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91.
Soil salinity and arbuscular mycorrhizal fungi (AMF) influence the soil hydrophobicity. An experiment was performed to determine the effects of soil salinity and AMF species on soil water repellency (SWR) under wheat (Triticum aestivum L.) crop. Six AMF treatments, including four exotic species (Rhizophagus irregularis, Funneliformis mosseae and Claroideoglomus claroideum, a mix of three species), one mix native AMF species treatment and an AMF-free soil in combination with four salinity levels (1, 5, 10, and 15 dS m?1) were used. The soil repellency index (RI) increased with salinity increment ranging from 2.4 to 10.5. The mix of three exotic and native AMF treatments enhanced the RI significantly compared to AMF-free soil in all salinity levels with one exception for native treatment at 1 dS m?1. Among individual AMF species, the C. claroideum treatment at 10 dS m?1 increased the RI by 67% compared to AMF-free soil. The native AMF treatment was more efficient in root colonization, glomalin production and SWR development at 10 and 15 dS m?1, compared to exotic species. In addition to the net positive effect of salinity on SWR, the AMF influences on the RI were greatly dependent on salinity levels.  相似文献   
92.
The aim of this 2-year field experiment was to investigate agronomic and economic efficiency of ground tire rubber and rubber ash as zinc (Zn) sources for wheat (Triticum aestivum L. cvs. Kavir and Back Cross) compared with a commercial zinc sulfate (ZnSO4). A similar rate of Zn was used by soil incorporation of 40 kg/ha ZnSO4, 200 kg/ha waste tire rubber ash, and 1000 kg/ha ground rubber. A no Zn added treatment was also considered as control. All Zn fertilizers significantly increased grain yield of wheat over the control, although effectiveness of rubber ash was greater than the other Zn sources. Wheat plants treated with rubber ash accumulated higher Zn in their grains compared with those treated with ground rubber and ZnSO4. Tire rubber ash had the highest agronomic and economic efficiency and contained low levels of cadmium (Cd) and lead (Pb). Therefore, it can be used as an economic substitution for commercial ZnSO4.  相似文献   
93.
Considering increasing rate of Iran population and consumption of wood panels, the authors investigated the per capita consumption of wood panels during the years from 1997 to 2007. The exponential smoothing method was used to obtain a per capita consumption pattern of wood panels in Iran for estimating demand of wood panels by the year of 2012. Results show that the consumption of particleboard, fiberboard, and medium density fiberboard in Iran will increase by 33%, 72% and 107 %, respectively, by the year of 2012; however, the consumption of plywood will increase only by 7% by 2012. The deficient amount of wood panels in Iran is estimated over 1400000 m3. The results of this study provide the technique reference for planners of wood panel industries in Iran in capital investment decisions.  相似文献   
94.
A model of supplying poplar wood for Iranian paper & wood factories   总被引:2,自引:2,他引:0  
Majid Azizi 《林业研究》2008,19(4):323-328
The objective of this research is to design a method for an appropriate alternative to supply poplar wood as raw material for wood and paper factories in Iran.Due to the destruction of the forests and lack of proper plantation,replacement of the forest wood by the fast growing wood is vital to satisfy all requirements of these factories.A hierarchy was used to prioritize benefits,opportunities,costs and risks (BOCR) using the Analytic Hierarchy Process (AHP) ratings approach.To evaluate the "control criteria" of the system,a control hierarchy was also created and prioritized by applying the Analytic Network Process (ANP).A total of four major control criteria in the system are prioritized where each one controls a network structure evaluated by using ANP.The final synthesis results of the system showed that internal poplar tree farming supplied by the forest product factories was the best choice among three potential alternatives (factory procurement,external procurement and mix procurement).  相似文献   
95.
Commercial areas containing Eucalyptus plantations have expanded in recent years due to increased demands for pulp, paper and bioenergy. One of the threats that can reduce Eucalyptus production is the eucalyptus rust disease caused by Austropuccinia psidii, a biotrophic fungus that affects a broad range of Myrtaceae. An accurate diagnosis tool for the early detection of rust disease could be useful in breeding programs for selection of resistant plants against rust, in phytosanitary purposes or in rust epidemics studies. The aim of the present work was to develop a SYBR Green-based quantitative real-time PCR (qPCR) assay for the early detection and quantification of A. psidii in Eucalyptus grandis leaves. Three sets of primers based on the A. psidii ribosomal DNA intergenic space region (IGS), beta-tubulin and elongation factor genes were designed and evaluated. The assays using the IGS primer set resulted in the highest detection efficiency, detecting a lower limit of 0.5 pg of A. psidii DNA. Under artificial inoculation in plants, A. psidii was detected immediately after pathogen inoculation until 240 h post-inoculation using qPCR. In field validation of the method, A. psidii was detected using qPCR in naturally infected leaves with or without rust symptoms. This easy and fast method can be used for an efficient detection of A. psidii in E. grandis leaves. The implications of this tool for rust studies are discussed below.  相似文献   
96.
Investigating population genetic structure and diversity, and resistance to pathogens in crop wild relatives are key steps to assess appropriate conservation and breeding programs. The Caucasian wild apple (Malus orientalis Uglitzk.) is an emblematic fruit tree of the Hyrcanian forest and is supposed to be a contributor to the cultivated apple genome (Malus domestica Borkh. Yet, no study has investigated its population structure, diversity and susceptibility to the two main pathogens of apples, the apple scab (Venturia inaqualis) and the powdery mildew (Podosphaera leucotricha). Here, we investigated population genetic structure and diversity of M. orientalis in the Hyrcanian forest as a mean to identifying future targeted populations for apple conservation and breeding programs. We genotyped using multilocus microsatellite 100 M. orientalis trees sampled in 14 sites. These trees were also screened for presence/absence of six (Rvi6, Vr, Rvi4, Rvi15, Rvi5 and Rvi11) and three (Pl-1, Pl-w, Pl-d) resistance genes to the apple scab and the powdery mildew respectively. Our results showed significant but weak between-site genetic differentiation and isolation by distance pattern suggesting substantial historical gene flow for M. orientalis in this area. We also detected a West-Eastern genetic structure across the Hyrcanian forest with five main populations showing admixture. We also showed a high diversity of resistance genes to apple scab across sites; in contrast, we only found one resistance gene to powdery mildew. These results are a first glimpse to settle wild apple conservation programs in Iran and pinpoint Iranian wild apple populations as an untapped source for apple breeding.  相似文献   
97.
98.
A field study was carried out from April 2014 to August 2014 for two consecutive planting cycles of Zea mays L. on Nyalau Series (Typic Tualemkuts) to determine the short-term effects of co-application of chemical fertilizers, rice straw compost, and clinoptilolite zeolite on (i) ammonium adsorption and desorption, (ii) nitrogen, phosphorus, and potassium uptake and use efficiency, and (iii) yield of Zea mays L. (cobs). Amending urea with rice straw compost and clinoptilolite zeolite improved nitrogen use efficiency because of temporary adsorption and desorption of ammonium on the exchange sites of compost and clinoptilolite zeolite. Combined use of chemical fertilizers, rice straw compost, and clinoptilolite zeolite enhanced uptake of nitrogen, phosphorus, potassium, calcium, and magnesium. Co-application of chemical fertilizers, rice straw compost, and clinoptilolite zeolite can improve the availability of soil nutrients. This approach can also improve nutrient use efficiency and yield of Zea mays L.  相似文献   
99.
Tropical acid soils are highly weathered as they exist under tropical environment with high rainfall and temperature throughout the year, which affects nitrogen availability. Soil organic nitrogen is important in estimating soil nitrogen availability. The combined use of urea and compost in this study was carried out to decrease sole dependence on urea, buffer soil acidification, and reduce nitrogen losses through leaching. Thus, soil buffering capacity, incubation, and organic nitrogen fractionation studies were conducted to determine soil buffering capacity, availability of total nitrogen, organic fractions nitrogen, and inorganic nitrogen in soil after 90 days of incubation following compost. Soil pH, buffering capacity, total nitrogen, organic nitrogen fractions, exchangeable ammonium, and available nitrate were higher in all treatments with compost and combined use of urea and compost. Total hydrolyzable nitrogen, ammonium-nitrogen, (ammonium + amino sugar)-nitrogen, amino sugar-nitrogen, and amino acid-nitrogen were higher in soils with urea and compost suggesting that decomposition of soil organic fractions nitrogen into inorganic nitrogen (ammonium and available nitrate was affected by the addition of urea and compost. Urea can be amended with compost to regulate availability nitrogen in soil for crop use.  相似文献   
100.
Untreated polyethylene terephthalate has limitation in some medical applications, such as wound dressing due to the hydrophobic property. Thereby, Tragacanth Gum (TG) as a natural polysaccharide utilized in polymer solution led to novel semi-bionanofibers of PET/TG blends (15:1, 15:2 and 15:3) through electrospinning method. Fourier transform infrared spectroscopy results confirmed the existence of hydrophilic groups of TG such as hydroxyl groups. Moreover, twice water uptake of PET/TG comparing with PET nanofibers indicated the hydrogel properties, also PET/TG nanofibers possessed high surface wettability through reduction of contact angle from 113 to 0°. Further, differential scanning calorimetry analysis indicated the alteration in the crystalline structure of PET/TG nanofibers that led to faster degradation in various pH values. The SEM images of PET/TG nanofibers displayed the greater average diameter with increasing TG content (283 nm) comparing with PET nanofibers (193 nm). Also introducing more TG in the nanofibers exhibited lower mechanical properties.  相似文献   
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