Symptoms and fungi associated with elm trees decline in Iran

Elm (Ulmus, Ulmaceae) is one of the most popular and important trees in urban and landscape areas in Iran. A severe decline of elm trees has recently been observed in some areas of Kerman and Shiraz cities. However, the identity of the causal agents has not yet been investigated. The purpose of this study, carried out in the years 2012–2014, was to isolate and identify fungal trunk pathogens associated with decline symptoms observed in elm trees. Samples were collected from trunks and branches of trees showing various disease symptoms and internal wood lesions. Fungal isolations were made from discolored or decayed wood tissue. In Kerman some elm trees were attacked by the beetle Aeolesthes sarta; therefore, samples were also collected from larvae and adults of beetles associated with trees showing wood damage. Fungal isolates were identified by morphological, cultural and molecular characteristics. Thirteen fungal species, Phaeoacremonium (P.) minimum, P. parasiticum, P. sicilianum, P. alvesii, P. fraxinopennsylvanicum, Spencermartinsia viticola, Dothiorella (Do.) sarmentorum, Neoscytalidium hyalinum, Diatrype (Di.) whitmanensis, Cosmospora viridescens, Phoma (Pho.) herbarum, Phellinus (Phe.) tuberculosus and Inonotus levis were identified. Phaeoacremonium parasiticum was the only species isolated from both larvae and adult beetles. Pathogenicity trials were performed on detached shoots of elm under greenhouse conditions. Dothiorella sarmentorum was the most virulent species based on the length of wood necrosis. This study is the first report of P. sicilianum, C. viridescens and Phe. tuberculosus in Iran. In addition, most of the isolated species are reported for the first time on elm trees in the world.     

Physiological responses of pepper plant (Capsicum annuum L.) to drought stress

Water shortage is the most important factor constraining agricultural production all over the world. New irrigation strategies must be established to use the limited water resources more efficiently. This study was carried out in a completely randomized design with three replications under the greenhouse condition at Shahrekord University, Shahrekord, Iran. In this study, the physiological responses of pepper plant affected by irrigation water were investigated. Irrigation treatments included control [full irrigation (FI) level] and three deficit irrigation (DI) levels—80, 60, and 40% of the plant's water requirement called DI₈₀, DI₆₀, and DI₄₀, respectively. A no plant cover treatment with three replications was also used to measure evaporation from the soil surface. Daily measurements of volumetric soil moisture (VSM) were made at each 10-cm intervals of the soil column, considered as a layer. The differences between the measured VSM and the VSM in the next day and evaporation rate at the soil surface at the same layer of the bare soil with no plant cover treatment were calculated. Eventually, by considering the applied and collected water in each treatment, evapotranspiration (ET_C) and root water uptake in each layer per day were estimated. Furthermore, fruit number per plant, fresh fruit weight/day, root fresh/dry weights, shoot fresh/dry weights, root zone volume, root length and density, crop yield, and water use efficiency (WUE) were measured under different water treatments. The results showed that the maximum and minimum of all the studied parameters were found in the FI and DI₄₀ treatments, respectively. ET_C in the DI₈₀, DI₆₀, and DI₄₀ treatments were reduced by 14.2, 37.4, and 52.2%, respectively. Furthermore, applying 80, 60, and 40% of the plant's water requirement led to the reduction in crop yield by 29.4, 52.7, and 69.5%, respectively. The averages of root water uptakes in the DI₈₀, DI₆₀, and DI₄₀ treatments reduced by 17.08, 48.72, and 68.25%, respectively. WUE and crop yield also showed no significant difference in the FI and DI₈₀ treatments. Moreover, in the DI₈₀ treatment, the reduced rate of water uptake was less than the reduced rate of plant's applied water. According to these results, it can be concluded that 20% DI had no significant reduction on the yield of pepper, but above this threshold, there was an adverse effect on the growth and yield. Therefore, for water management in the regions with limited water resources, rate of plant's applied water can be decreased by around 20%.     

The Effects of Cow Manure and Vermicompost on Availability and Desorption Characteristics of Zinc in a Loamy Calcareous Soil

The application of organic fertilizers in soils not only increases soil organic matter but also introduces essential nutrients to soil. Therefore, applying these fertilizers can affect the availability and desorption characteristics of nutrients. The main objective of this research is to study the effects of cow manure (CM) and vermicompost (VC) on availability and desorption characteristics of zinc (Zn) in a loamy calcareous soil. In this study, concentration of available Zn (using DTPA-TEA, AB-DTPA, and Mehlich 3) and desorption characteristics of Zn (using successive extraction with DTPA-TEA For 1–504 h at 25 ± 1°C) in amended soil with 0, 0.5, and 1% (w/w) of CM and VC were investigated in a completely randomized design. Results of this research showed that concentration of Zn extracted by using three methods was higher in amended soils with 1% CM and VC than those with 0.5% of these fertilizers. Furthermore, the difference between concentration of available Zn in amended soils with CM and VC was not found to be significant (p > 0.05). The results of kinetics study illustrated that the effect of organic fertilizers on Zn desorbed after 504 h was found to be significant (p < 0.01). Amount of cumulative of Zn desorbed in amended soils was significantly (p < 0.05) higher than unamended soil. Concentration of Zn desorbed after 504 h in 0.5 and 1% of CM and VC compared with unamended soil increased 26, 54, 12, and 46%, respectively. In addition, Zn desorption rate in amended soils with CM was higher than those with VC. It can be concluded that organic fertilizers applied to loamy calcareous soils enhance source of available Zn for the plant. Moreover, the results of this study showed that the ability of amended soils with VC to supplying Zn for plants was lower than those with CM.     

Fire-retarding properties of nano-silver in solid woods

Fire-retarding properties of 200?ppm nano-silver solution, with a size ranging from 20 to 80?nm, on five woody species were studied and compared with Borax and Celcune ^? . Blocks of 150?×?130?×?9?mm3 were prepared and divided into four groups of control samples, nano-silver-, Borax-, and Celcune-impregnated specimens. A special apparatus was designed, and six fire-retarding properties of each specimen were measured, namely ignition, glowing, back-darkening and back-holing times, as well as length and width of burning. Results showed that all three kinds of treatments had improving effects on the fire-retarding properties. Celcune showed the best improvement on glowing time. Cluster analysis showed direct relation between density and fire-retardant properties; also, fire-retarding behaviors of the four hardwoods were quite different to those of the one softwood. Furthermore, there are improvements in some fire-retarding properties of nano-silver-impregnated specimens that are in connection with its heat-transfer property.     

The effect of multiplex-PCR-assessed major pathogens causing subclinical mastitis on somatic cell profiles

The major pathogens causing mastitis were evaluated by multiplex-polymerase chain reaction (M-PCR) with self-designed primers in four quarters of the first, third, and fifth parities in industrial, semi-industrial, and traditional dairy cattle farms in Iran. With the incidence of infection in the quarters by Staphylococcus aureus and Streptococcus agalactiae, the mean log somatic cell count (log SCC) increased from 5.06 to 5.77. The smallest changes occurred with Escherichia coli. Contagious pathogens, when compared with environmental pathogens, were more prevalent and common and created more profound quantitative and qualitative changes in SCC profiles. The second part of the study surveyed the diversity of contaminating pathogens and their effect on quantitative and qualitative profiles of somatic cells. M-PCR was used to determine the absence (M-PCR(-)) and presence of one (M-PCR(+1)), two (M-PCR(+2)), and three (M-PCR(+3)) major pathogens in raw milk samples. Quarter log SCC increased from 5.06 (for M-PCR(-1)) to 5.5 (for M-PCR(+1)), 5.7 (for M-PCR(+2)), and 6 (for M-PCR(+3)). Percent changes in polymorphonuclears (PMNs) were not significant between different quarters and parities but were significant between different farms in terms of pathogen diversity (P?相似文献   

Single and competitive adsorption isotherms of some heavy metals onto a light textured calcareous soil amended with agricultural wastes-biochars

This study investigated the adsorption behavior of selected heavy metals (Pb, Cu, and Ni) under single and multi-metal conditions by a light textured calcareous soil amended with plant residue biochars (corn straw, wheat straw, rice husk and licorice root pulp each at 3% w/w). The Freundlich isotherm best described the heavy metal adsorption suggesting multilayer adsorption. For all treatments under both adsorption conditions, the heavy metal adsorption capacity followed the order of Pb > Cu > Ni, which was associated with the hydrolysis constant, ionic radius, and electronegativity of these metals. Simultaneous presence of multiple metals decreased the adsorption capacity for each metal and the sequence was in the order of Ni > Pb > Cu. The corn straw biochar (CSB) had the highest adsorption capacity (Freundlich K_f (mg g^?1) for Ni = 0.23, Cu = 1.41 and Pb = 2.73) and medium distribution coefficient (K_{d medium}(L kg^?1) for Ni = 59.30, Cu = 1961.00 and Pb = 2602.00), indicating the CSB is the best treatment for stabilization of heavy metals in the soil. This was associated with the chemical characteristics of the CSB (high amounts of CaCO₃ and P) and the greatest increase in soil pH value.     

Identification of acid fast bacteria from caseous lesions in cattle in Sudan

One-hundred-and-twenty caseous lesions collected from slaughtered cattle at selected slaughterhouses in Sudan were processed for the detection of acid-fast bacteria (AFB). Sixty-four of the 120 samples showed AFB on microscopic examination after staining with the Ziehl-Neelsen method. Accordingly, it was estimated that 64 (53.3%) of the 120 caseous (purulent) lesions among the samples were due to AFB whereas 56 (46.7%) were due to other causes. Growth on Lowenstein-Jensen slants was obtained in 54 of the 120 samples. The isolated AFB were tentatively identified using microscopic and cultural characteristics. Confirmation of the phenotypic clusters was achieved by analysing the mycolic acids contents and PCR-amplification of the IS6110 insertion sequences. The above two methods have allowed the identification of Mycobacterium bovis and M. farcinogenes, the major AFB isolated from cattle in Sudan. The remaining AFB, which were negative for the above two tests, were further identified by sequencing the 16S rRNA gene. The above strategy thus allowed the identification of the isolated strains as follows: 25 (46%) M. bovis; 21 (39.9%) M. farcinogenes; 4 (7.4%) M. tuberculosis; 1 (1.9%) M. avium; 1 (1.9%) Nocardia sp., 2 (3.7%) unidentified AFB. The isolation of M. farcinogenes and M. tuberculosis, from pulmonary lymph nodes represented important findings.     

Effect of Planting Geometry on the Growth and Yield Performance of Maize Intercropped with Rice

A field experiment with maize and rice planted under four planting configurations in an intercropping system was conducted to evaluate the plant competition effects on the performance of component crops. Intercropping substantially reduced grain yields of both rice and maize. Rice yield was generally low giving monocrop yield of 1,084 kg/ha. Intercropped rice ranged between 179 kg/ha and 615 kg/ha depending on maize planting arrangement. Monocrop maize yielded highest in square planting (3,617 kg/ha) and lowest in skip-row (2,600 kg/ha) planting, but planting geometry did not influence intercropped maize yield. Monocrop maize outyielded the combined yield of component crops suggesting no yield advantage through rice-maize intercropping.     

Biochemical effect of steroid anaesthesia on some liver function tests in goat

Saffan, as a type of steroid anaesthetic, was tested to demonstrate the effect of its administration on liver function in goat. For this purpose, 40 healthy animals were divided into 4 equal groups. The 1st 2 groups were given 2 or 4 mg saffan/kg body weight (B.W.), respectively. A mixture of saffan (1 mg) and xylazine (0.1 mg)/kg B.W. was given to the 3rd group. Xylazine alone was offered to the 4th group in a concentration of 0.1 mg/kg B.W. Serum samples from all groups were analysed to measure the quantities of glucose, total protein, total and direct bilirubin as well as the activity levels of transaminases. Increased glucose levels resulted from administration of saffan which evoked more hyperglycaemia than its mixture with xylazine or xylazine alone. The hyperglycaemic effect of both doses of saffan was equivocal beyond 2 hours. The effect then differed, and glucose elevation reached the 4 fold level by 2 mg saffan and the 3 fold level by 4 mg. Total serum protein, direct and total bilirubin as well as GPT and GOT were not changed in the 4 experimental groups. This was a good indication to normal liver function in the course of administration of steroid anaesthetics to goat.     

Mammary and renal excretion of chlorpromazine in goats

In experiments on goats it was found that the binding of chlorpromazine (Cpz) to the proteins in plasma and milk ranged between 91–99 and 91–97 %, respectively, and was independent of the drug concentration in the samples. The in vitro binding of chlorpromazine in whole milk (96%) was significantly higher (P<0.01) than the protein binding in skim milk (91%) because the drug was concentrated in the butterfat. The concentration of Cpz was always higher in the milk than in the corresponding plasma samples. The renal clearance of Cpz in goats with normal urine pH was very small (0.16 ml min^-1) due to the high degree of plasma protein binding and of back diffusion. The mechanisms involved during the renal excretion of Cpz in goats included glomerular filtration, probably active tubular secretion and pH dependent back diffusion.