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31.
Md. Moshiur Rahman Ripon Biswas Litan Gazi Shaikh Tareq Arafat Md. Mostafizur Rahman Md. Asaduzzaman Sheikh Mustafizur Rahman Md. Nazmul Ahsan 《Aquaculture Research》2020,51(6):2275-2290
Multiple spawnings are special reproductive tactics that many fish evolved to obtain different types of direct and/or indirect spawning benefits. This has led to two pertinent questions: (a) what types of benefit does a commercially important fish provide during multiple induced spawnings annually? and (b) is there any trade‐off between traits during these spawnings? To address these questions, the present study was carried out with two separate experiments during two spawning events of an Indian major carp (Catla catla) to assess: (a) male's spawning performances and (b) female's spawning performances. The male's spawning data revealed that they produced significantly higher amount of milt and hatchlings during the first spawning, while they significantly reduced hatchling deformation rate, enhanced offspring survival rate and enlarged offspring body size during the second spawning. The female's spawning information unveiled no significant differences in total egg weight, hatching rate and hatchling deformation rate between the first and second spawning. However, females had significantly higher offspring survival rate during the first spawning and enhanced offspring body size during the second spawning. Interestingly, the analysis of trait associations revealed that males allocated energy with a trade‐off between milt weight and offspring survival rate, whereas females showed a trade‐off between hatching rate and offspring survival rate. Thus, the study provides some important information for carp breeders and associated stakeholders to know which spawning season is preferable for the higher production of eggs, milt and good quality larvae. 相似文献
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Md Nazrul Islam Khandkar-Siddikur Rahman Md Mezbaul Bahar Md Ahsan Habib Keisuke Ando Nobuaki Hattori 《Urban Forestry & Urban Greening》2012,11(4):460-464
Greenbelts are effective tools for mitigation of traffic induced air and noise pollution. In this study, the potential role of greenbelts along the roadside for the reduction of air pollution and noise levels has been assessed by using seasonally monitored data in a megacity of Bangladesh. Correlation analysis was performed between the vegetation status, measured by canopy density and shelterbelt porosity, and the total suspended particles (TSP) removal percentage. Further, the reduction of noise level was also analyzed. The results showed that the greenbelts greatly contributed to reduce TSP pollution and it was as much as 65%. Noise level reduction was also achieved up to 17 dB when compared to the open area. Moreover, TSP removal percentage was correlated to the crown density. Area having higher crown density demonstrated less air pollution and lower level of noise compared to the area having lower crown density. Greenbelt showed better performance in summer time than winter. 相似文献
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SUN Wei ZHANG Xue-fu Ahsan Morshed Gudrun Johannsen Johannes Keizer Yves Jaques Stefano Anibald LI Nan LIU Jia-yi 《中国农业科学(英文版)》2012,11(5):823-830
For the users' convenience of accessing the AGRIS resources quickly and using them fully,the paper decomposes the structure of AGRIS Search net,analyzes the users' requirement met for conducting a bili... 相似文献
34.
Akhtar M Hai A Awais MM Iqbal Z Muhammad F ul Haq A Anwar MI 《Veterinary parasitology》2012,186(3-4):170-177
This paper reports the immunostimulatory and protective effects of Aloe vera extracts (aqueous and ethanolic) against coccidiosis in industrial broiler chickens. The study was divided into two experiments. Experiment-I was conducted for the evaluation of immunostimulatory activity of A. vera and experiment-II demonstrated the protective efficacy of A. vera extracts against coccidiosis in chickens. Results of the experiment-I revealed significantly higher (p<0.05) lymphoproliferative responses in chickens administered with ethanolic extract of A. vera as compared to those administered with aqueous extract and control group. Microplate haemagglutination assay for humoral response on day 7th and 14th post primary and secondary injections of sheep red blood cells (SRBCs) revealed significantly higher (p<0.05) anti SRBC antibody (total Igs, IgG and IgM) titers in chickens of experimental groups as compared to the control group. None of the extracts, however, demonstrated significant effects on the development of lymphoid organs. Results of experiment-II revealed maximum protection (60%) in chickens administered with aqueous Aloe extract as compared to the ethanolic extract administered chickens (45%). Mean oocysts per gram of droppings in the control group was significantly higher (p<0.05) as compared to the chickens in both the experimental groups. Chickens administered with aqueous Aloe extract showed a minimal mean lesion score (2.3) followed by those administered with ethanolic Aloe extract (2.6) and control chickens (3.05) for caeca, and a similar pattern was observed for intestinal lesion scoring. Further, significantly higher weight gains and antibody titers (p<0.05) were observed in chickens administered with A. vera extracts as compared to those in the control group. It was concluded that A. vera may be a potential and valuable candidate to stimulate the immune responses and can be used successfully as an immunotherapeutic agent against coccidiosis in industrial broiler chickens. 相似文献
35.
Ali Ahsan Bajwa Aman Ullah Muhammad Farooq Bhagirath Singh Chauhan Steve Adkins 《Archives of Agronomy and Soil Science》2019,65(6):796-808
Parthenium weed (Parthenium hysterophorus L.) is an emerging weed species in direct-seeded aerobic systems of rice production. This two-year field study was conducted to evaluate the effect of five different densities (0, 5, 10, 15 and 20 plants m?2) of parthenium weed on rice yield and yield-related attributes. Parthenium weed produced ca. 38 to 178% higher biomass at its densities of 10 to 20 plants m?2 as compared to the lowest density of 5 plants m?2. The paddy yield and yield-related attributes were negatively affected with an increase in the parthenium weed density. In both years, the highest reductions in number of rice panicles (14 to 17%), panicle length (10 to 11%), number of grains per panicle (11 to 18%), 1000-grain weight (8 to 21%) and paddy yield (30 to 35%) were recorded at the highest parthenium weed density (20 plants m?2) tested. However, the lower densities of 5 to 15 parthenium weed plants m?2 also caused 11 to 24% and 12 to 26% losses in paddy yield during the years 2016 and 2017, respectively. Therefore, this weed species should be controlled below the density of 5 plants m?2 to avoid the substantial yield losses (over 15%) in direct-seeded rice. 相似文献
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37.
Arshad Naji Alhasnawi Che Radziah Che Mohd Zain Ahsan A. Kadhimi Anizan Isahakb Azhar Mohamad Mehdi Farshad Ashraf Wan Mohtar Wan Yusoff 《Journal of Crop Science and Biotechnology》2016,19(5):353-362
Salt stress is considered to be the most important abiotic stress and is the main problem in the interruption of the metabolic processes of plants, thereby limiting crop production. The present study was carried out to examine the effects of exogenously applied mushroom polysaccharides (β-glucan) on the growth of two rice varieties of Oryza sativa L. (MRQ74 and MR269) seedlings grown in vitro in 200 Mm sodium chloride (NaCl). Growth characteristics, including shoot and root height, and fresh and dry weight of salt-stressed rice seedlings were inhibited by sodium chloride treatment, the degree of which depends on the rice variety. The negative effects of salinity stress resulted in an imbalance of N, K+ Na+ and Na/K ratios and biochemical analysis activities a degradation of chlorophyll content in the plants. However, treatment with exogenously applied polysaccharides (β-glucan) ameliorated the stress generated by NaCl and improved the parameters mentioned above. The significance of the changes in growth and metabolism to salt stress tolerance in rice seedlings are discussed in the paper. 相似文献
38.
Increased calcium availability improves potato micropropagation and microtuberization 总被引：1，自引：0，他引：1
Summary Liquid scintillation counting (LSC) was used to screen six potato cultivars (Alpha, Bintje, Green Mountain, Kennebec, Russet
Burbank, and Shepody) and two wild species(S. microdontum andS. kurtzianum) for ability to take up the tracer45Ca2+ from treatment solutions containing high (15 mM) or low (5 mM) Ca2+ levels. In vitro potato micropropagation, microtuberization, and tissue calcium content, determined by flame atomic absorption
spectrophotometry (FAAS), were compared for the six cultivars when Murashige-Skoog basal medium Ca2+ level was increased from 3, to 5 or 15 mM. All aspects of growth were improved when medium Ca2+ level was 15 mM. Microtuber induction occurred earlier, leading to improved yield (19–31%), and microtuber tissue Ca2+ concentration was greater (38–226%). Cv. Bintje was the most efficient genotype at accumulating Ca2+ from treatment solutions or growth media containing high or low Ca2+ levels. It could be identified as a calcium-packer using either LSC or FAAS screening. 相似文献