Preservation of Disease-free Shoot Tips of Potato Germplasm through in vitro System     

M K Biswas　M Hossain　R Islam 《中国马铃薯》2005,19(6):321-325

In vegetatively propagated crops,once system ati-cally infected w ith a viral disease,the pathogen canpassed from one generation to the next[1].Especially inpotato,contam ination by a pathogen can severely re-duce the total yield of the crop[2].Traditionally,potatovarieties have been and still m aintained in a fieldgene bank.M aintenance of potato germ plasm in thefield is a m ajor consum er of tim e,m anpower andspace aside from diseases and environm ental stresses.The m ajor disadvantage of …  相似文献   

Effect of acute haemorrhage on QRS amplitude of the lead II canine electrocardiogram     

PK DELLA TORRE  S. ZAKI  M. GOVENDIR  DB CHURCH  R. MALIK 《Australian veterinary journal》1999,77(5):298-300

OBJECTIVE: To examine the effect of acute haemorrhage on the QRS amplitude of the canine lead II surface electrocardiograph (ECG). DESIGN: Ten adult racing Greyhounds were tranquilised, anaesthetised, positioned in right lateral recumbency and connected to recording electrodes of an ECG unit. Baseline six-lead ECG traces were recorded, and further traces were obtained after one unit (460 mL) of blood, and then a second unit, were collected from the femoral artery. RESULTS: There was a consistent and progressive reduction in amplitude of the QRS complex in all leads during acute haemorrhage. QRS amplitude in lead II after removal of two units of blood averaged 74% of the baseline voltage, with individual values of 61 to 91% (P < 0.0001). There were even greater reductions in QRS amplitudes in lead aVL during haemorrhage. In three additional dogs, reductions in QRS voltages were shown to be accompanied by reductions in end-diastolic left ventricular internal dimensions measured echocardiographically. Furthermore, the effects of haemorrhage on the QRS amplitude and echocardiographic measurements were reversed when circulating blood volume was restored by re-infusion of blood removed previously. CONCLUSION: Acute haemorrhage corresponding to an approximately one-third reduction in blood volume caused a substantial reduction in QRS voltage of the surface ECG. It is postulated that this resulted from diminished ventricular distension as a consequence of reduced venous return. A similar mechanism may account for the small-amplitude ECG complexes associated with pericardial effusion, severe dehydration and hypovolaemia.  相似文献   

Development and evaluation of in vitro somaclonal variation in strawberry for improved horticultural traits     

M.K. Biswas  M. Dutt  U.K. Roy  R. Islam  M. Hossain   《Scientia Horticulturae》2009,122(3):409-416

Strawberry cultivation is not popular in Bangladesh due to the unpredictable climatic conditions and lack of proper cultivars. Using somaclonal variation, several new promising selections were generated and evaluated for their flowering and fruiting ability, adaptability and sustainability. To induce variation, plants were regenerated using various tissue culture techniques. Our results suggested that a high concentration of BAP in culture medium successfully resulted in the induction of somaclonal variation. Among the tissue culture techniques adopted in this study, meristem culture was most effective for induction of somaclonal variation. Twenty five putative somaclones with better horticultural features were subsequently selected and field evaluated for three clonal generations. Several of the selections reverted back to their original phenotype within 2–3 vegetative propagations. Three of the stable selections were distinct from each other in terms of fruit and other horticultural characters, and have potential for commercial cultivation in Bangladesh.  相似文献   

Different indices to characterize water use pattern of irrigated cauliflower (Brassica oleracea L. var. botrytis) in a hot sub-humid climate of India     

S. Sarkar  M.K. Nanda  M. Biswas  A. Mukherjee  M. Kundu 《Agricultural Water Management》2009,96(10):1475-1482

Frequency and depth of irrigation play crucial role in crop yield and use efficiency of water resource. To test this hypothesis a field study was carried out in November to January of 2001-2002 to 2003-2004 on a sandy loam (Aeric haplaquept) for quantifying the frequency and depth of irrigation on growth, curd yield (CY) and water use pattern of cauliflower (Brassica oleracea L. var. botrytis). Four irrigation frequencies depending on the attainment of cumulative pan evaporation (CPE) values of: 25 (CPE₂₅), 31(CPE₃₁), 38 (CPE₃₈) and 45 (CPE₄₅) mm were placed in main-plots, with three depth of irrigation (IW) of 35 (IW₃₅), 30 (IW₃₀) and 25 (IW₂₅) mm in sub-plots. Water use efficiency (WUE), net evapotranspiration efficiency (WUE_ET) and irrigation water use efficiency (WUE_I) were computed. Marginal water use efficiency (MWUE) and elasticity of water productivity (EWP) were calculated using the relationship between CY and seasonal actual evapotranspiration (SET). A continuous increasing trend in growth parameters, yield and WUE_I was recorded with the increase in SET from CPE₄₅-IW₂₅ to CPE₃₁-IW₃₀. However with further increase in SET the same decreased up to CPE₂₅-IW₃₅ regime. Highest WUE and WUE_ET obtained under CPE₃₈-IW₃₅ regime where SET value was 5% lower than the status of SET under CPE₃₁-IW₃₀. This study confirmed that critical levels of SET needed to obtain maximum curd yield or WUE, could be obtained more precisely from the knowledge of MWUE and EWP.  相似文献   

Impact of Long-Term Application of Organics,Biological, and Inorganic Fertilizers on Microbial Activities in Rice-Based Cropping System     

Nirmalendu Basak  Biswapati Mandal  Ashim Datta  Tarik Mitran  Sunanda Biswas  Debabrata Dhar 《Communications in Soil Science and Plant Analysis》2017,48(20):2390-2401

Organics, biological, and inorganic fertilizers play a crucial role for improving crop yield and soil properties. Accordingly, we assessed their impact on yield, microbial activities, and transformations of carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) in soils under a 12-year-old intensively cultivated rice (Oriza sativa L.), mustard (Brassica juncea L.), sesame (Sesamum indicum L.) system with sole inorganic (NPK); NPK + farmyard manure (NPKF); NPK + green manure (NPKG) (Sesbania sesban L.), and NPK + green manure + bio-fertilizer (NPKGB) (Azotobacter chroococcum+ pseudomonas putida) treatments in sub-tropical India. The system yield was much higher with NPKF (23%) and NPKGB (18%) than that with NPK. Organic supplementation had a favorable influence on soil microbial biomass C (C_mic), N (N_mic), and activities of extracellular enzymes. Results of principal component and multiple regression analyses showed significant influence of C_mic on system yield (R² = 91, p = 0.001) and S availability (R² = 62, p = 0.001). Similarly, mineralizable N and acid phosphatase could predict significantly soil available N (R² = 85, p = 0.001) and P (R² = 51; p = 0.001), respectively. Results thus indicated that integrated nutrient management (NPKF/G) improved system yield, nutrient accumulation, and microbial activities in soils.  相似文献   

Farmers’ perceptions and knowledge in using wastewater for irrigation at twelve peri-urban areas and two sugar mill areas in Bangladesh   总被引：1，自引：0，他引：1  

M.A. Mojid  S.K. Biswas 《Agricultural Water Management》2010,98(1):79-86

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Stimulation of growth performance without causing stress response in young red sea bream, Pagrus major (Temminck & Schlegel), by photoperiod manipulation     

Amal Kumar Biswas  Manabu Seoka  Kiyotaka Ueno  Kenji Takii  & Hidemi Kumai 《Aquaculture Research》2008,39(5):457-463

Three photoperiods (12L:12D, 16L:8D and 24L:0D) were used to investigate the growth performance and stress response in red sea bream, Pagrus major (body weight 200–400 g). Fish were fed a commercial diet to apparent satiation, two times a day for 8 weeks. Fish exposed to a 24L:0D photoperiod showed a significantly higher weight gain (%) than those exposed to other photoperiods (P<0.05). The best specific growth rate and feed conversion efficiency were achieved at 24L:0D and 16L:8D, without significant differences among them. Although fish exposed to 16L:8D showed a significantly higher plasma level of cortisol than those exposed to other photoperiods in the third week, there was no major variation in the cortisol level among the treatments either at the sixth week or at the end of this study. There were no significant differences either in the haematocrit level or the plasma levels of glucose, total cholesterol and total protein among the treatments during this study. The results revealed that the growth performance of red sea bream reared from 200 to 400 g can be stimulated significantly using a continuous (24L:0D) photoperiod without any measurable significant stress response in fish.  相似文献   

Fish meal replacement by soy protein from soymilk in the diets of red sea bream (Pagrus major)          下载免费PDF全文

A. Biswas  H. Araki  T. Sakata  T. Nakamori  K. Kato  K. Takii 《Aquaculture Nutrition》2017,23(6):1379-1389

Six isoenergetic diets were formulated as follows: fish meal (FM) 700 g kg^–1 (control, C), FM 300 g kg^–1 + soy protein concentrate 300 g kg^–1 (SPC), FM 300 g kg^–1 + enzyme‐treated SPC 300 g kg^–1 (ESC), FM 170 g kg^–1 + soy protein isolate 300 g kg^–1 (SPI), FM 160 g kg^–1 + enzyme‐treated SPI 300 g kg^–1 (ESI) and FM 150 g kg^–1 + conglycinin 300 g kg^–1(CG). Forty fish (3.9 g) were randomly distributed into each of eighteen 300‐L tanks, fed twice daily until satiation for 8 weeks. The final body weight, specific growth rate and condition factor did not show significant differences among the fish fed with diets C, SPC, ESC and ESI (p > .05). The survival was significantly lower in fish fed with diets SPI and CG. Feed efficiency was significantly higher in fish fed with diets SPC and C than in fish fed with other diets (p < .05). There were no significant differences in nutrients retention efficiencies in fish fed with diets C, SPC, ESC and ESI. A significantly higher phosphorus retention efficiency in fish fed with soymilk protein diets resulted in lower phosphorus discharge to the environment (p < .05). These results suggest that the soymilk proteins can comfortably replace 570–770 g FM kg^–1 diet of red sea bream juvenile, which will ensure significant ecological benefits through reducing phosphorus load to the environment.  相似文献   

Indicators of soil quality and crop productivity assessment at a long-term experiment site in the lower Indo-Gangetic plains     

Partha Sarathi Ghorai  Sunanda Biswas  Tapan Jyoti Purakayastha  Nayan Ahmed  Tapas Kumar Das  Radha Prasanna  Bharat Hanamant Gawade  Kallol Bhattacharyya  Kanchan Sinha  Priya Singh  Sujit Das 《Soil Use and Management》2023,39(1):503-520

Deterioration of soil quality under resource-intensive modern agriculture in the face of global climate change poses a huge risk to food security. Because of the complex nature, estimators of soil quality often rely upon a limited set of soil attributes, along with statistical data reduction techniques, for developing quality indices, whilst overlooking biological aspects and regional climatic variability. This study screened the most suitable soil quality indexing approaches for a rice-oilseed-based cropping system in the lower Indo-Gangetic plains (IGP). For this, surface soil samples (0–15 cm) were collected from an ongoing long-term fertilizer experiment with a rice-mustard-sesame cropping system in the IGP. The following treatments were assessed for their effect on soil quality: T₁-control, T₂-NPK (recommended NPK doses), T₃-NPKG (NPK + in situ green manuring), T₄-NPKGB (NPK + in situ green manuring + biofertilizer) and T₅-NPKF (NPK + farm yard manure FYM). We found that total organic carbon (TOC), β-glucosidase, CaCl₂ extractable S, alkaline KMnO₄ oxidizable N, activity of urease, amidase enzyme and mean weight diameter (MWD) were sensitive key indicators of soil quality. The NPKF treatment maintained the highest soil quality status (0.80–0.91), both under productivity and environmental protection goals, owing to the availability of decomposable carbon. Regression analysis showed a better agreement of equivalent rice yield with expert opinion (EO; R² = 0.89) than principal component analysis (PCA; R² = 0.76). Finally, we found that the expert opinion approach with the nonlinear scoring function was the best tool for soil quality assessment of the region.  相似文献