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881.
882.
Romel Ahmed Mohammad Bela Uddin Mohammed Abu Sayed Arfin Khan Sharif Ahmed Mukul Mohammed Kamal Hossain 《林业研究》2007,18(4):301-304
An experiment was conducted to understand the growth inhibitory effects of aqueous extracts derived from Lantana camara L. (a globally recognized invasive alien weed) on six popular agricultural crops of Bangladesh. The test was conducted in sterilized petridishes with a photoperiod of 24 hours and an average temperature of 29℃. The effect of different concentrations ofL. camara leaf extracts were recorded and compared with control (i.e., distil water). Result showed different concentrations of aqueous leaf extracts caused significant inhibitory effect on germination, root and shoot elongation and development of lateral roots of receptor crops. Bioassays also indicated that the inhibitory effect was proportional to the concentrations of the extracts and higher concentration had the stronger inhibitory effect whereas the lower concentration showed stimulatory effect in some cases. The inhibitory effect was much pronounced in root and lateral root development rather than shoot and germination. 相似文献
883.
In the present study we describe a Nosema infection in a Phyllotreta nigripens population. The parasite was identified as Nosema phyllotretae. The spores are oval, 3.97±0.47 μm (2.85–4.75) in length and 2.19±0.36 μm (1.90–2.85) in width. The polar filament has commonly
14 coils. The spore wall is 138–200 nm thick and made up of a clear endospore (88–140 nm) and a uniform exospore (40–70 nm).
The polar filament measures 100–125 nm in diameter in the mature spirals. The polaroplast is thin lamellar. This study presents
P. nigripens as a new host for N. phyllotretae and a second infection locality in Turkey. 相似文献
884.
El Antri A Messouri I Bouktaib M El Alami R Bolte M El Bali B Lachkar M 《Fitoterapia》2004,75(7-8):774-778
A new isoquinoline-N-oxide alkaloid was extracted from the alkaloid fraction of a methanol extract of the seeds of Calycotome villosa subsp. intermedia. Its structure was established as 1-hydroxymethyl-6,7-dimethoxyisoquinoline-N-oxide (1) by spectroscopic techniques and X-ray diffraction analysis. 相似文献
885.
Md. Motiur Rahman Yasushi Furukawa Isao Kawata Mohammed Mahabubur Rahman Mahbubul Alam 《Small-Scale Forestry》2005,4(3):359-376
This study examines the species composition, diversity and economic importance of homestead forests in the household economy
of central Bangladesh. The study documents 57 homestead forest species and their main usage in 90 households across three
villages of Gazipur Sadar Upazila. Homestead forests in Bangladesh comprise a mixture of fruit, timber and bamboo species.
While superficially homestead forestry appears unimportant in rural livelihoods, in reality the contribution is huge, both
as a source of food security and for other necessary household materials. A clear understanding of the physical characteristics
and economic role of homestead forests in rural livelihoods is vital for ensuring sustainable resource management. Income
and production of homestead forestry on a per hectare basis are found to vary widely between landholding size classes. Significant
relationships are identified between forest performance (production and income) and species richness and education level.
Homestead forestry appears to be a potential subsistence income generating land-use practice in the study area. The economic
scope of homestead forestry can be further enhanced provided the appropriate species composition of the forest is achieved
and the education of forest owners is ensured through targeted management and policy interventions. 相似文献
886.
A study of lesion development in stems of Eucalyptus nitens following artificial inoculations with canker fungi was carried out on 16‐year‐old plantation trees. In a first trial cambium bark wounds on smooth‐ and rough‐barked trees were inoculated with the mycelium of nine species of canker fungi, including Endothia gyrosa. In a second trial spores or mycelium of E. gyrosa were applied directly onto undamaged or superficially wounded bark surfaces. Infection subsequent to artificial inoculation via wounding (whatever the wounding technique or type of inoculum) resulted in significantly larger external lesions (mean lesion area up to 35.6 cm2 20 months after inoculation) on smooth bark compared with those on rough bark (up to 19.0 cm2). Microscopic studies of infected rough and smooth bark suggest that, once smooth bark is compromised by wounding and artificial inoculation, the particular anatomical structure of smooth bark may offer less mechanical resistance to post‐penetration hyphal spread in comparison with rough bark. It is suggested that at a pre‐penetration stage under natural conditions spores of E. gyrosa more easily infect rough bark via cracks associated with this type of bark but not present in smooth bark. 相似文献
887.
Mohammed Abu Sayed Arfin Khan Fahmida Sultana Md. Habibur Rahman Bishwajit Roy Sawon Istiak Anik 《林业研究》2011,22(4):649-658
Species diversity and ethno-medicinal usage of 39 species of invasive plants were explored in and around two protected areas, Khadimnagar National Park (KNP) and Rema-Kalenga Wildlife Sanctu- ary (RKWS), of northeastern Bangladesh,. Status of invasive plants were investigated in 60 sample plots with 5 different habitat types, including forest, roadside, homestead, fallow land and others (ponds, canals, water logged areas, agricultural land, etc.). Data about the usage of invasive plants in traditional health care were collected through interviewing 110 households. Among the five habitat types, fallow land (28 species) pos- sessed the highest number of species, followed by roadside (25 species), forest (23 species), homestead (22 species) and others (13 species). Based on the survey, invasive plants of study areas were also categorized into five degrees of invasiveness e.g., naturalized, introduced, possibly invasive, moderately invasive and highly invasive. Additionally, there is the linear trend between degrees of invasiveness and use percentage of invasive plants. Total 39 species of invasive plants belonging to 29 fami- lies were recorded, which are generally used to treat 37 diseases, ranging from simple headache to highly complicated eye and heart diseases. The majority of the species used by the local inhabitants were herbs (16 spe- cies), followed by some shrubs (11 species), climbers (5 species), trees (5 species) and grasses (2 species). The use percentage of aboveground plant parts were higher (70.58%) than that of underground plant parts (16.18%). 相似文献
888.
Fien Degryse Rodrigo C. da Silva Roslyn Baird Ismail Cakmak Mustafa Atilla Yazici Mike J. McLaughlin 《植物养料与土壤学杂志》2020,183(2):248-259
Total Zn in fertilizer is a poor predictor of Zn availability in granular fertilizers. In this study, we compared different extraction methods using Zn fertilizers for which the agronomic effectiveness had previously been determined. Sixteen fertilizers were extracted by eight different procedures using five extractant solutions: water, 1 M ammonium acetate (pH 7.0), 74 mM EDTA (pH 7.0), 5 mM DTPA + 0.1 M MES (pH 6.2), and 0.12 M bis‐tris (pH 6). Modelling of Zn solubility and speciation was carried out with a chemical speciation program (Visual Minteq). The predicted solubilities were in good agreement with the observations, indicating chemical equilibrium. The three methods using pure water were highly correlated with each other and showed the strongest correlation with agronomic effectiveness (r = 0.81–0.90). The methods using extractants with strong pH buffering or high chelating capacity showed no or weak correlation with the agronomic effectiveness. Thus, water‐only based methods give the best indication of the availability of Zn in granular fertilizers, and are best suited for regulation or labeling of available Zn in fertilizer. 相似文献
889.
Anthony D. M. Glass Dev T. Brito Brent N. Kaiser Herbert J. Kronzucker Anshuman Kumar Mamaru Okamoto S. R. Rawat Mohammed Y. Siddiqi Salim M. Silim Joseph J. Vidmar Degen Zhuo 《植物养料与土壤学杂志》2001,164(2):199-207
Physiological methods, especially the use of isotopes of N, have allowed for the detailed characterizations of the several putative transport systems for nitrate and ammonium in roots of higher plants. In the last decade, the cloning of genes that appear to encode both high- and low-affinity transporters represent major advances, as well as substantiating the inferences based on earlier physiological methods. Nevertheless, the unexpected plethora of genes that have been identified now presents even greater challenges, to resolve their individual functions and to attempt to place these functions in a whole plant/environmental context. 相似文献
890.
Belalia R Grelier S Benaissa M Coma V 《Journal of agricultural and food chemistry》2008,56(5):1582-1588
Chitosan was chemically modified to produce quaternary ammonium salts in order to improve its antimicrobial activity and physicochemical properties. Quaternization of N-alkyl chitosan derivatives was carried out using alkyl iodide to elaborate water-soluble cationic polyelectrolytes ( N, N, N-trimethylchitosan, TMC). TMC was characterized by (1)H NMR spectroscopy; the quaternization degree was determined from (1)H NMR spectra and by titration of iodide ion. The antibacterial activity of hydroxypropylcellulose (HPC) films or coatings associated with chitosan or TMC as biocide was evaluated against the growth of Listeria monocytogenes and Salmonella typhimurium. The HPC-chitosan and HPC-TMC coatings exhibited a total inhibition on solid medium of both bacterial strains. Experiments conducted in liquid medium showed that the inhibitory activity against the growth of Listeria innocua was improved after chemical modification. Moreover, physicochemical properties of films were evaluated to determine their potential for food applications. The addition of the antibacterial agents showed a significant impact on the moisture barrier and mechanical properties of HPC films. 相似文献