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Ecological fitness of brown planthopper, Nilaparvata lugens (stål), to rice nutrient management

Ecological Processes 2017年第1期6卷 149-158页

作者： Md.Mamunur Rashid Mahbuba Jahan khandakar s.islam Md.Abdul Latif Plant Physiology Division Bangladesh Rice Research Institute(BRRI)Gazipur 1701Bangladesh Department of Entomology Bangladesh Agricultural UniversityMymensingh 2202Bangladesh Plant Pathology Division Bangladesh Rice Research Institute(BRRI)Gazipur 1701Bangladesh

Introduction:The brown planthopper(BPH),Nilaparvata lugens(stål)(Hemiptera:Delphacidae),is a notorious insect pest of *** supplementation can alter plant biochemical compositions which may indirectly affect on ecological fitness parameters of its insect ***,few findings are available on nutrient-induced ecological fitness of BPH and relationship of BPH fitness parameters with its host rice plant biochemical ***:We studied the main and interaction effects of nitrogen(N),phosphorus(P),and potassium(K)inputs on BPH fitness,as measured by the following variables:nymph survival,nymphal duration,adult body weight,and its *** planthopper fitness parameters were regressed as function of rice plant(Oryza sativa)biochemical composition.A completely randomized design with four replications in a factorial scheme was used considering N,P,and K levels as ***:Nitrogen application to the host rice plants provided greater survival and enhanced body weight of *** nymphal duration was found to decrease with N subsidy that caused shorter generation time of *** compounds N and soluble protein(sP),total free sugar(TFs),and silicon(si)content in rice plant tissue correlated strongly with all fitness traits of ***,sP,and TFs associated positively with BPH survival and body weight,while negatively with nymphal *** contrast,si had negative correlation with BPH survival and body weight,but positive with nymphal *** supplementation to host plant contributed to increase BPH body *** of P with all parameters of BPH were weak except body weight which was highly significant and *** between N and P inputs demonstrated significant effect on BPH body *** of K had no significant effect on BPH survival and *** analysis did not detect significant relationship of BPH fitness parameters with plant tissue content of ***:The res

关键词： Nilaparvata lugens Nutrient management survival Nymphal duration Body weight

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Efficient ECG classification based on Chi-square distance for arrhythmia detection

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Journal of Electronic science and Technology 2024年第2期22卷 1-15页

作者： Dhiah Al-shammary Mustafa Noaman Kadhim Ahmed M.Mahdi Ayman Ibaida khandakar Ahmedb College of Computer science and Information Technology University of Al-QadisiyahAl Diwaniyah58001Iraq Intelligent Technology Innovation Lab Victoria UniversityMelbourne3011Australia

This study introduces a new classifier tailored to address the limitations inherent in conventional classifiers such as K-nearest neighbor(KNN),random forest(RF),decision tree(DT),and support vector machine(sVM)for arrhythmia *** proposed classifier leverages the Chi-square distance as a primary metric,providing a specialized and original approach for precise arrhythmia *** optimize feature selection and refine the classifier’s performance,particle swarm optimization(PsO)is integrated with the Chi-square distance as a fitness *** synergistic integration enhances the classifier’s capabilities,resulting in a substantial improvement in accuracy for arrhythmia *** results demonstrate the efficacy of the proposed method,achieving a noteworthy accuracy rate of 98% with PsO,higher than 89% achieved without any previous *** classifier outperforms machine learning(ML)and deep learning(DL)techniques,underscoring its reliability and superiority in the realm of arrhythmia *** promising results render it an effective method to support both academic and medical communities,offering an advanced and precise solution for arrhythmia detection in electrocardiogram(ECG)data.

关键词： Arrhythmia classification Chi-square distance Electrocardiogram(ECG)signal Particle swarm optimization(PsO)

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Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

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Rice science 2016年第3期23卷 119-131页

作者： Md Mamunur RAsHID Mahbuba JAHAN khandakar shariful islam Plant Physiology Division Bangladesh Rice Research Institute Department of Entomology Bangladesh Agricultural University

The brown planthopper(BPH),Nilaparvata lugens(st?l),appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients,nitrogen(N),phosphorus(P) and potassium(K),on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages,and changes in relative water content(RWC) of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants,and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants,which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N,K,si,free sugar and soluble protein contents,which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N,si,free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding,thereby contributed to higher tolerance of rice plants to brown planthopper.

关键词： Nilaparvata lugens relative water content host tolerance nitrogen phosphorus potassium rice nutrient subsidy

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Reduced tillage with residue retention improves soil labile carbon pools and carbon lability and management indices in a seven-year trial with wheat-mung bean-rice rotation

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Pedosphere 2022年第6期32卷 916-927页

作者： Rafeza BEGUM Mohammad M.R.JAHANGIR Mohammad JAHIRUDDIN Mohammad Rafiqul islam shaikh M.BOKHTIAR khandakar R.islam Department of soil science Bangladesh Agricultural UniversityMymensingh 2202(Bangladesh) soil Resource Development Institute Dhaka 1215(Bangladesh) south Asian Association for Regional Cooperation(sAARC)Agriculture Center Dhaka 1215(Bangladesh) The Ohio state University Columbus OH 43235(USA)

soil total organic carbon(TOC)is a composite indicator of soil quality with implications for crop production and the regulation of soil ecosystem *** reports on the dynamics of TOC as a consequence of soil management practices in subtropical climatic conditions,where microbial carbon(C)loss is high,are very *** objective of our study was to evaluate the impact of seven years of continuous tillage and residue management on soil TOC dynamics(quantitative and qualitative)with respect to lability and stratification under an annual wheat-mung bean-rice cropping *** soil samples were collected at 0-15 and 15-30 cm depths from a three-replicate split-plot experiment with tillage treatment as the main plots and crop residue levels as the *** tillage treatments included conventional tillage(CT)and strip tillage(sT).Residue levels were high residue level(HR),30%of the plant height,and low residue level(LR),15%.In addition to TOC,soil samples were analyzed for particulate organic C(POC),permanganate oxidizable C(POXC),basal respiration(BR),specific maintenance respiration rate(qCO_(2)),microbial biomass C(MBC),potentially mineralizable C(PMC),and TOC lability and management *** sT treatment significantly increased the TOC and labile C pools at both depths compared with the CT treatment,with the effect being more pronounced in the surface *** HR treatment increased TOC and labile C pools compared with the LR *** sT+HR treatment showed significant increases in MBC,metabolic quotient(qR),C pool index(CPI),C lability index(CL_(I)),and C management index(CMI),indicating improved and efficient soil biological activities in such systems compared with the CT ***,the stratification values,a measure of soil quality improvement,for POC and MBC were>2,indicating improved soil quality in the sT+HR treatment compared with the CT *** sT+HR treatment not only significantly increased the contents o

关键词： basal respiration carbon management index carbon stratification particulate organic carbon permanganate oxidizable carbon total organic carbon

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Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi(Ebenaceae)

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Asian Pacific Journal of Tropical Biomedicine 2016年第5期6卷 410-417页

作者： Muhammad Ali Khan Mahbubur Rahman Nazmul sardar saiful islam Arman Badrul islam Jahangir Alam khandakar Mamunur Rashid Golam sadik AHM Khurshid Alam Department of Pharmacy Bangabandhu Sheikh Mujibur Rahman Science and Technology University Department of Pharmacy University of Rajshahi Drugs and Toxins Research Division Bangladesh Council of Scientific and Industrial Research Product Development and Validation Department Square Pharmaceutical Limited Laboratory of Genetics Graduate School of BiostudiesKyoto University

Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBsB) on free radicals and ***: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, ***: Among the extracts, DBsB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBsB showed(95.760 ± 0.343)% and(67.460 ± 2.641)%scavenging with IC50of(3.10 ± 0.17) and(50.00 ± 3.11) mg/m L, respectively. The IC50 values of standard butylated hydroxytoluene and catechin(CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were(8.50 ± 0.25) and(75.00 ± 0.14) mg/m L,respectively suggesting that DBsB had a significant(P scavenging activity than standards. In lipid peroxidation inhibition assay, the inhibitory activity of the extracts and the standard was in the following order: DBsB > DBRB > CA > ***, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents[(412.00 ± 16.70) mg catechin equivalent/g)] of DBsB were higher than that of other extracts. In addition, the DBsB showed the moderate cytotoxic and anticancer ***: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer ***, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

关键词： Diospyros blancoi Free radicals Polyphenols Antioxidant Cytotoxicity Anticancer

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Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

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Journal of Forestry Research 2013年第4期24卷 791-795页

作者： khandakar showkat Osman M.Jashimuddin s.M.sirajul Haque sohag Miah Institute of Forestry and Environmental sciences University of Chittagong

This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of shifting cultivation no general trend was found for moisture content, maximum water holding capacity, field capacity, dry and moist bulk density, parti- cle density for some chemical properties between shifting cultivated land and forest having similar soil texture. Organic matter was significantly 0.05） lower in 1-year and 3-year shifting cultivated lands and higher in 2-year shifting cultivation than in adjacent natural forest. significant differences were also found for total N, exchangeable Ca, Mg and K and in CEC as well as for available P. slashed area showed higher soil pH. Deterioration in land quality starts from burning of slashing materials and continues through subsequent stages of shifting cultivation.

关键词： Chittagong Hill Tracts natural forest shifting cultivation soil properties

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Recognition of Bangla Handwritten Number Using Combination of PCA and FIs with the Aid of DWT

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Journal of Computer and Communications 2020年第9期8卷 109-125页

作者： samsunnahar khandakar Md. Imdadul islam Fahima Tabassum Risala T. Khan Department of Computer science & Engineering Jahangirnagar University Dhaka Bangladesh Institute of Information Technology Jahangirnagar University Dhaka Bangladesh

The structure of any Bangla numerical character is more complex compared to English numerical character. Two pairs of numerical character in Bangla resembles to be closed and they are: “one and nine” and “five and six”. We found that, handwritten Bangla numerical character cannot be recognized using single machine learning algorithm or discrete wavelet transform (DWT). Above phenomenon motivated us to use combination of DWT, Fuzzy Inference system (FIs) and Principal Component Analysis (PCA) to recognize numerical characters of Bangla in handwritten format. The four lowest spectral components of a preprocessed image are taken using DWT, which is considered as the feature vector to recognize the digits in first phase. The feature vector is then applied to FIs and PCA separately. The combined method provides recognition accuracy of 95.8% whereas application of individual method gives less rate of accuracy. Instead of storing the images itself in a folder, if we can store the feature vector of images achieved from DWT in tabular form. The records of table can be applied in FIs, PCA or other object detection algorithm. Although the technique used in the paper can detect objects with moderate rate of accuracy but can save huge storage against a benchmark database of images. If a tradeoff is made between storage requirements and accuracy of recognition, the model of the paper is preferable compared to other present state-of-art. Another finding of the paper is that, the spectral components of images acquired by DWT only matched with FIs and PCA for classification but do not match properly with unsupervised (K-mean clustering) and supervised (support vector machine) learning.

关键词： spectral Components Recognition Accuracy De-Noising Thinning scheme Principal Components

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Morphological and Genetical Variability among Rhizoctonia solani Isolates Causing sheath Blight Disease of Rice

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Rice science 2016年第1期23卷 42-50页

作者： Zakiah Rahman MONI Md Ansar ALI Md shahidul ALAM Md Asif RAHMAN Md Rejwan BHUIYAN Md salim MIAN khandakar Md IFTEKHARUDDAULA Md Abdul LATIF Mohammad Ashik Iqbal KHAN Plant Breeding Division Bangladesh Rice Research Institute Director Research Bangladesh Rice Research Institute Department of Botany Rajshahi University Department of Genetics and Plant Breeding Bangabandhu Sheikh Mujibur Rahman Agricultural University Plant Pathology Division Bangladesh Rice Research Institute

Eighteen isolates of Rhizoctonia solani collected from infected rice plants in four different locations of Bangladesh were studied by using morphological characters and molecular markers. Anastomosis study with a reference isolate confirmed that all the isolates belonged to R. solani. significant variation was observed in sclerotial size, shape and distribution. Un-weighted pair group method with arithmetic mean dendrogram constructed based on the Gower＇s general similarity coefficient showed that these isolates were grouped into four clusters at the 0.68 similarity coefficent according to morphological characters. Cluster I was a major cluster consisting of 13 isolates, while clusters Ⅱ to Ⅳ consisted of 1 or 2 isolates. Analyses by variable number of tandem repeat and amplified fragment length polymorphism markers showed that the isolates were grouped into five and three clusters at a similarity coefficient of 0.64 and 0.69, respectively. Although most of the variability was found between isolates from different regions as expected, significant variation was observed within the isolates collected from similar agro-ecological regions. Our results suggest the presence of different races of R. solani within the same local geographic regions.

关键词： rice Rhizoctonia solani fungal variability molecular marker morphological character

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Molecular characterization of sweet potato(Ipomoea batatas[L.]Lam)germplasms for desirable traits by using simple sequence repeats markers

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BIOCELL 2023年第1期47卷 227-237页

作者： khandakar ABUMDMOsTAFIZAR RAHMAN ABDUL sHUKOR JURAIMI MDREZWAN MOLLA MUHAMMAD AsYRAFMD HATTA ZULKEFLY BIN sULAIMAN sHAMIMA sULTANA AHMED GABER BENUKAR BIsWAs AKBAR HOssAIN Tuber Crop Research Centre Bangladesh Agricultural Research InstituteGazipur1701Bangladesh Department of Crop science Faculty of AgricultureUniversiti Putra MalaysiaUPMKuala Lumpur43400Malaysia Plant Genetic Resources Centre Bangladesh Agricultural Research InstituteGazipur1701Bangladesh Department of Agriculture Technology Faculty of AgricultureUniversiti Putra MalaysiaUPMKuala Lumpur43400Malaysia Regional Agricultural Research station Bangladesh Agricultural Research InstituteCumilla3500Bangladesh Department of Biology College of ScienceTaif UniversityTaif21944Saudi Arabia Department of Agronomy Bidhan Chandra Krishi ViswavidyalayaNadiaWB741252India Division of Agronomy Bangladesh Wheat and Maize Research InstituteDinajpur5200Bangladesh

Every breeding program that aims to create new and improved cultivars with desired traits mostly relies on information related to genetic ***,molecular characterization of germplasms is important to obtain target cultivars with desirable *** potato[Ipomoea batatas(L.)Lam]is widely considered the world’s most important crop,with great diversity in morphological and phenotypic *** genetic diversity of 20 sweet potato germplasms originating from Bangladesh,CIP,Philippines,Taiwan,and Malaysia were compared,which was accomplished by genetic diversity analysis by exploring 20 microsatellite DNA markers for germplasm characterization and *** information was effective in differentiating or clustering the sweet potato genotypes.A total of 64 alleles were generated using the 20 primers throughout the 20 germplasm samples,with locus IBs97 having the highest number of alleles(5),whereas locus IbU33 had the fewest alleles(2).The alleles varied in size from 105(IbU31)to 213 base pairs(IBs34).The Polymorphism Information Content(PIC)values for the loci IbL46 and IBs97 varied from 0.445 to ***97 has the highest number of effective alleles(3.704),compared to an average of *** average shannon’s diversity index(H)was 1.003,ranging from 0.673 in IbU3 to 1.432 in *** value of gene flow(Nm)varied between 0.000 and 0.005,with an average of 0.003,whereas genetic differentiation(FsT-values)ranged between 0.901 and *** sweet potato germplasm included in this study had a broad genetic ***1 ***9 and sP12 ***18 germplasm pairings had the greatest genetic distance(GD=0.965),while sP1 ***2 germplasm couples had the least genetic diversity(GD=0.093).Twenty genotypes were classified into two groups in the UPGMA dendrogram,with 16 genotypes classified as group“A”and the remaining four genotypes,sP10,sP18,sP19,and sP20,classified as group“B.”According to cluster analysis,the anticipated heterozygosity(gene diversity)of Nei

关键词： sweet potato simple sequence repeats(ssRs) Genetic diversity Dendrogram

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黄麻早花

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中国麻作 1987年第4期9卷 43-43页

作者： A. L. khandakar 陈洪福

黄麻开花是限制黄麻纤维产量的一个因子．黄麻一开花。就导致茎杆分叉，麻茎停止伸长，表明黄麻开花期在黄麻栽培中十分重要。我们在本文将对黄麻早花的一些重要原因进行讨论。

关键词：早花黄麻纤维茎杆开花期栽培产量伸长

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