Spatial variability of soil microbial indices in common alder COMMON ALDER(Alnus glutinosa) stands using a geostatistical approach in northern Iran

Microbial indices and their spatial patterns are strongly affected by environmental factors. Spatial variability of soil properties is one of the most important causes of variability in soil microbial indices. This research was conducted in the Caspian forest to assess spatial variabilities and frequency distributions of microbial properties.Ninety soil samples were taken using a grid sampling design 40 9 40 m. Microbial indices, organic carbon,nitrogen and pH were determined. Soil variable distributions showed that microbial indices had abnormal distributions. Logarithmic transformation produced normal distribution. Spatial continuity using geostatistical(variogram) was studied and maps obtained by point kriging.The variograms revealed the presence of spatial autocorrelation. The results indicate that spatial dependence of soil microbial indices was affected by non-intrinsic factors and forest management procedures. The maps show that soil microbial indices and soil properties have spatial variability. The spatial pattern of microbial indices was correlated to organic carbon and nitrogen.     

Effects of forest harvesting on runoff and sediment characteristics in the Hyrcanian forests,northern Iran

Loss of canopy cover by forest harvesting generally increases the average surface runoff volume and sediment. Selective cutting (single and group selection method) is the most usual forest harvesting method in the Hyrcanian forests in the north of Iran. The purpose of this study is to find the effect of selective logging technique on the hydrological behavior of runoff and sediment in the Kheyrud forests located in northern Iran over 1 year. Four treatments were implemented: natural forest without harvesting (C), forest with selective harvesting (H) and area without canopy cover (WC) and skid trail (S). Three types of data were measured in each plot including soil chemical and physical properties, runoff and sediment load after each rainfall. The results indicate significant differences (P ≤ 0.05) in runoff generation and sediment production with respect to the treatments cover. The runoff in all treatments showed relatively similar response to rainfall, while the highest runoff and sediment were observed in skid trails, and the area without canopy cover (1.13 and 0.62 mm, and 1.2 and 0.51 g m^?2), averagely. In contrast, the natural forest without harvesting and the forest with selective harvesting treatments exhibited the lowest amounts of runoff (0.2 and 0.44 mm) and sediment (0.1 and 0.17 g m^?2), averagely. Implementation of low logging technique was useful to control the effects of logging on the runoff and sediment yield.     

Preference and performance of <Emphasis Type="Italic">Plutella xylostella</Emphasis> (L.) (Lepidoptera: Plutellidae) on canola cultivars

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important insect pest of canola, Brassica napus L., in Ardabil, Iran. Host plant resistance is an essential component of integrated management of P. xylostella. We investigated the preferences and performance of P. xylostella on nine commercial cultivars of canola, namely Zarfam, RGS003, Adder, Okapi, Opera, Hyola401, Ebonite Option500 and Elite under greenhouse conditions at 23 ± 1°C, 50 ± 5% RH and 14L:10D. In free-choice situation, oviposition was lowest on Opera (23.5) and highest on Zarfam (44.7). In the life table study, fecundity of new generation female moths was lowest on Opera (95.4) and highest on Adder (145.7). Survival from egg to adult was significantly lower on Opera, Option500 and Hyola401 than on other tested cultivars. The intrinsic rate of natural increase (r _m) and population growth rate (λ) were lowest on Opera and highest on Zarfam. The generation time (T) was shortest on Zarfam (17.2 days) and longest on Hyola401 (19.9 days) whereas doubling time (DT) was longest on Opera (3.9 days) and shortest on Zarfam (3.0 days). Our results clearly suggest that Opera was the most resistant host among the tested cultivars and has the potential to be used in the integrated management of P. xylostella.     

Effects of carbohydrate source and polyethylene glycol on maturation and germination of somatic embryos in walnut (<Emphasis Type="Italic">Juglans regia</Emphasis> L.)

Low efficiency of somatic embryo maturation, germination, and conversion to plantlets is a major problem in many species including J. regia L. Germination efficiency of somatic embryos is very low in walnut. In this study, effects of two carbohydrate sources, sucrose and maltose (each at 3% and 6%), and two kinds of PEG (4000 and 6000) (each at four levels of 1.5%, 3%, 5% and 7.5%) on maturation and germination of walnut embryos were tested. The number of somatic embryos increased conspicuously on medium containing PEG. Furthermore, higher levels of PEG-4000 (7.5%) could remarkably enhance the morphogenesis of somatic embryos and the number of embryos produced. PEG-4000 stimulated somatic embryo maturation of walnut. This stimulatory effect was dependent on the carbohydrate source used. Sucrose in combination with PEG-4000 produced 50% of cotyledonary and normal somatic embryos. Different concentrations of PEG were effective on the number of embryos with a shoot meristem. PEG-4000 7.5% and sucrose 3.0% produced the highest rate (50.0%) of normal shooting embryos. However, PEG (4000, 6000) and maltose caused an unfavorable effect and increased the frequency of abnormal shaped somatic embryos.     

Enhancing Seed Germination Rate of Four Turfgrass Genera by Acid Treatments

Turfgrasses are commonly propagated by seeds. In some genera of turfgrasses, the presence of low germination percentage (GP) or rate is the main problem in seed propagation. The present investigation was undertaken to determine the best concentration and duration of sulphuric acid treatment for seeds of the following turfgrass genera: Cynodon dactylon [L.] Pers.; Festuca rubra L. var. rubra‘Shadow’; Lolium perenne L. ‘Barball’ and Poa pratensis L. ‘Merion’. In the first experiment, sulphuric acid was used with concentrations of 0 (control), 25, 50, 75 and 100 % for 10, 15, 20, 25 and 30 min. In the second experiment, effects of light/dark (16/8) or dark conditions on germination rates of different mentioned genera were investigated using the best specific acid treatments. Each treatment was replicated four times with 100 seeds per replicate kept in plastic Petri dishes. The results indicated that in Cynodon, using 50 % acid for 20–25 min had highest GP and mean daily germination (MDG) in light/dark; in Festuca, using 25 % acid for 15 min had highest GP and MDG in light/dark; in Lolium using 50 % acid for 10 min had highest MDG in dark and in Poa, using 50 % acid for 15–25 min had highest MDG in dark. Both Cynodon and Poa had the highest and Festuca had the lowest GPs. Cynodon and Festuca had the highest and lowest MDGs, respectively. This simple procedure, with considerable results, may be replaced to time-consuming and expensive methods such as seed priming.     

Effects of humic acid on remediation of the nutritional deficiency of gerbera in hydroponic culture

Information is scant on the effect of humic acid (HA) on physiological, antioxidant and photosynthesis attributes of gerbera plants undergoing nutrient deficiency in culture solution. Gerbera plants cv. Malibu were grown in a factorial experiment based on a completely randomized design with 3 replications, using 3 different nutrient solutions [complete nutrient solution (NSc), 25% NSc (NS1), and 50% NSc (NS2)] treated with 2 levels of humic acid [0 (HA0) and 500 mg/l (HA1)].The interaction effect of HA and NS showed that HA improved the flower number in NSc, the transpiration in NS1+HA1, photosynthesis rate in NSc+HA1, stomatal conductance (gs) in NS2, mesophyll conductance of leaves in all NS levels and photosynthetic water use efficiency in NSc+HA1. The interaction effect of nutrient solution and HA on antioxidant activity was inconclusive, malondialdehyde content was the highest in NS2 and the lowest in NS1+HA1. The peroxidase activity increased in complete nutrient solution with and without HA and there were no differences among other treatments. Superoxide dismutase activity increased in NS1 and complete nutrient solution with HA and reached the highest in NSc. Humic acid was more effective in nutrient uptake, i.e., nitrogen, phosphorus, potassium, calcium, zinc, and iron (N, P, K, Ca, Zn, and Fe) in complete nutrient solution compared to NS1 and NS2. Conclusively, humic acid can compensate the nutrient deficiency stress of the culture solution in regards to protein synthesis, photosynthesis attributes regardless of the nutrient uptake of gerbera.     

Medium-term seed storage of 50 genera of forage legumes and evidence-based genebank monitoring intervals

Genebanks maintaining seeds for long-term genetic resources conservation monitor seed lots to detect early loss in viability. Monitoring is costly and depletes valuable seed. Three decades of genebank seed germination test results of diverse forage species from 50 legume genera in the International Livestock Research Institute’s medium-term store (circa 8 °C with 5% moisture content) were analysed to determine whether advice on seed monitoring intervals could be derived. Cumulative normal distributions were fitted by probit analysis for each seed lot and compared within each genus. Six patterns of within-genus variation were identified: no detectable trend in germination test results during storage (4 genera); detectable trends, but variable (positive to negative) amongst lots (5); consistent slope of loss in viability amongst lots (17); consistent slope of increase in ability to germinate amongst lots (21); common loss in viability amongst lots (2); common increase in ability to germinate amongst lots (1). Seed lot monitoring intervals for the medium-term store were derived for each of 19 genera with consistent loss in viability across seed lots: three genera provided comparatively rapid deterioration, five met the general expectations for a medium-term store (2–10 years’ maintenance of high viability), whilst 11 provided much better survival. Moreover, 26 further genera provided no evidence as yet of seed deterioration; of these, 22 improved in ability to germinate during storage indicating confounding of hardseededness with viability in germination tests.     

EFFECT OF NITROGEN SOURCES AND RATES ON YIELD AND QUALITY OF SILAGE CORN

The objective of this study was to determine the effect of nitrogen (N) application source and rate on silage corn (Zea mays L.). Urea, ammonium nitrate, and ammonium sulfate were compared at 50, 100, 150, and 200 kg N ha^?1. The application of ammonium sulfate produced the highest plant height, leaf area index (LAI), total yield, and stem, leaf, and ear dry matter, followed by ammonium nitrate and urea. However, nitrogen sources had no marked effects on the content of protein, ash, oil, soluble carbohydrates, acid detergent fiber (ADF) and neutral detergent fiber (NDF). As the rate of nitrogen increased plant height, LAI, total yield, and stem, leaf, tassel, and ear dry matters, and protein, ash and oil contents increased while soluble carbohydrates, ADF, and NDF contents decreased. Ammonium sulfate was the most effective N source on production and 200 kg N ha^?1 was the most effective N rate on corn yield and quality.     

A Green Approach for the Biosynthesis of Gold Nanoparticles Using Cuminum cyminum L. Seed and Its Application for Pain Management in Rats

Background:This study investigated the antinociceptive effect of cumin and its biosynthesized AuNPs. Methods:Cumin extract (E) and cumin-AuNPs (GN) were prepared and administered intraperitoneally at the concentrations of 200, 500, and 1000 mg/ml to 27 male rats. UV–Vis spectroscopy and AFM were applied for AuNPs synthesis confirmation. The nociceptive behavior was assessed, and IL-6 serum levels were measured. Results:Cumin-AuNPs showed a peak absorption of 515 nm, and a size of about 40 nm. Three different concentrations of extract had no significant effect on acute and chronic nociceptive behavior. GN + E200 (46.00 ± 10.59) showed a significant acute anti-nociceptive effect compared to the control (98.66 ± 4.91; p = 0.029) and SS300 (98.33 ± 20.30; p = 0.029) groups. Also, GN + E500 (42.00 ± 11.84) significantly reduced acute nociceptive behavior compared to the control (98.66 ± 4.91; p = 0.019), SS300 (98.33 ± 20.30; p = 0.020), and GN + E1000 (91.00 ± 26.00; p = 0.040) groups. IL-6 serum levels reduced significantly in GN + E500 (24.65 ± 10.38; p = 0.002) and SS300 (33.08 ± 1.68; p = 0.039) compared to the controls (46.24 ± 3.02). Chronic nociceptive behavior was significantly lower in the SS300 (255.33 ± 26.30) compared to E200 (477.00 ± 47.29; p = 0.021), E500 (496.25 ± 46.29; p = 0.013), and GN + E500 (437.00 ± 118.03; p = 0.032) groups. Conclusion: Our findings suggest the potential effects of cumin-AuNPs on formalin-induced nociceptive behavior, which is independent of IL-6serum levels.Key Words: Interleukin-6, Pain, Cuminum cyminum L., Gold Nanoparticles, Green Synthesis     

Radiosensitivity and repair kinetics of gamma-irradiated leukocytes from sporadic prostate cancer patients and healthy individuals assessed by alkaline comet assay

Background: Impaired DNA repair mechanism is one of the main causes of tumor genesis. Study of intrinsic radiosensitivity of cancer patients in a non-target tissue (e.g. peripheral blood) might show the extent of DNA repair deficiency of cells in affected individuals and might be used a predictor of cancer predisposition. Methods: Initial radiation-induced DNA damage (ratio of Tail DNA/Head DNA), dose-response curves and kinetics of DNA repair in leukocytes from healthy volunteers and prostate cancer patients were assessed using alkaline comet assay after exposure to ⁶⁰Co gamma rays. Results: Results showed that higher levels of baseline and gamma rays induced DNA damage in leukocytes of prostate cancer cases than in controls. A similar dose response was obtained for both groups. After a repair time of 24 h following in vitro irradiation, samples from the healthy individuals showed no residual DNA damage in their leukocytes, whereas prostate cancer patients revealed more than 20%. Although similar initial radiosensitivity was observed for both groups, the repair kinetics of radiation induced DNA damage of leukocytes from prostate cancer cases and healthy subjects were statistically different. Conclusion: These results support the hypothesis that men affected by prostate cancer may have a constitutional genomic instability. Key Words: Leukocytes, DNA damage, Radiosensitivity, Prostate cancer, Comet assay