72 research outputs found
Seed germination and seedling establishment of some wild almond species
Wild almond species are important genetic resources for resistance to unsuitable condition, especially drought stress. They have been used traditionally as rootstocks in some areas of Iran. So far, 21 wild almond species and 7 inter species hybrids have been identified in Iran. To study seed germination and seedling establishment of some of these species, three separate experiments were designed. In the first experiment, the application of gibberellic acid (GA3) (0, 250, 500 and 750 ppm) for 24 h was studied on germination characteristics of four wild almond accessions after stratification at 5 ± 0.5°C in Perlite media. Germination percentage, index vigor and root initiation factors were different in almond accessions, but were not affected by hormonal treatments. In the second experiment, seeds of another six wild almond accessions were stratified to compare their germination ability. Germination percentage, index vigor and root initiation were different among accessions significantly. In the last experiment, the establishment and vigor of 14 accessions from eight almond species have been evaluated in plastic bags in outdoor conditions. Two ecotypes of Prunus spp. had the highest stem diameter and length at all growing stages.Keywords: Amygdalus, germination percentage, index vigor, root initiation, stem length, stem diameter
Effects of Hydrogen Peroxide on Decreasing Microbial Contaminations in Raisins of Bavanat Region
Introduction
 Raisins are dried grapes and are prepared from some varieties of grapes (Vitis vinifera) in different ways, such as exposing grapes to direct sunlight and mechanical methods. There is a possibility of contamination of various types of raisins with different microorganisms during the stages of harvesting and drying grapes, transportation and marketing of raisins, especially when they are presented in open boxes. The traditional process of preparing and packing raisins in Bovanat region (the main raisin production area of Fars province) makes this product prone to microbial contamination dangerous for human health. The history of consumption of raisin is very old. The Bible provides the first written mention of raisin around 1000 B.C., drying is one of the oldest methods of food preservations; the main purpose of this experiment is reducing the moisture content to level which allows safe storage without spoilage. It has been reported that the use of hydrogen peroxide (H2O2) treatments reduces the microbial contamination loads in dried raisins. Moreover, washing with hydrogen peroxide solution can markedly reduce the loads of human pathogens including Escherichia coli. Primitive methods of making and packaging of raisins in Bavanat region contribute to make them vulnerable to microbial contamination and may be harmful for health. This research was conducted in order to determine the initial microbial contamination on the surface of three types of raisins prepared from the Keshmeshi grape cultivar and using hydrogen peroxide to reduce these microbial contaminations.
Materials and Methods
The use of hydrogen peroxide as a potential antimicrobial treatment was investigated for three types of raisins in Bovanat region. For this purpose, three samples of raisins (Sun-dried, Shade-dried and Sultana raisins) have investigated. Raisins samples randomly were purchased from a local retailer in Shiraz (Iran). For this experiment, raisin samples with uniform size were selected and damaged or diseased berries were discarded. Two concentrations of hydrogen peroxide applied to microbial disinfection were 0% and 0.9%. The raisins that were prepared underwent a treatment process where they were dipped for 5 minutes in solutions containing either 0% or 0.9% hydrogen peroxide. Afterward, the raisins were washed with distilled water for 1 minute to remove any residue. A control group was also included, consisting of raisin samples treated with water (0% hydrogen peroxide). For each sample, measurements were taken for microbial count, population of yeasts and other molds, Aspergillus, Coliform bacteria, and Escherichia coli. The experiment was designed as a factorial (2x3) based on a completely randomized block design with 3 replications. The data were analyzed using SPSS 22.0, and mean data were compared using Duncan's multiple range tests at a 1% probability level.
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Results and Discussion
 The results showed that there was a significant difference (Pâ€1%) between hydrogen peroxide concentration treatments regarding to microbial contamination. There was also a significant difference (Pâ€1%) between the raisin samples in terms of microbial contamination. The results also revealed the presence of high amount of microbial infection on surface of all raisin samples. The microbial contamination load of Sultana raisins was higher than other raisins. The results also indicate that Escherichia coli was not detected in both sun-dried and shade-dried samples, but it was observed in Sultana raisins. Surface disinfection of Sultana raisin samples with 9% of hydrogen peroxide removed Escherichia coli infection. Hydrogen peroxide was effective in reducing the microbial contamination of all three raisin samples. It seems hydrogen peroxide to be more effective in reducing microbial contamination in sun-dried and shade-dried samples. Sultana raisin had highest contamination of mold and yeast while sun-dried and shade-dried raisins were lowest. The effect of hydrogen peroxide on reducing mold and yeast contamination was not the same in all raisin samples, so that the highest effect on reducing mold and yeast contamination was found in sun-dried and shade-dried raisins. The least effect on this contamination was observed in sultana raisins. Aspergillus was not detected in sun-dried and shade-dried samples but it was observed in sultana raisins. Hydrogen peroxide was not effective against Aspergillus. The microbial contamination of all raisin samples which affected by 0.9% hydrogen peroxide was decreased significantly (Pâ€1%). Effect of hydrogen peroxide at 0.9% on removing of microbial infection in sun-dried and shade- dried raisins was similar and it was more than Sultana raisins.
Conclusion
All three raisin samples were infected with Coliform bacteria, mold and yeast. In the case of Escherichia coli infection, it was detected only in sultana samples. Hydrogen peroxide was effective in reducing the microbial infection of all raisin samples. It was more effective in reducing the total number of microbes in sun-dried and shade-dried raisins. Hydrogen peroxide with a concentration of 0.9% is effective for eliminating the microbial infection of raisins, and the use of hydrogen peroxide with a concentration of 0.9% can be used to disinfect raisins
Modeling leaf production and senescence in chickpea
Quantitative information regarding leaf area development in chickpea (Cicer arietinum L.) is scarce. Data from
four field experiments with a range of treatments including genotype, sowing date and plant density across 4
location-season combinations were analyzed to quantify main effects of temperature, photoperiod and plant
population density on plant leaf area in chickpea. All experiments were conducted under well-watered
conditions. Maximum rate of main stem node development was 0.72 nodes d-1. Cardinal temperatures for node
appearance were found as 6.0, 22.2 and 31.0 oC for base, optimum and ceiling temperatures, respectively. Plant
density had no effect on cardinal temperatures for leaf appearance and phyllochron. Leaf senescence on the main
stem started when the main stem had about 12 nodes and proceeded at a rate of 1.67% per each day increase in
physiological day (a day with non-limiting temperature and photoperiod). Leaf production per plant versus main
stem node number occurred in two phases; phase 1 when plant leaf number increased with a slower and densityindependent
rate (3 leaves per node), and phase 2 with a higher and density-dependent rate of leaf production (8-
15 leaves per node). A close relationship was found between the fraction of senesced leaves per plant and the
same fraction on the main stem. The average leaf size per plant increased from 4 cm2 when there were 10 nodes
on the main stem and stabilized at 10.8 cm2 when there were 21 nodes on the main stem. Plant density and
sowing date did not affect leaf size. Plant leaf area was also predictable directly from main stem node number.
The relationships found in this study can be used in simulation models of chickpea
Evaluation of the behavior of native Iranian almond species as rootstocks
Abstract: Iran is one of the most important regions for origin and diversification of wild almond species in the world. Over 20 species, naturally distributed in many regions, have been identified to date in Iran. These can be used as rootstocks in different Prunus species such as almond or peach due to their adaptability to severe (drought) environmental conditions and resistance to some pests and diseases. Results showed that P. eburnea had the most stem biomass, and P. scoparia the least leaf area and the largest root system among the three species, which can indicate better adaptation to drought conditions. The correlations between the measured traits suggest that the relationship between shoot and root morphology is unique for each species. In addition, results indicated that P. eburnea had the highest seed germination percentage and P. elaeagnifolia the lowest. Finally, there was significant difference between wild rootstocks in grafting success, with P. scoparia and P elaeagnifolia showing the best behavior
Physiological responses of olive cultivars to salinity stress
The aim of this study was to evaluate the tolerance of seven promising olive cultivars for southern parts of Iran (âAmigdaliloliaâ, âDakalâ, âZardâ, âDezfulâ, âTokhm-e-Kabkiâ, âShirazâ, and âConservaliaâ) against salinity stress. Biochemical and physiological responses of the cultivars irrigated with saline water application (control, 4, 8, and 12 dS m-1) were evaluated and the tolerant cultivars were identified. In contrast to the tolerant cultivars, the sensitive ones continue to grow with lower rate and died under salinity stress. In general, growth indices of olive cultivars were reduced with increasing salinity stress and the lowest growth indices were obtained under 12 dS m-1 treatment. Results indicated that the accumulation of higher levels of soluble carbohydrates and proline in the leaves of the tolerant cultivars helps them to deal with salinity stress. The results showed that saline waters up to 4 dS m-1 for irrigation can be used for olive cultivars, however, based on the result of this study, it is not recommended to use water sources with higher electric conductivities to irrigate sensitive olive cultivars. We concluded that the tolerant cultivars stopped growth and used their energy to defend against the salinity stress
Electrochemical determination of the herbicide bentazone using a carbon nanotube b-Cyclodextrin modified electrode
An electrochemical sensor has been developed for the determination of the herbicide bentazone, based on a GC
electrode modified by a combination of multiwalled carbon nanotubes (MWCNT) with b-cyclodextrin (b-CD) incorporated
in a polyaniline film. The results indicate that the b-CD/MWCNT modified GC electrode exhibits efficient
electrocatalytic oxidation of bentazone with high sensitivity and stability. A cyclic voltammetric method to determine
bentazone in phosphate buffer solution at pH 6.0, was developed, without any previous extraction, clean-up,
or derivatization steps, in the range of 10â80 mmolL 1, with a detection limit of 1.6 mmolL 1 in water. The results
were compared with those obtained by an established HPLC technique. No statistically significant differences being
found between both methods
The individual and combined effects of obesity- and ageing-induced systemic inflammation on human skeletal muscle properties.
BACKGROUND/OBJECTIVES: The purpose of this study was to determine whether circulating pro-inflammatory cytokines, elevated with increased fat mass and ageing, were associated with muscle properties in young and older people with variable adiposity. SUBJECTS/METHODS: Seventy-five young (18-49 yrs) and 67 older (50-80 yrs) healthy, untrained men and women (BMI: 17-49âkg/m(2)) performed isometric and isokinetic plantar flexor maximum voluntary contractions (MVCs). Volume (Vm), fascicle pennation angle (FPA), and physiological cross-sectional area (PCSA) of the gastrocnemius medialis (GM) muscle were measured using ultrasonography. Voluntary muscle activation (VA) was assessed using electrical stimulation. GM specific force was calculated as GM fascicle force/PCSA. Percentage body fat (BF%), body fat mass (BFM), and lean mass (BLM) were assessed using dual-energy X-ray absorptiometry. Serum concentration of 12 cytokines was measured using multiplex luminometry. RESULTS: Despite greater Vm, FPA, and PCSA (P0.05), while IL-8 correlated with VA in older but not young adults (râ©Ÿ0.378, Pâ©œ0.027). TNF-alpha correlated with MVC, lean mass, GM FPA and maximum force in older adults (râ©Ÿ0.458; Pâ©œ0.048). CONCLUSIONS: The age- and adiposity-dependent relationships found here provide evidence that circulating pro-inflammatory cytokines may play different roles in muscle remodelling according to the age and adiposity of the individual.International Journal of Obesity accepted article preview online, 29 August 2016. doi:10.1038/ijo.2016.151
Performance-based design optimization using uniform deformation theory: a comparison study
Identification of self-incompatibility genotypes and DNA fingerprinting of some Australian almond cultivars
The original publication is available at www.actahort.orgThe origin of Australian almond cultivars is mostly unknown and therefore the aim of this study is to characterise them for their incompatibility groups and their genetic diversity. The self incompatibility (SI) genotypes of 25 Australian almond (Prunus dulcis) cultivars were determined by PCR analysis of genomic DNA using a combination of specific primers based on the intron regions and primers based on the conserved regions of Rosaceous S-RNase genes. DNA fingerprinting of the cultivars was achieved through microsatellite fragment analysis and comparison with European and American cultivars, to determine the genetic diversity within Australian almond accessions. Results showed a diverse range of incompatibility groups within Australian cultivars and fingerprinting reflected their ancestry, a combination of American and European backgrounds. A germplasm collection has been established for conservation and further characterisation of local cultivars.M. Wirthensohn, M. Rahemi and A. FernĂĄndez i MartĂhttp://trove.nla.gov.au/work/16356668
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