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51.
Effect of different seed treatments on dormancy breaking and germination in three species in arid and semi-arid lands 总被引：1，自引：0，他引：1
Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica (L.) Willd. ex Del., Prosopis juliflora (Sw.) DC. and Dodonaea viscosa (L.) Jacq. The following treatments were applied: T1, untreated seed (control); T2, sulphuric acid (97%) for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog (MS) medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds (80.8%-90.8%) and for scarified seeds of A. nilotica (50.2%) boiled in water. The germination indices, i.e., final germination percentage (FG), mean daily germination (MDG) and germination rate (GR), were significantly affected by treatments and species (p<0.01). 相似文献
52.
Kh. Salimi M.B. Hosseini R. Tavakkol-Afshari P.C. Struik 《The Journal of Horticultural Science and Biotechnology》2013,88(6):461-464
SummaryThe effects of a post-harvest application of gibberellic acid (GA3) at various concentrations (0, 10, 25, 50, or 100 mg l–1) and for different periods of incubation (1, 2, or 3 h) on the breaking of dormancy and on sprouting in potato (Solanum tuberosum L., cv. Marfona) minitubers of two ages (freshly-harvested or 1 week after harvest) were investigated. Compared with untreated, control minitubers, GA3-treated minitubers showed a significantly shorter period of dormancy (46 d), especially when the minitubers were treated at all concentrations immediately after harvest (41 d). GA3 treatment had a greater effect on dormancy in freshly-harvested minitubers than in 1 week-old minitubers, probably because of the reduced uptake of GA3 solution after skin-set. At lower concentrations of GA3, the period of dormancy tended to decrease the longer the minitubers were immersed in the GA3 solution. In contrast, at higher concentrations of GA3, the duration of immersion only had an effect up to 2 h and any longer immersion was ineffective. The average number of sprouts was not affected by GA3 concentration, or by the time of incubation, but was significantly higher for freshly-harvested minitubers (1.4) than for 1 week-old minitubers (1.2). The lengths of the sprouts increased with an increase in GA3 concentration, especially in freshly-harvested minitubers. Consequently, immersing freshly-harvested potato minitubers in a low concentration of GA3 (up to 25 mg l–1) for up to 3 h effectively shortened the period of dormancy and led to the formation of sprouts of optimum length. 相似文献
53.
This study investigates the occurrence and distribution pattern of infectious pancreatic necrosis virus (IPNV) within the pancreas, liver, kidney and spleen of naturally infected cultured rainbow trout, Oncorhynchus mykiss (Walbaum), using immunohistochemistry (IHC). A nested PCR was also employed to confirm the presence of the virus in the pooled tissues of the specimens. All the examined tissues except spleen were immunohistochemically positive for IPNV, but staining intensity and distribution pattern varied. The kidney tubules had the most intense and widespread staining by IHC, indicating a specific tissue tropism at least for this particular serotype. The nucleotide sequence had the greatest identity with the Sp serotype confirming the presence of the nucleic acid of IPNV in the pooled tissues. Based on the present findings, it could be concluded that the absence of lesions consistent with infectious pancreatic necrosis (IPN) disease in the H&E‐stained sections cannot rule out the presence of the IPNV, and the use of an alternative rapid confirmatory method such as IHC with formalin‐fixed, paraffin‐embedded tissue sections is helpful for the final diagnosis of IPN in rainbow trout. 相似文献
54.
Modeling of yarn and fiber properties has been a popular topic in the field of textile engineering in recent decades. The
common method for fitting models has been to use classical regression analysis, based on the assumptions of data crispness
and deterministic relations among variables. However, in modeling practical systems such as cotton spinning, the above assumptions
may not hold true. Prediction is influential and we should therefore attempt to analyze the behavior and structure of such
systems more realistically. In the present research, we investigate a procedure to provide a soft regression method for modeling
the relationships between fiber properties, roving properties, and yarn count as independent variables and yarn properties
as dependent (response) variable. We first selected the effective variables by multivariate test (mtest) and then considered
fuzzy least squares regression for evaluating relationship between cotton yarn properties such as tensile, hairiness, unevenness
and fiber properties that were measured by HVI system. We also used mean of capability index (MCI) to evaluate the goodness
of fit of the fuzzy regression models. The results showed that the equations were significant at very good MCI levels. 相似文献
55.
M. A. George S. V. Bhide R. J. Thengane G. H. Hosseini J. G. Manjaya 《Plant Breeding》2008,127(2):150-153
Lectin is one of the known antinutritional factors that deteriorate the soybean protein quality and development of cultivars with low lectin content will help to improve nutritional quality of soybean [Glycine max (L.) Merrill]. Therefore, attempts were made to induce mutations for low lectin content in the cultivar ‘MACS 450’. Soybean cultivar ‘MACS 450’ was subjected to combination treatments of γ‐rays and ethyl methane sulphonate (EMS) with an objective to induce variability for low lectin content. The treatments of different combinations of γ‐rays and EMS were 50 Gy + 0.2% EMS, 50 Gy + 0.4% EMS, 100 Gy + 0.2% EMS and 100 Gy + 0.4% EMS. Of the 3200 treated M1 seeds sown, 16 400 M2 plants were raised. In M2, 72 plants were identified for low lectin content [<40 × 105 haemagglutination unit (HAU)/mg] and were carried up to M5 generation. In M5 generation, lectin content in ‘MACS 450’ was 39.23 to 50.0 × 105 HAU/mg, and was compared with the nine true breeding lines identified having low lectin content, ranging from 2.3 × 105 to 27.46 × 105 HAU/mg. Three mutants were found to possess very low lectin content (ranging from 2.0 × 105 to 3.0 × 105 HAU/mg). Thus, the identified mutant lines with low lectin content will greatly improve soybean protein quality, thereby reducing financial burden on the soybean industry for processing soybean meal and also making it suitable for human consumption. All the mutants showed normal seed development, having soluble protein content similar or higher than that in the parent (32.0 mg/ml). This indicates that the change in lectin content does not have any negative impact on the plant growth and protein content. 相似文献
56.
Alleviation of Salinity Stress by Vermicompost Extract: A Comparative Study on Five Fennel Landraces
Abdollah Beykkhormizi Siavash Hosseini Sarghein Mohammad Reza Sarafraz Ardakani Seyed Mohammad Moshtaghioun Seyed Mousa Mousavi Kouhi 《Communications in Soil Science and Plant Analysis》2018,49(17):2123-2130
In the present study, interaction between salinity (0, 40, 80, 120 mM NaCl) and vermicompost extract (VCE) on five fennel landraces (Urmia, Mashhad, Shiraz, Boushehr, Isfahan) was investigated in a factorial experiment as completely randomized design to find the best salt-tolerant landrace and potential alleviating role of VCE. Results showed that Boushehr and Isfahan were the most tolerant and sensitive landrace to salinity, respectively. Application of VCE improved germination and growth of salt-treated fennels. The amylase activity of fennels was not affected by salinity and not improved by VCE. While sodium (Na+) content of root and shoot of all salt-treated fennels increased, their potassium (K) content decreased. Under salinity stress, root K content of VCE-amended landraces was more than that of not amended ones. VCE also caused an increase in calcium (Ca) content of root of salt-treated Shiraz and Urmia landraces. In conclusion, VCE can alleviate adverse effects of salinity stress on fennel. 相似文献
57.
Effect of dietary taurine and methionine supplementation on growth performance,body composition,taurine retention and lipid status of Persian sturgeon,Acipenser persicus (Borodin, 1897), fed with plant‐based diet 
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下载免费PDF全文 The aim of this study was to investigate the effects of dietary taurine and methionine on Persian sturgeon (Acipenser persicus) fed with plant‐based diets. To this purpose, sturgeons were fed with either of methionine + taurine‐supplemented (MT), without taurine supplementation (M) or without methionine supplementation (T) diets. Growth performance, body composition, tissue amino acids and serum glucose and lipids were studied at the end of the experiment. Results showed that the treatments T and MT had similar growth performance and feed efficiency, which were significantly higher than the treatment M. Dietary taurine and methionine significantly altered carcass and liver taurine and methionine contents. The highest serum glucose was observed in the treatment M and the lowest in treatment MT. Serum cholesterol and triglyceride levels in the treatments T and MT were similar and significantly higher than those of the treatment M. This study showed that Persian sturgeon needs taurine supplementation when fed with plant‐based diets, but the supplemented level seems to be lower than those of the other species. Taurine has hypoglycaemic and lipidogenesis effects on Persian sturgeon. However, further studies are required to illustrate taurine and methionine metabolism in Persian sturgeon. 相似文献
58.
Hossein Rangavar Abdulrasol Oromiehie Tahere Gholipour Arsalan Safarpour 《Wood material science & engineering》2017,12(4):211-219
Effects of nanoclay (NC) on physical and mechanical properties of wood-plastic composite (WPC) were studied here. Virgin, recycled, and mixed (50/50% of virgin/recycled) polyvinyl chloride (PVC) were used as the matrix in the WPC. Specimens with three NC contents of 1.5%, 3%, and 5% were manufactured; they were then compared with control specimens. Totally, 12 treatments were manufactured. The physical and mechanical properties were measured in accordance with the ASTM standards. The highest properties were found in specimens made from virgin PVC. Addition of recycled PVC resulted in significant decrease in all properties. NC improved all physical and mechanical properties studied in the present research project; the highest properties were observed in specimens with 5% of NC content. The improvement in properties was as a result of formation of bonds between the hydroxyl groups of NC with the wood flour components. It was concluded that NC would significantly improve the properties in all the three PVC types of virgin, recycled, and mixed. From an industrial point of view, it was concluded that mixing virgin and recycled PVC can be recommended not only to decrease production costs, but also to partially solve the problem of PVC residue which are not bio-degradable. 相似文献
59.
Mahbube Sadat Musavi Jad Seyed Abdolkarim Hosseini Ravandi Hossein Tavanai Razieh Hashemi Sanatgar 《Fibers and Polymers》2011,12(6):801-807
The aim of this paper is to investigate vertical wicking in polyacrylonitrile (PAN) electrospinning nanofiber yarn using image
analysis. Colored liquid rising phenomenon into the yarn and the distance of liquid rise were determined as a function of
time. The kinetics of capillary rise follows the Lucas-Washburn equation. The results show that capillary rise rate coefficient
is being reduced with increasing yarn twist, due to the reduction of continuity and size of capillaries. Increasing heat treatment
stretch from 0 % (draw ratio=1) to 50 % (draw ratio=1.5) increases the capillary rise rate coefficient, due to the more homogeneity
of capillary spaces in the yarn structure and increasing heat treatment stretch from 50 to 100 % (draw ratio=2) reduces capillary
rise rate coefficient, because of the low capillary length. The present study indicates that an appropriate choice in production
parameters of nanofiber yarn is all important in obtaining the desired properties of capillary rise. 相似文献
60.
Abbas Banj Shafiei Moslem Akbarinia Gholamali Jalali Mohsen Hosseini 《Forest Ecology and Management》2010
Most of world's forests of different climates have a history of fire, but with different severities. Fire regimes for broadleaf deciduous forests have return intervals that vary from many decades (or less) to centuries (or more). Iran has a total of 1.2 million ha of temperate forest in the north, where fires burn about 300–400 ha annually. This study focused on the impact of fire on forest structure, tree species quality, and regeneration composition (specially beech) in the Chelir forest of northern Iran. The results showed that forest fires changed the structure and had different effects on tree species composition between burned and control areas. Thin barked species such as oriental beech (Fagus orientalis Lipsky) and coliseum maple (Acer cappadocicum Gled.) have been affected more than those with thick bark, like hornbeam (Carpinus betulus L.) and chestnut-leaved oak (Quercus castaneifolia C.A. Mey). The density of oriental beech regeneration in the unburned area was greater than in the burned area, while the quantity of regeneration of hornbeam, coliseum maple and velvet maple (Acer velutinum Boiss) was higher in burned area. Forest fire had a greater effect on oriental beech quality, and changed regeneration composition in the burned area. Fire prevention activities should be considered as a silvicultural treatment for preserving these valuable forests. 相似文献