Temporal and spatial progression of sheath blight in mega rice varieties of South Asia

2021 ◽  
Author(s):  
Jagjeet Singh Lore ◽  
Mandeep Singh Hunjan ◽  
Jyoti Jain ◽  
Sanjay Kumar ◽  
Pritpal Singh ◽  
...  
Keyword(s):  
South Asia ◽  
Sheath Blight ◽  
Rice Varieties ◽  
Temporal And Spatial

Identification of novel resistance source in traditional varieties against major diseases of rice

2020 ◽  
Vol 57 (2) ◽  
pp. 116-125
Author(s):  
BS Chethana ◽  
CA Deepak ◽  
MP Rajanna
Keyword(s):  
Large Scale ◽  
Crop Improvement ◽  
Durable Resistance ◽  
Sheath Blight ◽  
Brown Spot ◽  
Rice Varieties ◽  
Resistant Reaction ◽  
Resistant Varieties ◽  
Wide Range ◽  
Traditional Rice

Traditional rice varieties maintained and cultivated by farmers are the potential sources of resistant donors that can be used for breeding rice varieties with durable resistance. They possess traits potentially adaptable to a wide range of abiotic and biotic stresses. Characterization of these germplasm is essential in rice breeding varieties and provides valued information for developing new rice. In this study, a large-scale screening of 167 traditional rice varieties was carried out to identify resistance sources against blast, sheath blight and brown spot diseases of rice. The mean location severity index (LSI) of leaf blast, sheath blight and brown spot was 6.91,7.14 and 7.84, respectively. Among the varieties screened, five varieties viz., Malgudi sanna, Putta batta, Selamsanna, Sadaholga and Mysuru sanna showed resistant reaction against blast, while only one variety Putta batta showed resistant reaction against brown spot, none of the varieties showed resistant reaction against sheath blight. However, only one variety Bangara sanna-4 showed moderate resistance to the sheath blight disease. The identified resistant varieties can be used as potential source for breeding durable resistant varieties in the future crop improvement programmes.

Source apportionment of surface-level trace gases and particulate matter at three tropical coastal sites in India

2021 ◽  
Author(s):  
Abhishek Chhari ◽  
Vinay Kumar Dhadwal ◽  
Lokesh Kumar Sahu ◽  
Bomidi Lakshmi Madhavan ◽  
Trupti Das ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
South Asia ◽  
Mass Concentration ◽  
Trace Gases ◽  
Concentration Data ◽  
Gangetic Plain ◽  
Surface Mass ◽  
Temporal And Spatial ◽  
Significant Attention

<p>Over last two decades, South Asia has witnessed a rapid increase in population, industrialization, and energy demands. Consequently, 2-6 fold increase in the emission of particulate matter (PM) and trace gases were reported. Air pollution in South Asia has more adverse impact and is linked to nearly 1 million premature deaths and around 10 million tonnes of crop loss in a year. So, monitoring of trace gases and PM concentrations over urban centers has received significant attention among scientists, policymakers, health regulatory agencies, and the media. Particularly over the Indian region, this becomes significant, as the observation of trace gases and PM concentrations with fairly good temporal and spatial resolutions is limited. Concerns about air quality and transport pathways on a regional scale also place more stringent demand on observations and modeling effort. Quantifying the source contribution (regional emission due to various anthropogenic activities such as city traffic density vs. long-range transport due to meteorological influence) of trace gases and PM over different temporal and spatial scales has been receiving significant attention. In view of this, measurement of trace gases and PM in concurrence with meteorological variables (wind speed and direction) is of paramount importance.</p><p> </p><p>In this study, we have presented three-year surface measurements of TGs (O<sub>3</sub>, CO, NO<sub>x</sub>, SO<sub>2</sub> and NH<sub>3</sub>) and PMs (PM2.5 and PM10) at three coastal and urban sites, namely, Trivandrum (TVM, 8.5°N, 76.9°E, 5m AMSL), Chennai (CHN, 13.7°N, 80.2°E, 6.7m AMSL) and Bhubaneswar (BHB, 20.2°N, 85.8°E, 45m AMSL) located in India. -In addition to that Ozone Monitoring Instrument OMI’s, surface mass concentration data for SO<sub>2</sub> and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts data were also used to identify potential sources. The principal component analysis (PCA) and concentrated weighted trajectories (CWT) were applied to the dataset. The TGs and PM showed high values during winter and lower values in a monsoon at these sites. Both TGs and PM values were higher at BHB compared to those at TVM and CHN.  Surface O<sub>3</sub> at BHB was about 3 times higher than that at TVM and 2.2 times higher than that at CHN.  Interestingly, PCA suggests that the major concentrations of O<sub>3</sub>, PM10, and SO<sub>2</sub> at TVM and CHN were transported from different locations and not produced locally except for pre-monsoon at CHN, which was of local origin.  CWT analysis and OMI’s surface mass concentration data also suggest that the air quality at TVM could be influenced by heavy emissions transported from the Indo-Gangetic plain. The Merra-2 reanalysis well captured seasonal variations of TGs and PMs; and it overestimated surface O<sub>3</sub>, by a factor of about 2 to the measurement at the study sites.   </p>

scholarly journals Temporal and Spatial changes in Crop Patterns, Use of inputs and Hydrological Alteration in the case of Fogera floodplain, Ethiopia

2021 ◽  
Author(s):  
Mare Desta ◽  
Gete Zeleke ◽  
William. A. Payne ◽  
Wubneh Abebe
Keyword(s):  
Water Flow ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Temporal Trends ◽  
Primary Data ◽  
Nitrogen And Phosphorus ◽  
Rice Varieties ◽  
Hydrological Alteration ◽  
Spatial Changes ◽  
Temporal And Spatial

Abstract BauckgroundMore than half of the world's population consumes rice. The area under modern rice varieties has expanded, the use of chemical fertilizers and pesticides has increased in various countries. The hydrology of wetlands are also influenced by its chemical and physical characteristics. Hence, this research focused on temporal and spatial changes in crop patterns, input usage, and hydrological change in Fogera floodplain, with the objectives: a. what are the spatial and temporal trends in crops production pattern? b. What inputs have been used in the past and present to produce rice and other crops? c. What looks like the hydrological alteration of the area? The primary data was gathered through a questionnaire, focus group discussions, interviews, and field observations. Secondary data from Landsat imageries, SWAT input data, water flow, normalized difference vegetation index, and hydrological alteration of the site were collected. To analyze data, tables, graphs, and charts percentage, mean, and correlation were used. ResultNDVI results indicated that rice crop is growing while other variables are decreasing. artificial inputs are currently used but before the introduction of rice were not. Recession farming activities have also diminished wetland. Annual average water flow and rainfall have been trending upward. Flow of water with Nitrogen and Phosphorous has a negative correlation, with Pearson's values -0.069 and -0.072, respectively whereas the value 0.242 indicates that nitrogen and phosphorus have a positive relationship. ConclusionIn conclusion, these extended and intensification of farming practices have an impact on the biodiversity of fauna and flora of the area.

Elucidating Traditional Rice Varieties for Consilient Biotic and Abiotic Stress Management under Changing Climate with Landscape-Level Rice Biodiversity

Land ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1058
Author(s):  
L. Muralikrishnan ◽  
R. N. Padaria ◽  
Anchal Dass ◽  
Anil K. Choudhary ◽  
Bharat Kakade ◽  
...  
Keyword(s):  
South Asia ◽  
Climate Adaptation ◽  
Crop Improvement ◽  
Secondary Data ◽  
Climatic Conditions ◽  
Sample Survey ◽  
Biotic And Abiotic Stress ◽  
Rice Varieties ◽  
Therapeutic Benefits ◽  
Traditional Rice

Rice is grown under diverse agro-climatic conditions and crop management regimes across the globe. Emerging climatic-vulnerabilities and the mismatched farm practices are becoming major challenges for poor or declining rice productivity in potential rice growing regions, especially South Asia. In the biodiversity-rich landscapes of South Asia, many traditional rice varieties (TRVs) are known to exhibit resilience to climate change and climate adaptation besides their therapeutic benefits. Hence, a random sample survey of farmers (n=320), alongwith secondary data collection from non-governmental organizations/farmers’ organizations/farmers, led to documentation of the information on TRVs’ biodiversity in South Asia. The current study (2015-2019) explored and documented ~164 TRVs which may enhance the resilience to climatic-risks with improved yields besides their unique therapeutic benefits. A large number of TRVs have still not been registered by scientific organizations due to poor awareness by the farmers and community organizations. Hence, it is urgently needed to document, evaluate and harness the desired traits of these TRVs for ecological, economic, nutritional and health benefits. This study suggests taking greater cognizance of TRVs for their conservation, need-based crop improvement, and cultivation in the niche-areas owing to their importance in climate-resilient agriculture for overall sustainable rice farming in South Asia so as to achieve the UN’s Sustainable Development Goals.

scholarly journals An Overview of Rice QTLs Associated with Disease Resistance to Three Major Rice Diseases: Blast, Sheath Blight, and Bacterial Panicle Blight

Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 177 ◽  
Author(s):  
Seyedeh Soheila Zarbafi ◽  
Jong Hyun Ham
Keyword(s):  
Disease Resistance ◽  
Oryza Sativa L ◽  
Quantitative Resistance ◽  
Sheath Blight ◽  
Yield Potential ◽  
Burkholderia Glumae ◽  
Rice Varieties ◽  
Disease Resistant ◽  
Resistant Varieties ◽  
Panicle Blight

Rice (Oryza sativa L.) is one of the most important crops that are produced as human food, directly feeding people more than any other crop. Hence, it is important to increase the yield potential of rice through improving the disease resistance to prevailing rice diseases. Blast caused by the fungus Magnaporthe oryzae, sheath blight caused by the fungus Rhizoctonia solani Kühn, and bacterial panicle blight caused by the bacteria Burkholderia glumae and B. gladioli are serious rice diseases in many rice-producing regions. In spite of the chronic damages from these major diseases, the quantitative resistance to each of them is not known very well and any available disease-resistant varieties are rare or not stable. Although gene-for-gene resistance that is mediated by an R-Avr interaction has been intensively studied for blast, quantitative (or horizontal) resistance to a broad spectrum of races in M. oryzae is still poorly understood. Identification of the quantitative trait loci (QTLs) related to these diseases and using marker technology can facilitate marker-assisted selection to screen resistant traits in individual resources, which could ultimately lead to the development of novel disease-resistant rice varieties. This article is a summary of identified QTLs that are associated with rice diseases, including blast, sheath blight, and bacterial panicle blight that can be used in breeding programs.

scholarly journals Evaluating Sheath Blight Resistance in Rice Using Detached Tiller and Field Screening Method

2016 ◽  
Vol 1 ◽  
pp. 1-8 ◽  
Author(s):  
Bedanand Chaudhary
Keyword(s):  
Field Experiments ◽  
Agricultural Research ◽  
Disease Incidence ◽  
Block Design ◽  
Screening Method ◽  
Sheath Blight ◽  
Research Station ◽  
Rice Varieties ◽  
Progress Curve ◽  
Rice Genotypes

In present study physical resistance test on 12 rice varieties against sheath blight (ShB) caused by Rhizoctonia solani was examined. A detached tiller test was used to measure components of ShB physiological resistance at Regional Agricultural Research Station (RARS), Tarahara, Nepal. The varieties were evaluated in a randomized complete block design (RCBD) with 3 replications in year 2010-12. A sclerotium was inserted below the leaf collar of individual tillers maintained in tubes filled with water. Only the 56-day old susceptible plants were inoculated. After 7 days of inoculation, number of lesions, dead leaves, vertical sheath colonization and disease severity were measured. In 2011, field experiments were conducted with three replications to address morphological resistance in 28 rice genotypes. Disease incidence was recorded on 14, 21 and 28 days after inoculation. The number of dead leaves differed only numerically while disease variables significantly (P=0.004) varied among varieties. The other variables were highly correlated with each other. Cluster analysis of variables formed three varietal groups; Sabitri with lowest, and Jasmine-85 and Betichikon having highest values. Rice genotypes differed significantly (P=0.05) for disease incidence and area Under Disease Progress Curve (AUDPC). Tetep and IAC-165 had the lowest and highest terminal disease incidences and AUDPC, respectively. Sabitri, MTU-1010 and IR-26 recorded lower AUDPC values. Hence, Tetep and Sabitri could be used as donors in hybridization and their plant morphology could be considered as selection guide for improving ShB resistance in rice.Journal of Nepal Agricultural Research Council Vol.1 2015 pp.1-8

scholarly journals Quantification of the Components of Resistance to Rice Sheath Blight Using a Detached Tiller Test Under Controlled Conditions

Plant Disease ◽  
2011 ◽  
Vol 95 (12) ◽  
pp. 1507-1515 ◽  
Author(s):  
Laetitia Willocquet ◽  
Jagjeet S. Lore ◽  
S. Srinivasachary ◽  
Serge Savary
Keyword(s):  
Defense Mechanisms ◽  
Sheath Blight ◽  
Survival Duration ◽  
Lesion Length ◽  
Relative Role ◽  
Sources Of Resistance ◽  
Rice Varieties ◽  
Components Of Resistance ◽  
Controlled Conditions ◽  
Physiological Resistance

Resistance of rice (Oryza sativa) to sheath blight, caused by Rhizoctonia solani, is quantitative and involves two mechanisms: physiological resistance and disease escape. The epidemiological concept of components of resistance was applied using a detached tiller method under controlled conditions, to specifically address physiological resistance to sheath blight in rice. A sclerotium was inserted below the leaf collar of individual rice tillers maintained in tubes filled with water. Different variables were measured after incubation: number of lesions, lesion length, vertical sheath colonization, presence or absence of dark margin at the edge of lesions, and survival duration of the leaf blade. Several rice varieties reported to have different levels of susceptibility to sheath blight were assessed, together with varieties that are cultivated over large areas. Although numerical differences between rice varieties were observed for all disease variables, only the number of lesions significantly differed among varieties tested in this study. The varieties Pecos and IR64 had the consistently lowest and highest disease intensities, respectively. This methodology may allow the detection of sources of resistance that specifically involve defense mechanisms. When combined with field assessment, this methodology should also enable to quantitatively assess the relative role of both mechanisms of resistance to sheath blight.

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