evaluated major Japanese cultivars for BSR resistance and found that two Japanese landraces, ‘Kujuu’ and ‘Aikoku’, showed “strong” resistance; most others were categorized as “medium” or “medium to weak”. We previously developed a near-isogenic line (RBG1-NIL) by introducing the genomic region containing RBG1, a quantitative trait locus (QTL) for BSR resistance, from ‘Nona Bokra’ (indica) into ‘Koshihikari’ (temperate japonica). The resistance level of RBG1-NIL was “strong”, indicating the effectiveness of RBG1 against BSR. The correlation between BSR and BGR resistance scores was low, indicating that it is necessary to introduce QTLs for resistance from different sources to develop cultivars resistant to both BSR and BGR. On the basis of the screening results, we selected standard cultivars for BSR resistance to cover a range of resistance levels.

Mapping of the world rice research: A bibliometric analysis of top papers during 2008–2018

Based on the Essential Science Indicators database, this study analyzed 1225 top papers of rice research from 2008 to 2018, which include 1219 highly cited papers and 24 hot papers in the field. VOSviewer software was used to visually analyze documents. Results showed that 5100 authors belonging to 1428 organizations from 84 countries/territories authored the papers in 277 core journals. There are 10 papers that have received more than 1000 citations. Top five core journals are Plant Cell, Plant Physiology, PNAS, Food Chemistry and Journal of Experimental Botany. Top 5 countries and regions were China, USA, Japan, England and Germany. Top 5 organizations identified are Chinese Academy of Science, Chinese Academy of Agricultural Science, Huazhong Agricultual University, Nanjing Agricultural University and Zhejiang Univ.