No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Where rice pests and diseases do the most damage.
... Direktorat Perlindungan Tanaman Pangan (2015) melaporkan bahwa 445.001 ha sawah terserang OPT dan 2.424 ha mengalami gagal panen. OPT menyebabkan kehilangan hasil antara 24 41% (Savary dan Willocquet 2000;Sparks et al. 2012) atau rata-rata 37% (Sparks et al. 2012). ...
... Direktorat Perlindungan Tanaman Pangan (2015) melaporkan bahwa 445.001 ha sawah terserang OPT dan 2.424 ha mengalami gagal panen. OPT menyebabkan kehilangan hasil antara 24 41% (Savary dan Willocquet 2000;Sparks et al. 2012) atau rata-rata 37% (Sparks et al. 2012). ...
ABSTRAK Varietas unggul memberikan kontribusi nyata terhadap peningkatan produksi padi. Sumbangan penggunaan varietas unggul terhadap peningkatan produksi padi nasional mencapai 56%, sementara interaksi antara air irigasi, varietas unggul, dan pemupukan terhadap laju kenaikan produksi padi memberikan kontribusi hingga 75%. Penggunaan varietas unggul juga berkontribusi terhadap penurunan penggunaan pestisida. Namun, penggunaan varietas unggul di tingkat petani masih rendah. Beberapa faktor yang menghambat pengembangan varietas unggul ialah anggapan bahwa keunggulan varietas baru tidak sebanding dengan varietas yang ada, industri benih belum berminat mengembangkan varietas unggul, dan terbatasnya benih sumber untuk perbanyakan benih secara komersial. Tingkat komersialisasi varietas unggul dipengaruhi oleh produktivitas, kesesuaian mutu produk dengan selera konsumen, ketahanan terhadap hama dan penyakit, serta harga jual. Untuk mendukung percepatan adopsi varietas unggul padi, perlu kebijakan dalam bentuk peraturan daerah peningkatan produksi padi, jaminan sumber permodalan, penyediaan input terutama benih sumber, jaminan pemasaran dan harga jual gabah, kemitraan yang harmonis antarpemangku kepentingan, penguatan yang menarik hubungan dengan sumber informasi teknologi dan pasar output, reformasi, reorientasi dan revitalisasi kelembagaan petani, penguatan kelembagaan penyuluhan, serta pendekatan kepada tokoh masyarakat. ABSTRACT Improved varieties contribute significantly to the national rice production. Productivity improvement of improved varieties may deliver about 56% to the growth rate of national rice production, while the interaction between irrigation water, high yielding varieties and fertilizer contribute up to 75%. Improved varieties also assist in lessening the usage of pesticides. However, the use of improved varieties at farmers is limited. Some factors that led to the delaying development of improved varieties are its advantages are not comparable with existing varieties, the seed industry is not interested in developing improved varieties, and limited supply of seed resource for commercial seed production. Commercialization of improved varieties will be influenced by its superiority in terms of productivity, quality conformity with consumer needs, resistance to pests and diseases, and selling price. Some efforts are inquired to support acceleration of the adoption of improved varieties of rice, namely a touch of local government in terms of policy on local regulations to increase rice production, assurance to capital resources, assurance to input supply especially seed resources, marketing and attractive selling price, harmonious partnership between stakeholders, boost relationships with technology resources and market networks, farmers institutional reorientation and revitalization, strengthening of agricultural extension, as well as approach with community leaders.
... International Rice Research Institute (IRRI) reported that 37% of production loss occurred due to pests and diseases (Sparks & Castilla, 2012), and 5% of losses were due to overripe in the field (Deutsch et al., 2018). Injury to plants, such as broken and dead stems and branches, and leaves wounds, often increase losses and reduce production (Cerda et al., 2016). ...
Remote sensing based crop growth monitoring during an entire growing period is critical for crop production. Monitoring rice crop condition during growing season and yield prediction can enable better farm management and finally help increase yield. In this study, we proposed a UAV based image acquisition and analysis system to monitor rice growth during a whole growing season and measure yield in the field from the transplant stage to the harvest stage. In the transplant stage, we proposed the Faster-RCNN algorithm to recognize rice plants and count them in the field image. A hierarchical clustering and Hough transform based algorithm was adopted to analyze the distance between plants and distance between rows, missed plant position, and missed plant rate. The proposed method showed high potential in recognizing and counting the rice plants in orthomosaic images. The average Precision, Recall, and F1 score value was found between 0.95 and 0.99. The R2 value between ground truth and true positive for counting rice plants was found to be 0.96 with the RMSE of 24.25. The average distance between the plant rows and the average distance between the plants were found 28.8 cm with a standard deviation of 0.906 cm and 19.2 cm with a standard deviation of 2.74 cm, respectively. The GSD method was applied to estimate the GPS positions in orthomosaic images. The GPS information was used to monitor plants individually. In the growth stage, we proposed a point cloud based method to estimate the height and volume of rice plants. Equidistance layering was formed in the point cloud and the layers were converted into polygons using an improved convexhull method. The proposed method showed a good performance to estimate height and volume. The R2 values for height and volume measurement between actual and estimated values were 0.93 and 0.73, respectively. We proposed the K-means clustering with Lab color space transformation (KCL) and the K-means clustering and a graph-cut algorithm (KCG) to estimate rice yield in the harvest stage. Rice grains were segmented from the orthomosaic images using these methods and then the rice yield could be estimated. The KCG method proved better than the KCL method in grain area estimation with a lower average relative error of 14.37% than that of the KCL method. The KCG method also estimated the yield from different growing stages. The findings showed that the grain segmentation based on UAV images is likely reliable and easy to estimate yield. We also applied our methods to monitor individual rice crops in the field by projecting the GPS information. We estimated height and yield for the individual plant over the growing period. GPS based single plant monitoring system can contribute to increase the efficiency of crop management and finally productivity. The study provided the feasibility of UAV based monitoring of rice crop during a whole growing season. The systems and methods developed in this study can be applied to monitor other crops during a whole cultivation year.
... Rice has become one of the most important staple crops, feeding over half of the world's population (Cheng et al. 2013a). Annually, up to 37% of rice yield is lost due to diseases and arthropod pests on average (Sparks et al. 2012). Among them, blast, BLB, and BPH are the three main biotic stresses (Ji et al. 2016). ...
In the past century, there have been great achievements in identifying resistance (R) genes and quantitative trait loci (QTLs) as well as revealing the corresponding molecular mechanisms for resistance in rice to major diseases and insect pests. The introgression of R genes to develop resistant rice cultivars has become the most effective and eco-friendly method to control pathogens/insects at present. However, little attention has been paid to durable and broad-spectrum resistance, which determines the real applicability of R genes. Here, we summarize all the R genes and QTLs conferring durable and broad-spectrum resistance in rice to fungal blast, bacterial leaf blight (BLB), and the brown planthopper (BPH) in molecular breeding. We discuss the molecular mechanisms and feasible methods of improving durable and broad-spectrum resistance to blast, BLB, and BPH. We will particularly focus on pyramiding multiple R genes or QTLs as the most useful method to improve durability and broaden the disease/insect spectrum in practical breeding regardless of its uncertainty. We believe that this review provides useful information for scientists and breeders in rice breeding for multiple stress resistance in the future.
... 16,17 The pest insects also damaged the yield of rice. 18,19 The yield of jute has been increased by the application of 100% and 150% NPK 20 and by addition of different organic fertilizer. 21 The second pre-dominant crop of West Bengal is oilseeds and contributes about 18 % of the total net sown area. ...
The crops were cultivated in three distinct seasons of the Kaliyaganj C.D. Block in West Bengal. Present study was conducted on seven major crops (aman rice, boro rice, jute, maize, wheat, mustard and lentil) of the study area. The study was conducted during 2019 to 2020 cropping seasons. The objectives were to find out the impact of chemical fertilizer, organic fertilizer and pesticide use on yield and productivity of these crops. The correlation and regression analysis were used to access the impact of three intermediate inputs (chemical fertilizer, organic fertilizer and pesticide) on the crop productivity. Student ‘t’ test was used for testing the significance of the correlation. The study was also undertaken to work out the relative economics of the crops by analyzing the input and output costs. For this above purpose, the input and output data were collected from 120 sample plots (within 18 villages) of the study area. After all, the results suggested a clear role of fertilizer and pesticide use on the crop productivity and showed the impact of pest attack on the crops.
... According to IRRI (year) rice pests and diseases caused around 37% of yield losses in rice, whereas in the most severe condition, yield losses due to fungal disease can reach 80% (Godfray et al., 2016). However, depending on the production environment, these yield losses can vary between 24% -41% (Sparks et al., 2012). Weeds may become alternative host habitats to disease-causing pathogens (Seneviratne and Jeyanandarajah, 2004). ...
High-input, modern agriculture uses large amounts of energy, water, fertilizers, and pesticides to produce high crop yields. One of the major bottlenecks of the modern agriculture in the tropics is substantial yield losses due to fungal diseases including rice blast, leaf spots and leaf scald. The aim of this study was to compare the incidence of fungal diseases in judicious nutrient management systems, including organic, integrated, and conventional, under different weed categories during dry season (May to September 2020) and wet season (November 2020 to March 2021). Rice disease incidence were collected for both seasons from 48-84 days after sowing. Additionally, disease incidences on grasses and sedges weeds were also calculated. Brown spot, narrow brown leaf spot, leaf scald, and rice blast incidences were substantial in wet season, while the disease incidences during dry season in 2020 were negligible. The disease incidences were significantly higher (P<0.05) in organic and conventional input systems compared to the integrated input system. Disease incidences of brown spot and leaf scald were found in the dry season. Higher disease incidences were recorded in the wet season than in the dry season. The incidences of the brown spot were higher on sedges than in grasses and vice versa were observed for narrow brown leaf spot disease. Leaf scald incidences were positively correlated with the significant nitrogen status of the rice crop. Disease incidence was low in integrated input system compared to conventional and organic input systems, while weeds were reported as alternative hosts. It can be concluded that the integrated nutrient management with recommended dosage of nitrogen application with proper weed management can lead to low disease incidents, hence is ecologically more sustainable.
... However, rice productivity in India has been stagnant in recent years (Kumar et al., 2021). This production shortfall, early stage of infection (Sparks et al., 2012). Moreover, the symptoms of different diseases are frequently indistinguishable as they look identical. ...
... Like other crop plants, rice is susceptible to various diseases sustained by microorganisms, including viruses, bacteria, and fungi, which cause huge economic losses to farmers [2]. A study published by the International Rice Research Institute (IRRI) reported that, on average, farmers lose 37% of their rice production due to diseases and pests and that these losses can range between 24% and 41%, depending on the production situation [3]. Fungal infections of rice can also pose a significant human health risk due to mycotoxin contamination, especially in geographical areas where rice is a staple food [4]. ...
Cultivated rice is a staple food for more than half of the world’s population, providing approximately 20% of the world’s food energy needs. A broad spectrum of pathogenic microorganisms causes rice diseases leading to huge yield losses worldwide. Wild and cultivated rice species are known to possess a wide variety of antimicrobial secondary metabolites, known as phytoalexins, which are part of their active defense mechanisms. These compounds are biosynthesized transiently by rice in response to pathogens and certain abiotic stresses. Rice phytoalexins have been intensively studied for over half a century, both for their biological role and their potential application in agronomic and pharmaceutical fields. In recent decades, the growing interest of the research community, combined with advances in chemical, biological, and biomolecular investigation methods, has led to a notable acceleration in the growth of knowledge on rice phytoalexins. This review provides an overview of the knowledge gained in recent decades on the diversity, distribution, biosynthesis, chemical synthesis, and bioactivity of rice phytoalexins, with particular attention to the most recent advances in this research field.
... The overall increase in number of economically important pests within a span of 52 years rings a bell of caution for analysing and identifying the factors responsible for such increase and also to bridge the gaps of management system so that the varieties can yield to their maximum potential. On an average, farmers loose 37 % of their rice yield to pests and diseases, and these losses can range between 24 and 41 % depending on the production situation (Sparks et al. 2012). At the national level, stem borers account for 30% of the losses while plant hoppers, gall midge, leaf folder and other pests are responsible for about 20%, 15%, 10% and 25%, respectively (Krishnaiah and Varma 2013). ...
Crop Protection Division at NRRI is emphasizing on host plant resistance research using apt screening methodology for different insect pest and diseases. Studies on crop loss estimation, ecology, epidemiology, toxicology and integrated pest management (IPM) are integral components of investigation of the division since its inception. Methodology for large scale screening like uniform blast nursery (UBN) developed by the Division has been adopted worldwide. More than 1,25,000 genotypes were screened to find out novel sources of resistance against rice pests. Scientists have identified resistant genotypes against bacterial leaf blight (BLB) and brown plant hopper (BPH) which were used to find out novel genes. Novel quantitative trait loci (qBph4.3 and qBph4.4) associated with BPH resistance in the rice landrace “Salkathi” has been identified. Research on yield loss estimation and ecology of pests is being carried out here to understand the dynamics of rice pests. The scientists are also working on evaluation of different pesticides, use of biocontrol agents
and indigenous technical knowledge (ITK) to offer options to farmers for the best pest management options. Developed IPM technologies are well accepted by the farmers. The contribution of the division in rice crop protection science is reflected through the quality publications by the scientists. The division is adopting new tools and techniques such as genomics, proteomics, genome editing, nanotechnology and space technology to provide more accurate and precise options to the farmers to tackle the complex and emerging pest situations in rice production systems.
... Rice is susceptible to several diseases caused by bacteria, viruses and fungi [1]. Farmers lose an average of 37% of their rice yields to pests and diseases, with losses ranging from 24% to 41% depending on the production circumstances [2]. Two important rice diseases caused by bacteria, bacterial leaf blight (BLB) and bacterial leaf streak (BLS), are common in tropical and temperate regions [3]. ...
Rice is one of the most important food crops in the world and is of vital importance to many countries. Various diseases caused by fungi, bacteria and viruses constantly threaten rice plants and cause yield losses. Bacterial leaf streak disease (BLS) caused by Xanthomonas oryzae pv. oryzicola (Xoc) is one of the most devastating rice diseases. However, most modern rice varieties are susceptible to BLS. In this study, we applied the QTL-seq approach using an F2 population derived from the cross between IR62266 and Homcholasit (HSC) to rapidly identify the quantitative trait loci (QTL) that confers resistance to BLS caused by a Thai Xoc isolate, SP7-5. The results showed that a single genomic region at the beginning of chromosome 5 was highly associated with resistance to BLS. The gene xa5 was considered a potential candidate gene in this region since most associated single nucleotide polymorphisms (SNPs) were within this gene. A Kompetitive Allele-Specific PCR (KASP) marker was developed based on two consecutive functional SNPs in xa5 and validated in six F2 populations inoculated with another Thai Xoc isolate, 2NY2-2. The phenotypic variance explained by this marker (PVE) ranged from 59.04% to 70.84% in the six populations. These findings indicate that xa5 is a viable candidate gene for BLS resistance and may help in breeding programs for BLS resistance.
... Annually 25 to 40% of rice is lost to pests and diseases (Sparks et al. 2012). Fungal blast caused by Mangaporthe oryzae and bacterial leaf blight caused by Xanthomonas oryzae pv oryzae (Xoo) severely reduce rice yield. ...
Key messageAn integrated research approach to ensure sustainable rice yield increase of a crop grown by 25% of the world’s farmers in 10% of cropland is essential for global food security.
AbstractRice, being a global staple crop, feeds about 56% of the world population and sustains 40% of the world’s poor. At ~ $200 billion, it also accounts for 13% of the annual crop value. With hunger and malnutrition rampant among the poor, rice research for development is unique in global food and nutrition security. A systems-based, sustainable increase in rice quantity and quality is imperative for environmental and biodiversity benefits. Upstream ‘discovery’ through biotechnology, midstream ‘development’ through breeding and agronomy, downstream ‘dissemination and deployment’ must be ‘demand-driven’ for ‘distinct socio-economic transformational impacts’. Local agro-ecology and livelihood nexus must drive the research agenda for targeted benefits. This necessitates sustained long-term investments by government, non-government and private sectors to secure the future food, nutrition, environment, prosperity and equity status.
... About 15.6% yield loss due to disease in India (Mondal et al., 2017). Rice yield loss due to pest and disease can range between 24% and 41% depending on the production situation (Sparks et al., 2012). ...
Rice blast (Magnaporthe oryzae) is one of the most devastating rice diseases which can lead a complete failure of the crop under severe infection. Development of durable blast resistant variety is the best option to control the disease. A better option for such attempt is the use of native blast resistant germplasm. Therefore, experiment was conducted to explore the phenotypic reaction of native rice germplasm for selection of resistant source. Further, identification of major blast resistance gene(s) exist in these germplasm were detected using molecular markers and analyze the population structure on the basis of blast resistance genes. Forty-four native germplasm, collected from Bangladesh Rice Research Institute (BRRI) Genebank, were tested for phenotypic reaction in uniform blast nursery (UBN) of BRRI against blast disease during T. Aman 2018 and Boro 2018-19 season. Molecular screening was performed at the molecular laboratory of Plant Pathology Division, BRRI. Among the tested genotypes, Acc. 3080 having Pita-2 gene was resistant (disease score 1). While nine accessions viz. Acc. 3058, Acc. 3060, Acc. 3068, Acc. 3071, Acc. 3073, Acc. 3975, Acc. 3076, Acc. 3083 and Acc.3085 were found moderately resistant (disease score 2-3). Accessions 3058 and 3075 having 6 genes (Pit, Pib, Pi9, Pi40, Pita-2 and Pita/Pita-2) with disease score 2. Germplasm possessing blast resistance genes varied from 0 to 6 and gene frequency of resistance genes ranged from 2.27% to 59.09% among the tested germplasm. PIC values of eight markers varied from 0.04 to 0.37 at an average 0.29. Out of eight markers one marker Pita3 was found to be significantly associated (p=0.003, R2=0.19) with blast disease. Population structure analysis based on genotypic and phenotypic against blast disease divided the germplasm into two distinct subgroups. Acc. 3076 having Pit, Pi40 and Pita/Pita-2 genes with disease score 2 was detected in a separate group from other moderately resistant germplasm in cluster analysis. Therefore, Acc 3058, Acc 3075, Acc. 3076 and Acc. 3080 could be used for the development of durable blast resistant variety.
... Rice is attacked by plethora of diseases and yield loss due to pests and diseases ranges between 24 and 41 % ( Sparks et al. 2012). There were exciting progresses made through molecular techniques to reduce the yield loss and maintain the grain quality of the crop. ...
Rice was introduced in 1970s and has since been cultivated in different parts of the country at limited scale. Traditional method of pre-harvest operations such as ploughing, planting, chemical application lead to tremendous magnitude of drudgery and reduced yield. In order to address these pre-harvest problems, introduction and promotion of appropriate technologies is essential. Hence the present review describes an overview of the main rice pre-harvest operations traditionally used by in Ethiopian farmers and highlights attempts made to introduce appropriate pre-harvest technologies for reducing drudgery and improving efficiencies in rice production. Generally, all production and post-production operations are done following the local knowledge, practice and traditional tools and implements used for other grain crops. Delayed ploughing, planting due to lack of modern technologies and access to efficient land preparation, weeding and seeding implements are serious problems. With the introduction of appropriate pre-harvest technologies such as power tillers, seeders and manual rotary weeders significant drudgery reductions and yield increment were achieved. For wider adoption of these technologies, access to technical know-how, appropriate equipment to their circumstances through training and technology demonstrations at farm level is essential.
... Rice is attacked by plethora of diseases and yield loss due to pests and diseases ranges between 24 and 41 % (Sparks et al. 2012). There were exciting progresses made through molecular techniques to reduce the yield loss and maintain the grain quality of the crop. ...
... The overall increase in number of economically important pests within a span of 52 years rings a bell of caution for analysing and identifying the factors responsible for such increase and also to bridge the gaps of management system so that the varieties can yield to their maximum potential. On an average, farmers loose 37 % of their rice yield to pests and diseases, and these losses can range between 24 and 41 % depending on the production situation ( Sparks et al. 2012). At the national level, stem borers account for 30% of the losses while plant hoppers, gall midge, leaf folder and other pests are responsible for about 20%, 15%, 10% and 25%, respectively (Krishnaiah and Varma 2013). ...
... It is a major constraint limiting the optimal production of crops included rice. Many studies have reported yield loss due to rice diseases in different intensity, from light to very severe yield losses (Sparks et al., 2012;Barnwal et al., 2013;Kihoro et al., 2013). As an example, the estimated annual loss of rice only due to blast disease was enough to feed 60 million people for one year (Pennisi, 2010). ...
Plant diseases are major obstacles in achieving optimal yields in crop plants including rice. The use of diseases-resistant varieties is one of the most practical and economical approaches to overcome this problem. The local rice populations (landraces) are
important genetic resources containing useful genes for many important traits, including disease resistance characters. The objectives of this study were to evaluate the responses of East and North Kalimantan local upland rice population against rice
diseases and to select the local cultivars having resistance against the diseases. Disease resistance was evaluated using natural
disease epidemic selection. A 109 Indonesian local upland rice cultivars were grown in two different growing conditions, in screen
house and field trial. Diseases were characterized by their symptoms on the plants and the corresponding causing agents. Disease
intensity was scored by observing the percentage of disease symptoms on the plants in the field trial. The results showed that
bacterial blight (Xanthomonas oryzae) was the most frequent disease infecting East and North Kalimantan local upland rice
population followed by narrow brown spot, brown spot, sheath blight and black kernel. A specific interaction between the host and
pathogen was observed in this study. Some genotypes were resistant, and some others are susceptible to the particular disease.
However, most of the local rice cultivars were grouped into resistant and moderately resistant genotypes. The East and North
Kalimantan local upland rice population characterized in this study, contained genes that confer resistance to one or more
pathogens, which could be further used as a source of vertical or horizontal resistance genes in rice breeding programs.
... It is a major constraint limiting the optimal production of crops included rice. Many studies have reported yield loss due to rice diseases in different intensity, from light to very severe yield losses (Sparks et al., 2012;Barnwal et al., 2013;Kihoro et al., 2013). As an example, the estimated annual loss of rice only due to blast disease was enough to feed 60 million people for one year (Pennisi, 2010). ...
... It is a major constraint limiting the optimal production of crops included rice. Many studies have reported yield loss due to rice diseases in different intensity, from light to very severe yield losses (Sparks et al., 2012;Barnwal et al., 2013;Kihoro et al., 2013). As an example, the estimated annual loss of rice only due to blast disease was enough to feed 60 million people for one year (Pennisi, 2010). ...
Plant diseases are major obstacles in achieving optimal yields in crop plants including rice. The use of diseases-resistant varieties is one of the most practical and economical approaches to overcome this problem. The local rice populations (landraces) are important genetic resources containing useful genes for many important traits, including disease resistance characters. The objectives of this study were to evaluate the responses of East and North Kalimantan local upland rice population against rice diseases and to select the local cultivars having resistance against the diseases. Disease resistance was evaluated using natural disease epidemic selection. A 109 Indonesian local upland rice cultivars were grown in two different growing conditions, in screen house and field trial. Diseases were characterized by their symptoms on the plants and the corresponding causing agents. Disease intensity was scored by observing the percentage of disease symptoms on the plants in the field trial. The results showed that bacterial blight (Xanthomonas oryzae) was the most frequent disease infecting East and North Kalimantan local upland rice population followed by narrow brown spot, brown spot, sheath blight and black kernel. A specific interaction between the host and pathogen was observed in this study. Some genotypes were resistant, and some others are susceptible to the particular disease. However, most of the local rice cultivars were grouped into resistant and moderately resistant genotypes. The East and North Kalimantan local upland rice population characterized in this study, contained genes that confer resistance to one or more pathogens, which could be further used as a source of vertical or horizontal resistance genes in rice breeding programs.
... The larger spots have a dark brown margin and a light reddish-brown or gray center with a gold halo (Plate 1). The pathogen also attacks the coleoptiles, branches of the panicle, glumes and grains (Sparks et al., 2012). The fungus causes brown, circular to oval spots on the coleoptile leaves of the seedlings (Plate 2). ...
An attempt was made to study the role of environmental factors on the development of rice brown spot under the agro-ecological condition of red and lateritic belt of West Bengal during the winter season of 2013-2014. The severity of brown spot was increased at a faster rate during the initial period and reached at a maximum level of 5.18% PIPDI (periodical increment in percentage disease index) and 12.7% CIPDI (cumulative increment in percentage disease index) during 3 rd and 4 th week of September in both of the season. Thereafter, disease was progressed at a lower rate and came down at 0.35% PIPDI during 1st week of November. When maximum average temperature ranged from 32.6 to 34.21°C, minimum average temperature maintained between 23.61°C to 26.18°C, average relative humidity varied between 80.71 to 85.81%, having moderate rainfall, average sunshine of 4.63 to 6.16 kmh-1 and moderate wind speed from 1.0 to 1.57 kmh-1 persist in rice field maximum periodical increment in PDI might be expected. From the R 2 value it can be stated that, these six meteorological factors are responsible up to the extent of 85.2% for the development of the disease (cumulative). Similarly, meteorological factors that were regressed on PIPDI could explain the variation up to the extent 53.7%. The present investigation highlighted the actual severity level of brown spot of winter rice. It may also help the farmers for predicting the actual time of disease management and for decision making.
... It is a major constraint limiting the optimal production of crops included rice. Many studies have reported yield loss due to rice diseases in different intensity, from light to very severe yield losses (Sparks et al., 2012;Barnwal et al., 2013;Kihoro et al., 2013). As an example, the estimated annual loss of rice only due to blast disease was enough to feed 60 million people for one year (Pennisi, 2010). ...
Plant diseases are major obstacles in achieving optimal yields in crop plants including rice. The use of diseases-resistant varieties is one of the most practical and economical approaches to overcome this problem. The local rice populations (landraces) are important genetic resources containing useful genes for many important traits, including disease resistance characters. The objectives of this study were to evaluate the responses of East and North Kalimantan local upland rice population against rice diseases and to select the local cultivars having resistance against the diseases. Disease resistance was evaluated using natural disease epidemic selection. A 109 Indonesian local upland rice cultivars were grown in two different growing conditions, in screen house and field trial. Diseases were characterized by their symptoms on the plants and the corresponding causing agents. Disease intensity was scored by observing the percentage of disease symptoms on the plants in the field trial. The results showed that bacterial blight (Xanthomonas oryzae) was the most frequent disease infecting East and North Kalimantan local upland rice population followed by narrow brown spot, brown spot, sheath blight and black kernel. A specific interaction between the host and pathogen was observed in this study. Some genotypes were resistant, and some others are susceptible to the particular disease. However, most of the local rice cultivars were grouped into resistant and moderately resistant genotypes. The East and North Kalimantan local upland rice population characterized in this study, contained genes that confer resistance to one or more pathogens, which could be further used as a source of vertical or horizontal resistance genes in rice breeding programs.
... On average, farmers lose 37 % of their rice yield to pests and diseases, and these losses can range between 24 and 41 % depending on the production situation (Sparks et al. 2012). While many of these can be handled with management practices, often it is not the viable option due to financial and educational status of the farmers and unavailability of the pesticides. ...
Rice is the staple food for over half of the global population and a major calorie source. It is mainly grown in the developing world. Green revolution contributed significantly toward self-sufficiency of developing countries in rice production. Demand for rice continues to increase due to the ever increasing rice consumer base. However, the present rate of rice production has slowed down in comparison to previous decades due to various biotic and abiotic stresses. Numerous biotechnological initiatives and strategies have been undertaken aiming for an enhanced rice production. Broadly, this included tissue culture, marker-assisted breeding, and genetic engineering. The major genetic gain from biotechnology toward rice production is contributed from molecular breeding. A number of quantitative trait loci (QTLs) and genes have been identified and used in varietal improvement. Genes conferring tolerance to submergence stress, salt stress, drought, blast, and blight diseases have already been deployed to rice varietal improvement. Transgenic approach is mainly used for research, though efforts are being made for its commercial use. Bottlenecks in biosafety regulations need to get resolved for making this technology impactful. In addition to the direct application in varietal improvement, biotechnological tools are used in enhancing genetic understanding of complex traits which in turn plays a crucial role in strategizing the breeding programs. Further efforts are required for handling bottlenecks of breeding, particularly in resolving the complexity of agronomically important traits such as grain yield. In the post-green revolution era, biotechnology has played a significant role in fast-track rice varietal improvement, thereby grain production; however, there is a long way to go.
... Annually, 37% of rice is lost, with significant losses from brown planthopper feeding and disease transmission (Sparks et al. 2012). Reduction in losses through best management practices, increasing farmer education and support, and incorporating genetic resistance into rice cultivars is key to feeding the world's growing population and eradicating poverty. ...
... Annually, 37% of rice is lost, with significant losses from brown planthopper feeding and disease transmission (Sparks et al. 2012). Reduction in losses through best management practices, increasing farmer education and support, and incorporating genetic resistance into rice cultivars is key to feeding the world's growing population and eradicating poverty. ...
... A large number of pathogenic microorganisms cause important diseases in rice. (IRRI) showed that, on average, farmers lose 37% of their rice yield due to diseases and pests [3]. Rice research, therefore, can have a major beneficial impact on human wellbeing, and the improvement of disease resistance in rice is a key research goal. ...
Rice is one of the most important food crops, feeding about half population in the world. Rice pathogens cause enormous damage to rice production worldwide. In plant immunity research, considerable progress has recently been made in our understanding of the molecular mechanisms underlying microbe-associated molecular pattern (MAMP)-triggered immunity. Using genome sequencing and molecular techniques, a number of new MAMPs and their receptors have been identified in the past two decades. Notably, the mechanisms for chitin perception via the lysine motif (LysM) domain-containing receptor OsCERK1, as well as the mechanisms for bacterial MAMP (e.g. flg22, elf18) perception via the leucine-rich repeat (LRR) domain-containing receptors FLS2 and EFR, have been clarified in rice and Arabidopsis, respectively. In chitin signaling in rice, two direct substrates of OsCERK1, Rac/ROP GTPase guanine nucleotide exchange factor OsRacGEF1 and receptor-like cytoplasmic kinase OsRLCK185, have been identified as components of the OsCERK1 complex and are rapidly phosphorylated by OsCERK1 in response to chitin. Interestingly, OsCERK1 also participates in symbiosis with arbuscular mycorrhizal fungi (AMF) in rice and plays a role in the recognition of short-chitin molecules (CO4/5), which are symbiotic signatures included in AMF germinated spore exudates and induced by synthetic strigolactone. Thus, OsCERK1 contributes to both immunity and symbiotic responses. In this review, we describe recent studies on pathways involved in rice immunity and symbiotic signaling triggered by interactions with microorganisms. In addition, we describe recent advances in genetic engineering by using plant immune receptors and symbiotic microorganisms to enhance disease resistance of rice.
In the era of climate change, continuous breeding efforts are required to dissect and detect genomic regions responsible for stress resilience and achieve a rapid genetic gain in rice. Bi-parental linkage mapping significantly contributed to identifying major genomic regions associated with several agronomic and stress tolerance traits. However, many of the causative alleles responsible for biotic and abiotic stress resistance controlled by minor genes were unidentified in rice. The advancements in molecular marker and genome analysis technologies which evolved from cutting-edge research resulted in new breeding tools, viz. genome-wide association and prediction. The genome-wide association (GWAS) study utilizing LD mapping from diverse panels unravels several loci and alleles for resistance to various stresses in natural populations. Similarly, genomic selection (GS), the upgraded version of MAS, helps in selecting the genotypes based on genomic-estimated breeding values for target traits. The GS approach provides an opportunity to increase the genetic gain per unit time and cost for complex traits. Presently in rice improvement, GWAS and GS were successfully employed to identify causative alleles for resistance to various stresses and predict the genetically appropriate genotypes for resistance breeding in rice, respectively. These genetic tools are proved as the most promising approaches in rice improvement for stress resilience. The present book section summarized the updates and prospects on GWAS and GS in stress resistance rice breeding.KeywordsRice genomicsStress toleranceGWAS and GSGenomics-assisted breeding
Recent advancements in the field of Deep learning have helped in predicting and locating pests in agricultural field images accurately. A drawback of this approach is that it requires a large training dataset for each sample, which is not feasible. Since there is a wide variety of pests, collecting thousands of training images for each sample is impractical. To deal with this issue, a pest detection meta-learning technique based on Few-shot is proposed in this paper. In this work, pests from rice crops are considered for experiments. Two pest-image datasets: IP102 as a supported dataset to perform meta-learning and an image library for insects and pests known as the Indian Council of Agricultural Research-National Bureau of Agricultural Insect Resources (ICAR-NBAIR) are taken to perform Few-shot learning. In meta-learning phase, the proposed model is trained on a variety of pests, and hence the proposed system is capable of learning new categories of pests with very few training images.
Rice crop has been cultivated since very long to provide food for the humans as well as animals. Gene discovery and functional genomics of rice are being used for the study of the complete gene profiling of rice that can be further used for obtaining more sustainable transcripts for the rice. Main purpose of the whole biotechnological study of the rice is to enhance the yield of this crop. For this, transgenic plants are being introduced that give abundant yield. Similarly, C4 plants marker-assisted breeding to get more number of grains per plant is also in use. Another approach to deal with the high demand of rice is to make them more resistant against the viral attacks, environmental hazards, and herbaceous as well as bacterial attack. Besides, the amount of nutritional quality of the rice crop is also a target of the study. This is also achieved by biotechnological approaches. Targeted genome editing technologies like TALENs and CRISPR/Cas system could be exploited for modifying defunct alleles of beneficial genes or to knock out unwanted genes in plants without any trace of transgene. Biotechnological instrumentation and practices provide a chance for creating novel variations for the rice breeders.KeywordsRiceYieldProductionImprovementTechnology
Finger millet is highly nutra-cereal crop having rich sources of fiber, calcium, and proteins. In India, crop is grown mainly as rainfed crop which is known as poor man’s crop. Till recently, very less genomic information is available, however which was filled with recent whole genome sequence of finger millet. The crop finger millet is widely adapted to harsh climatic conditions which are also a drought tolerant crop. Despite its well-known use as key cereal crop, mainly for deprived persons in the dry climatic areas, it is ignored in genetic enhancement programmes. Genomic studies revealed several significant QTLs for blast resistance, drought tolerance, and other quality parameters. The present chapter described in brief on the genomics improvement of finger millet for various biotic, abiotic and nutritional parameters. Comparative genomics also studied in brief in comparison with related crops like pearl millet and rice to identify the key homolog and orthologous genes. Genetic engineering approaches were mainly targeted for improvement of drought tolerance and blast resistance which are major factors in finger millet improvement. The present chapter gives a clear picture on various aspects of phylogeny, origin, genetics, molecular and genetic engineering approaches for finger millet genetic enhancement.
Among major cereal crops, rice plays an important role in global food security as well as to the economic and social stability. Considering the impacts of global warming on agriculture and alarming yield losses due to biotic and abiotic stresses as well as the effect of the climate change on the future insect-pest scenario, effective utilization of advanced tools and techniques of insect-disease biotype/pathotype monitoring and surveillance, identification of stable resistance sources, molecular plant pathology to understand the pathotype/biotype-gene interactions, molecular biology and modern genomics tools to assist crop breeding develop resistant/tolerant varieties shall help researchers find stable solutions. The losses caused by biotic stresses are comparatively high and impart 37–70% yield losses or complete crop failure in many cases. Keeping this in mind, the chapter discusses the importance of rice in global food security, major and emerging biotic stresses in rice, genetic resources of resistant/tolerant genes, map-based gene cloning, trait mapping and major QTLs’ identification, conventional and genomic assisted breeding strategies to develop multiple biotic stress resistant rice varieties. Further, the chapter emphasizes on the efforts including genetic engineering, gene editing and nanotechnological approaches in imparting stable resistance to biotic stresses. The chapter also discusses about various available bioinformatics tools and brief account on social, political and regulatory issues.
This new book Plant Genetic Resources and Climate Change contains 11 chapters summarizing perspectives on climatic change and how it might affect plant populations, and the expected impact on agriculture around the world. It presents some of the latest perspectives about how genetic resources can contribute to achieving food security under the challenge of a changing climate. It aims to highlight some key issues for plant genetic resources management, to demonstrate how perspectives have changed over two decades, and discuss some of the actual responses and developments.
ResearchGate has not been able to resolve any references for this publication.