Effects of smoke,ash and heat shock on seed germination of seven species from Central Zagros rangelands in the semi-arid region of Iran

Fire products have been widely identified as germination cues for a number of species from both fire-prone and fire-free ecosystems. However, there is uncertainty about the effects of fire products on seed germination of semi-arid rangeland species. We examined the germination of seven dominant species from Central Zagros rangelands in the semi-arid region of Iran under various heat shock (60, 80 and 120 °C), aerosol smoke, ash and control treatments. Our findings showed that fire products could enhance, inhibit or not affect the seed germination of rangeland species in this area. The germination percentage of Astragalus adscendens increased following 60 °C heat treatment in comparison with the control. The germination of Astragalus verus, Bromus tectorum, B. tomentellus and Phlomis olivieri were increased significantly using smoke treatment (P<0.0001). The seed germination of B. tomentellus and B. tectorum was promoted by ash treatment, whereas the other species exhibited no response or were inhibited by fire products. In addition, smoke treatment shortened the overall germination time of B. tectorum. These findings suggest that fire products affect the germination of several species and can serve as potential tools for understanding the vegetation dynamics and restoration of disturbed semi-arid rangelands.     

Influence of NaCl salinity on some physiological aspect of strawberry cv. Camarosa

One of the most important elements affecting the growth and development of a plant is salinity. Therefore, to evaluate the effect of salinity on some physiological aspect of Strawberry (Fragaria x ananassa Duch.) plants cv. Camarosa, a greenhouse experiment was conducted at Vali-e-Asr University of Rafsanjan in 2009. This study was carried out as Factorial experiment based on RCD design with 4 replications to determine the influence of salinities (0, 30, 60 and 9 mMol.L-1) on proline, soluble sugars content, chlorophyll a (CHLa), chlorophyll b (CHLb), total chlorophyll (TC), Spad and chlorophyll florescence. Results indicated that fresh leaves tissue were used to measure proline, soluble protein and soluble sugars content, CHLa, CHLb, TC. Salinity treatment significantly increased proline content, soluble sugars while chlorophyll a (CHLa), chlorophyll b (CHLb), Spad and chlorophyll florescence significantly decreased. Nine day after NaCl exposure, Fv/Fm and Spad in 60 and 90 mM NaCl were significantly lower than control. It was concluded that this cultivar of strawberry may uses osmoregulation by increasing proline and soluble sugars level in order to tolerate salinity conditions.     

Effect of in vitro exposure to Vibrio vulnificus on hydroelectrolytic transport and structural changes of sea bream (Sparus aurata L.) intestine

The everted gut sac technique has been used to investigate the effect of Vibrio vulnificus on water and electrolyte (Na⁺, K⁺, Cl⁻, HCO₃ ⁻) transport on the intestine of sea bream (Sparus aurata L.). Both the anterior and the posterior intestine were incubated in a medium containing 10⁸ V. vulnificus cells ml⁻¹ at 25°C for 2 h. The presence of V. vulnificus resulted in a significant reduction (P < 0.05) of water absorption in the anterior intestine, while sodium absorption in the anterior (P < 0.01) and posterior (P < 0.05) intestine was elevated. Chloride absorption was increased, but the changed was not significant, while potassium absorption decreased significantly (P < 0.05), but only in the posterior intestine. Incubation the sea bream intestine with V. vulnificus did not affect carbonate secretion in the anterior segment, whereas high secretion was stimulated in the posterior segment (P < 0.01). Histological evaluations demonstrated damage in the anterior intestine of sea bream that was characterized by the detachment of degenerative enterocytes, alterations in the microvilli, and the presence of a heterogenous cell population, indicating inflammation. Based on our results, we conclude that V. vulnificus caused cell damage to the intestine of sea bream and that the anterior intestine is more susceptible than the posterior part of the intestine. Several hypotheses are suggested to explain our observations, such as the presence of higher numbers of villosities in the anterior intestine than in the posterior one and/or the presence of endogenous bacteria in the posterior intestine which may have a protector role.     

Study of male effect on feeding and estrus behavior of Afshari ewes

Tropical Animal Health and Production - This study was conducted to evaluate the male effect on the manifestation of estrus and feeding behavior of Afshari ewes during their breeding season. The...     

不同改良措施对沙质土壤颗粒组成及分形特征的影响

【目的】研究不同改良措施下沙质土壤质地变化,为沙化土壤改良提供科学依据。【方法】以新疆南疆典型沙化土壤为研究对象,设置5种不同改良措施(种植燕麦(A₁)、种植油菜+燕麦(A₂)、种植燕麦+油菜秸秆翻耕+生物菌肥(A₃)、种植燕麦+农家肥(A₄)、种植燕麦+农家肥+生物菌肥(A₅)),采用田间试验,分析不同改良措施对沙化土壤颗粒组成分形的影响。【结果】不同改良措施下土壤分形维数D值介于2.35～2.49,与对照相比,随着土层的加深,土壤的细颗粒物质的分形维数值呈增加趋势;土壤颗粒分形维数D值与黏粒呈极显著正相关,与细粉粒呈显著正相关,与砂粒呈显著负相关。【结论】农家肥或绿肥与生物菌肥配合施用,可有效改善沙化土壤的理化性状。     

Characterizing Groundwater Dynamics Based on Impact of Pulp and Paper Mill Effluent Irrigation and Climate Variability

Automated synoptic weather typing and robust orthogonal stepwise regression analysis (via principal components analysis) were applied together to develop within-weather-type air pollution prediction models for a variety of pollutants (specifically, carbon monoxide – CO, nitrogen dioxide – NO₂, ozone – O₃, sulphur dioxide – SO₂, and suspended particles – SP) for the period 1974–2000 in south-central Canada. The SAS robust regression procedure was used to limit the influence of outliers on air pollution prediction algorithms. Six-hourly Environment Canada surface observed meteorological data and 6-hourly US National Centers for Environmental Prediction (NCEP) reanalysis data of various weather elements were used in the analysis. The models were developed using two-thirds of the total years for meteorological and air pollution data; the remaining one-third (randomly selected) was used for model validation. Robust stepwise regression analysis was performed to analytically determine the meteorological variables that might be used to predict air pollution concentrations. There was a significant correlation between observed daily mean air pollution concentrations and model predictions. About 20, 50, and 80% of the 80 prediction models across the study area possessed R ² values ≥ 0.7, 0.6, and 0.5, respectively. The results of model validation were similar to those of model development, with slightly smaller model R ² values.     

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.