排序方式： 共有14条查询结果，搜索用时 15 毫秒
1.
ABSTRACT In western North America, Douglas-fir (Pseudotsuga menziesii) is the most economically important conifer species susceptible to laminated root rot caused by Phellinus weirii. While attempting to internally sequence an endochitinase found to be up-regulated in P. weirii-infected Douglas-fir roots, we obtained overlapping peptide fragments showing 28% similarity with a PR-5 thaumatin-like protein (TLP) designated PmTLP (Pm for Pseudotsuga menziesi). A rabbit polyclonal antibody was reared against a synthetic peptide composed of a 29-amino-acid-long, conserved, internal sequence of PmTLP and purified by immunoaffinity. Western immunoblot analysis of infected roots of 24-year-old coastalfir showed significantly higher amounts of PmTLP (P < 0.01) closest to the point of P. weirii inoculation and infection than in uninfected regions of the same root. The antibody was also used to screen for PmTLP in roots of 25-year-old interior Douglas-firs naturally infected with a related pathogen, Armillaria ostoyae, and results showed significantly higher levels of PmTLP in bark tissues adjacent to infection (P < 0.05) than in uninfected tissue. Using polymerase chain reaction (PCR)-based cloning, the cDNA of PmTLP was shown to have a 702-bp open reading frame with a signal peptide cleavage site at 155 bp corresponding to a 29-amino-acid-long residue prior to the start of the N-terminal. Based on the deduced amino acid sequence, the molecular mass of the putative PmTLP was calculated to be 21.0 kDa with an isoelectric point of 3.71. Alignment analysis of PmTLP cDNA with a representative genomic DNA PCR sequence showed presence of one intron of variable size, within the coding region. The induction of PmTLP at the site of root infection and its presence in needle tissue suggests a general role for this protein in adaptation to stress and may be part of an integrated defense response initiated by the host to impede further pathogen spread. 相似文献
2.
Arezoo Soltani Prem L. Sankhayan Ole Hofstad Farshid Eshraghi Abbas Arabmazar 《Small-Scale Forestry》2017,16(3):347-365
Construction of new roads in rural areas is closely linked to market accessibility and economic growth. It also leads to exploitation of natural resources that may accelerate deforestation. These conflicting effects of an improved road network on rural development and depletion of forest resources present a serious challenge to policy makers interested in sustainable development. This paper investigates the effects of road networks on biological and socio-economic behaviour. The analysis was conducted by using a non-linear bio-economic model for a community in southern Zagros, Iran where they manage the adjoining forest according to traditional rules. Data for the model were obtained through village surveys and published resources. The model followed a holistic approach by incorporating a number of livelihood activities, such as, crop cultivation, goat husbandry, charcoal production and hiring out of community labour, along with several logical resource constraints. It was run over a period of 45 years. The results showed that new roads can either fuel forest degradation or contribute to forest protection depending on the choice of policy options. The study concludes that construction of new roads should be accompanied by policies aimed at higher state controls over newly accessible forest areas through regulatory measures, creation of new non-farm employment opportunities and strengthening of traditional institutions through providing extension services for local communities and facilitating NGO involvement so as to minimize the adverse effects on forest resources. 相似文献
3.
Sharifi Arezoo Gorji Manuchehr Asadi Hossein Pourbabaee Ahmad Ali 《Paddy and Water Environment》2014,12(1):139-145
Paddy and Water Environment - The aim of this study was to evaluate the impacts of land leveling on some of soil properties. Land leveling as an effective strategy for paddy land management is one... 相似文献
4.
Kiarash Roohani Sheau Wei Tan Swee Keong Yeap Aini Ideris Mohd Hair Bejo Abdul Rahman Omar 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(4):447-457
A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site 112RRRKGF117 and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens. 相似文献
5.
N. A. Khosh Kholgh Sima S. Tale Ahmad R. A. Alitabar Arezoo Mottaghi Mohammad Pessarakli 《Journal of plant nutrition》2013,36(9):1411-1428
Salinity is one of the most important agricultural problems in Iran. The effect of different levels of salinity and phosphorus on shoot length, root and shoot fresh and dry weight, nutrient elements (sodium (Na+), potassium (K+), phosphorus (P) and chloride (Cl?), proline and soluble sugar contents of barley were investigated. Two cultivars of barley, Hordeum murinum (wild resistant germplasm) and Hordeum vulgar, variety Afzal were treated in vegetative stage under hydroponics condition in a factorial arrangement based on completely randomized block (CRB) design with four levels of salinity [0, 100, 200 and 300 mM sodium chloride (NaCl)] and three levels of phosphorus (15, 30 and 55 μm L?1) with three replications. By increasing salinity, all the measured parameters, except sodium (Na+) content were reduced. Furthermore, with increased in phosphorus levels from 15 to 55 μm, Na+ content of the plant shoots decreased, but length, fresh and dry weights of roots and shoots and K+, P, Cl?, proline, and soluble sugars content of the shoots increased. The results indicated that accumulation of mineral ions for osmotic adjustment and restriction of Na+ accumulation in shoots were involved in phosphorus enhancement of the salt tolerance of barley. Thus, it seems that in saline soils, where there is no possibility for soil leaching and amending, application of phosphorus fertilizers can lead to a satisfactory growth and production in barely yield. 相似文献
6.
Babak Motesharezadeh Keyvan Valizadeh-Rad Arezoo Dadrasnia Hormoz Amir-Mokri 《Journal of plant nutrition》2017,40(4):532-542
The use of chemical fertilizers in four countries (Iran, Malaysia, Australia and US) was compared over a period of 30 years. Results showed that the use of nitrogen as a nutrient in Australia, Iran and Malaysia had a wide change due to the population growth and the need to provide food for the community. By growing the trend of urbanization, the ratio of population parameters of arable land has been reached from 3 ha/person in 1980 to less than 2 ha/person in 2010. Finally, the ratio between the main nutrient elements in Iran, Malaysia, the US and Australia was 100-70-0.2, 100-80-145, 100-43-51 and 100-329-100 in 2010, respectively. Regardless of the specific reasons and differences in sources of soil, crop and climate in these countries, the ratio in US is much closer to the balance of plant and stabilizes the long optimum ratio during the period. 相似文献
7.
Polymer matrix composites (PMCs) owing to their outstanding properties such as high strength, low weight, high thermal stability and chemical resistance are broadly utilized in various industries. In the present work, the influence of silanized CaCO3 (S-CaCO3) with 3-aminopropyltrimethoxysilane (3-APTMS) coupling agent at different values (0, 1, 3 and 5 wt.% with respect to the matrix) on the mechanical behavior of basalt fibers (BF)/epoxy composites was examined. BF-reinforced composites were fabricated via hand lay-up technique. Experimental results from three-point bending and tensile tests showed that with the dispersion of 3 wt.% S-CaCO3, flexural strength, flexural modulus, tensile strength and tensile modulus enhanced by 28 %, 35 %, 20 % and 30 %, respectively. Microscopic examinations revealed that the development of the mechanical properties of fibrous composites with the incorporation of modified CaCO3 was related to enhancement in the load transfer between the nanocomposite matrix and BF as well as enhanced mechanical properties of the matrix part. 相似文献
8.
Arezoo Meshkat Roohani Abdolmohammad Abedian Kenari Maryam Fallahi Kapoorchali Mohammad Sayad Borani Sayed Jalil Zoriezahra Amir Hossein Smiley Mohammad Esmaeili Artur Nishioka Rombenso 《Aquaculture Nutrition》2019,25(3):633-645
Spirulina has been highlighted as a valuable complementary ingredient in aquafeeds due to its high protein and vitamin content, in addition to other nutritional benefits. To evaluate the effect of dietary spirulina inclusion in fish meal sparing (FMS) on juvenile Caspian brown trout as a slow‐growth fish, a complete randomized experimental design was developed with five treatments: 0% (control), 2% FMS (13.2 g/kg spirulina in diet), 4% FMS (26.4 g/kg spirulina in diet), 6% FMS (39.6 g/kg spirulina in diet) and 8% FMS (52.8 g/kg spirulina in diet). Six hundred juveniles (11.0 ± 1.0 g) were assigned to 15 experimental tanks. Although this fish is sensitive to diet composition, fish fed the 6% FMS and 8% FMS diets had a significantly higher weight gain rate (239.51% and 231.27%) and specific growth rate (1.74% bw per day and 1.71% bw per day) compared with those fed the control diet. Furthermore, 6% FMS and 8% FMS treatments had statistically higher protein efficiency (0.76 and 0.78), lipid efficiency (1.89 and 1.94) and statistically lower feed conversion ratio (2.47 and 2.41) compared with other treatments, respectively (p < 0.05). In terms of whole‐body composition, the higher amount of protein and lower content of lipid were observed in fish fed the 8% FMS diets as compared to control. Although no significant differences in ash and moisture content were observed, the highest protein deposition (157.3 g/kg) and the lowest lipid content (77 g/kg) in whole body were reported in fish fed 8% FMS diet. Based on the fillet fatty acid outcome, fish fed the 8% FMS diet had significantly higher saturated fatty acids (SFAs), C20:3n‐6, C18:3n‐3, polyunsaturated fatty acids (PUFAs) and total n‐3 fatty acids as compared to those fed the control diet (p < 0.05). Accordingly, increasing dietary spirulina content significantly enhanced the amount of these fatty acids in fish fillet. As regards of whole‐body amino acid profile, arginine and lysine in fish fed 6% FMS and 8% FMS diets were higher and lower than in those fed the control diet, respectively (p < 0.05). Fillet and skin colour parameters, such as luminosity, redness and yellowness, significantly increased with spirulina supplementation with the 8% FMS treatment displaying higher values than the control. In summary, according to our results, 8% FMS (52.8 g/kg spirulina in diet) treatment improved juvenile Caspian brown trout growth, carcass composition and pigmentation. 相似文献
9.
A deterministic dynamic bio-economic model was used to analyse different management options for goats and charcoal production in a forest in Zagros, Iran. The study sought optimal management options from a local community point of view considering net present value (NPV) of income from sale of goats and charcoal under different restrictions on forest harvest imposed by the state. The model was run under six model scenarios: (1) business as usual (BAU), (2) no state intervention, (3) no forest harvesting, (4) strict quota, (5) medium quota and (6) loose quota on charcoal production. The scenarios' results were compared based on four numeric criteria (NPV of income from goats and charcoal, development of standing volume and tree size diversity in forest, interaction between goat population and oak forests) and one subjective criterion (state budget for managing forest). The results indicated that two main challenges exist in forest management in Zagros; (1) to determine the balance between local communities' welfare and biological stability of the forest and (2) to choose between a cheap management regime prohibiting wood harvest but implicitly accepting some illegal charcoal production and a more expensive, but legal, harvest regulation through charcoal production quota. We conclude that the BAU scenario, where forest harvesting was prohibited de jure, but some illegal charcoal production was still undertaken, was the only viable management, which also is practically acceptable by both state and local communities. 相似文献
10.
ABSTRACT In the present study, in a candidate gene approach, a class IV chitinase gene (PmCh4A) of pathogenesis-related family three was cloned and characterized in western white pine (Pinus monticola). PmCh4A chitinase expression in the different organs of healthy seedlings was below levels detectable by western immunoblot analysis using an antibody raised against PmCh4A protein. However, a 27-kDa isozyme of PmCh4A accu mulated in both susceptible and slow-canker-growth (SCG) resistant seedlings after infection by Cronartium ribicola. As with fungal infection, the application of a signal chemical (methyl jasmonate) and a protein phosphatase 1 and 2A inhibitor (okadaic acid) increased the PmCh4A protein accumulation. Furthermore, another 26-kDa isozyme was expressed specifically in SCG resistant seedlings, providing a potential tool for marker-assisted selection in forest breeding. Wounding treatment also induced expression of the protein. These data suggest that the class IV chitinase PmCh4A is involved in the defense response of western white pine to infection and abiotic stresses. 相似文献