27 research outputs found

    Effect of drought stress on growth, proline and antioxidant enzyme activities of upland rice

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    Responses of eight upland rice (Oryza sativa L.) varieties subjected to different drought levels were investigated in laboratory to evaluate eight local upland rice varieties against five drought levels (0, -2, -4, -6, and -8 bars) at germination and early seedling growth stage of plant development. Data were analyzed statistically for growth parameters; shoot length, root length, and dry matter yield, and biochemical parameters; proline and antioxidant enzymes activity (catalase, superoxide dismutase and peroxidase), were measured. Experiment units were arranged factorial completely randomized design with four replications. The drought-tolerant variety, Pulot Wangi tolerated PEG at the highest drought level (-8 bar) and showed no significantly difference relation to control. However, drought-sensitive variety, Kusam was markedly affected even at the lowest drought level used. Concomitantly, the activity of antioxidant enzymes catalase, peroxidase and superoxide dismutase in the drought-tolerant varieties increased markedly during drought stress, while decreased by drought stress in the drought sensitive variety. Consequently, this led to a marked difference in the accumulation of proline in the upland rice varieties. It may be concluded that the activities of antioxidant enzymes and proline accumulation were associated with the dry mass production and consequently with the drought tolerance of the upland rice varieties

    Integrated nutrient management in maize-legume-rice cropping pattern and its impact on soil fertility

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    Improved soil fertility is a precondition for increased crop production. Soil organic matter is a key factor in maintaining long-term soil fertility since it is the reservoir of metabolic energy, which drives soil biological processes involved in nutrient availability. Field experiments were conducted over three years during 2005 to 2007 at Bangladesh Agricultural University farm, Mymensingh, Bangladesh, using maize-legume-rice cropping pattern to see the effect of inorganic fertilizers along with organic manure and mungbean residue on soil properties and crop yields. For the first crop (maize), there were five treatments. After maize, seeds of mungbean and dhaincha (Sesbania) were sown as per treatments as legume crop. For rice (third crop), each of the treatments (T2 and T3 plots) were subdivided into six, so there were altogether 15 treatments. Integrated use of manure and inorganic fertilizers or Integrated Plant Nutrient System (IPNS) basis produced comparable seed yield of maize with the chemical fertilizers alone irrespective of moderate or high yield goal basis. The incorporation of Sesbania biomass and mungbean residue along with inorganic fertilizers for moderate yield goal produced identical grain yields of rice compared to fertilizers applied for high yield goal. After three years of cropping, the nutrient status of soils in control, fallow and mungbean residue removal plots showed a decreasing trend while incorporation of Sesbania biomass and mungbean residue had a positive effect on soil fertility. Therefore, addition of mungbean residues or Sesbania biomass to the fertilizer schedule ensures higher crop productivity and sustains soil fertility in maize-legume-rice cropping pattern

    Genetic Variation, Heritability, and Diversity Analysis of Upland Rice (Oryza sativa L.) Genotypes Based on Quantitative Traits

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    Upland rice is important for sustainable crop production to meet future food demands. The expansion in area of irrigated rice faces limitations due to water scarcity resulting from climate change. Therefore, this research aimed to identify potential genotypes and suitable traits of upland rice germplasm for breeding programmes. Forty-three genotypes were evaluated in a randomised complete block design with three replications. All genotypes exhibited a wide and significant variation for 22 traits. The highest phenotypic and genotypic coefficient of variation was recorded for the number of filled grains/panicle and yields/plant (g). The highest heritability was found for photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO 2 , and number of filled grains/panicle and yields/plant (g). Cluster analysis based on 22 traits grouped the 43 rice genotypes into five clusters. Cluster II was the largest and consisted of 20 genotypes mostly originating from the Philippines. The first four principle components of 22 traits accounted for about 72% of the total variation and indicated a wide variation among the genotypes. The selected best trait of the number of filled grains/panicle and yields/plant (g), which showed high heritability and high genetic advance, could be used as a selection criterion for hybridisation programmes in the future

    Leakage identification based on hydraulic transient analysis

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    Due to the ever-increasing degree of water loss, researchers and water utility corporations are becoming increasingly concerned about water leakage control. The purpose of this paper is to apply Empirical Mode Decomposition (EMD) and Synchrosqueezed Wavelet Transforms (SWT) as signal processing to locate leaks in pipelines. The objective of this study is related with to investigate leakage detection and signal processing methods, as well as to use them to detect and locate leaks. This paper explains how to run an experiment to visualize the most common types of leakage in a pipeline system. The experiment was set up that include a specific component of the piping system and leakage attached to it. This experimental test rig also attached with pressure sensor at the top of the solenoid valve. The piezoelectric pressure sensor is used in this experiment. The findings show that the method is superior to current signal processing methods for the conditions used. The recommendation is that research can be extended by running field test in order to observe the efficiency of the method used

    Application of Ikaz and direct quadrature for solving leakage in pipeline distribution by using transmission line modelling

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    A new transient-based advance towards single leak detection is proposed which requires a measurement station with an end at the pipe system. The method use the frequency response and gives adequate results using low frequency bandwidth. This research apply Empirical Mode Decomposition (EMD) as the method denoising the noisy pressure transient signal before the signal further analyze using instantaneous frequency analysis. Therefore EMD is the way to decompose into Intrinsic Mode Function (IMF) from the signal. However it is difficult to select suitable IMF. Thus the paper proposed the implementation of Integrated Kurtosis-based algorithm Z-filter technique for that allows automatic selection of relevant and appropriates IMF. This work demonstrated the synthetic pressure transient signal generates using transmission line modelling (TLM) in order to test the effectiveness of Ikaz as the autonomous selection of IMF. This paper implement the Direct Quadrature as the instantaneous frequency analysis. A straight fluid network was designed using TLM fixing with higher resistance at some point act as a leak and connecting to the pipe feature (junction, pipefitting or blockage). The analysis results using Ikaz revealed that the method can be utilized as an automatic selection of intrinsic mode function (IMF) although the noise level ratio of the signal is lower. Ikaz-kurtosis ratio is recommended and advised to be implemented as automatic selection of intrinsic mode function (IMF) through DQ analysis

    Implementation of I-kaz with Teager-Kaiser energy operator in solving leakage problem using synthetic signal

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    Transient event usually happen due to pressure surge inside water pipeline network by either opening or closing valve rapidly or water hammer phenomena. This paper focus on identification of leak signature using Empirical Mode Decomposition (EMD) with the implementation of Ikaz-kurtosis ratio while Teager Kaiser Energy Operator (TKEO) use as instantaneous frequency analysis (IFA). Two synthetic signal with different pipe characteristics was construct using transmission line modelling (TLM). It is show that Ikaz-kurtosis ratio give good result in selecting the intrinsic mode function (IMF) after EMD decomposed the signal into a series of IMFs. TKEO as post processing analysis extract all the information inside the signal that contaminated with noise. Its show that leakage position can be localize with maximum error less 7.3%. Meanwhile, Outlet position recorded 3.4% maximum. This conclude that this method apply for synthetic signal is acceptable for leakage detection

    Pipeline fault identification using synchrosqueezed wavelet transform based on pressure transient analysis

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    Brand modern technology of leak detection by using pressure transient analysis has been developed and interested to research due to its advantages such as low cost, simplicity and convenient to use. This technology uses the concept of signal reflections which identify pipeline features. The method used in this study was using a pressure transducer (piezoelectric pressure sensor) to obtain pressure transient respond generated by rapid opening and closing of solenoid valve. However, such reflections are very difficult to determine the pipe characteristic most probably because of excessive noise from other sources. Therefore, this paper proposed a method called Empirical Mode Decomposition (EMD) to decompose the reflection signal to its Intrinsic Mode Function (IMFs) and further analysis using continuous wavelet transform (CWT) to transform the signal into Time-Frequency domain and spectrum diagram. From the spectrum diagram, the characteristic of the pipe can be clearly display. From the finding results, it proves that this method not only useful for leak detection but also can determine the location of leak and its magnitude with error less than 10%

    Enhancing moringa nutritive value for impoverished populations and healthy wellbeing through proper nutrient enrichment

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    Taking into account the many cases of malnutrition related deaths in especially sub-Saharan Africa, the current research effort was conceived with the objective of appraising the nutritive potential of Moringa oleifera L. plant through the evaluation of proper agronomic practice that will enhance its nutritive potential. Measured quantity of dried roots, stem, and leaves portions of 5 months old Moringa oleifera L. seedlings, grown under various applied phosphorus (P) and potassium (K) rates were analysed for essential and non-essential amino acids content, total antioxidants, secondary metabolites (phenolics and flavonoids), and mineral nutrient elements. The high-performance liquid chromatography (HPLC) analysis revealed the presence of 9 essential and 7 non-essential amino acids, with a range of 4.24 to 10.04 gkg-1 recorded for leucine, threonine, histidine, glutamic acid, aspartic acid, and glycine. The 2,2ꞌ- diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) assay revealed strong antioxidants presence (up to 68% DPPH scavenging activity and a high level FRAP potential of 2500 mg ascorbic acid equivalent (AAE) / 100g dry weight (DW). Folin-Ciocalteu’s and aluminium chloride calorimetric assay revealed high levels of secondary metabolites (ranging from 1000 to 1350 mg gallic acid equivalent (GAE)/100g DW total phenolics and up to 2400 mg quercetin equivalent (QE)/1mg DW total flavonoids), and the nitric acid wet digestion procedure revealed a lot of mineral nutrient elements (with significant values of up to 19.13 g kg-1 maximum content acquired from calcium (Ca) and up to 9.90 g kg-1 recorded for iron (Fe). These nutritive components are noted to be highest in the leaves portion, followed by the roots, and then the stem parts. Based on its recognised rich base nutritive content, Moringa oleifera L. is a tree plant of nutraceuticals importance for impoverished communities

    Mapping of QTLs conferring resistance in rice to brown planthopper, Nilaparvata lugens

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    Brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacide), is a destructive insect pest of rice, Oryza sativa L. (Poaceae), in rice-producing areas worldwide. Host plant resistance is a major aspect of managing this pest. In this study, a mapping population consisting of 150 F3 lines, derived from a cross of MR276 and Rathu Heenati, was used to detect and analyse quantitative trait loci (QTLs) for the resistance to BPH. Composite Interval Mapping (CIM) was used for QTL detection. In total 10 QTLs controlling BPH resistance were mapped on chromosomes 1, 3, 6, 7, 9, 10, and 12. Four QTLs – qBph-1-1, qBph-3-1, qBph-6-1, and qBph-7-1 – were mapped on chromosomes 1, 3, 6, and 7 in the standard seedbox screening test, explaining 41% of the phenotypic variance. Two QTLs, qBph-6-1 and qBph-9-1, were detected on chromosomes 6 and 9 in the honeydew test, accounting for 32% of the total phenotypic variance. Moreover, four QTLs – qBph-3-1, qBph-6-1, qBph-10-1, and qBph-12-1 – were identified on chromosomes 3, 6, 10, and 12 expressing antixenosis to BPH and explaining 41% of the phenotypic variance. QTL qBph-3-1 was located in the chromosomal region between markers RM231 and RM3872 on chromosome 3, and QTL qBph-6-1 was located in the region between RM588 and RM204 on chromosome 6, indicating that these regions have a major effect in controlling the resistance to BPH in the population studied. The molecular markers linked to QTLs that are identified will be useful in the development of varieties resistant to BPH. Our study contributes to the development of genetic material for breeding programmes and marker-assisted selection (MAS) in rice to improve BPH resistance

    Molecular insights into the regulation of rice kernel elongation

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    A large number of rice agronomic traits are complex, multi factorial and polygenic. As the mechanisms and genes determining grain size and yield are largely unknown, the identification of regulatory genes related to grain development remains a preeminent approach in rice genetic studies and breeding programs. Genes regulating cell proliferation and expansion in spikelet hulls and participating in endosperm development are the main controllers of rice kernel elongation and grain size. We review here and discuss recent findings on genes controlling rice grain size and the mechanisms, epialleles, epigenomic variation, and assessment of controlling genes using genome-editing tools relating to kernel elongation
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