Emergence of irrigated cotton in flatland planting in relation to furrow opener type and crust-breaking treatments for Cambisols in central Iran

Emergence of cotton (Gossypium hirsutum L.) under flatland mechanized planting system with crust-forming soil and saline soil and irrigation water can be suboptimal in central Iran. A field experiment was conducted to determine furrow opener type and crust-breaking method effects on cotton emergence on a silty clay soil (Calcic Cambisols). The effects of five planters (equipped with runner, single- and double-disk type openers) and five crust-breaking methods (using rolling cultivator, rolling-type crust breaker, spike-tooth, chain-type harrows and no crust-breaking) on the seedling emergence were studied. The results showed that planter type significantly affected cotton seedling emergence. In non-crust-breaking method, the best emergence was produced with the double-disk opener planter that created crack lines along the seed rows. This phenomenon was not observed with the runner-type opener planter. However, some crack lines were observed on the outside edges of its smooth-crown zero-pressure press wheels tires, which resulted in large clod formation after crust-breaking and had therefore negative effect on seedling emergence. Crust-breaking had negative effect on final emergence for double-disk planter due to filling the crack lines with loosened soil. Crust-breaking improved emergence percentages for runner opener planters, when the depth of penetration of the crust breaker teeth was shallow. The conclusion is that irrigated cotton emergence on crust-forming soils in a flatland planting system might significantly be improved by selecting a double-disk planter with zero-pressure press wheel tires without any crust-breaking operation under the soil and climate of central Iran.     

Impacts of long-term application of buctril super (bromoxynil) herbicide on microbial population,enzymes activity,nitrate nitrogen,Olsen-P and total organic carbon in soil

Long-term impact of buctril super (bromoxynil) herbicide in the wheat fields on soil microbial population, nitrate-N, Olsen-P, total organic carbon (TOC) and enzyme activities was evaluated in 18 sites in Pakistan. Nine sites were randomly selected from those places where bromoxynil herbicide had been used for the last 10 years designated as soil ‘X’ and other nine where no herbicide was used in that period designated as soil ‘Y’. Very importantly, it was found that long-term application of this herbicide in wheat fields reduced the actinomycetes and fungi population up to 19.7 and 14.3%, respectively, urease and dehydrogenase activity by 17.5 and 28.2%, respectively, and reduced nitrate-N, Olsen-P and TOC up to 55, 17 and 28.57%, respectively. Presence of high clay and organic matter contents enhanced the detrimental effect of herbicide by prolonging its persistence as compared to light-textured soils with low organic matter. As in Pakistan this herbicide is being used most frequently in wheat fields, data are scarce on the long-term effect of this herbicide on soil microbial activities and soil health. These findings could give new insights about the use of alternate herbicide in wheat fields, particularly in clay-textured and high organic matter contained soils for maintaining soil health.     

Approaches for developing molecular markers associated with virus resistances in potato (Solanum tuberosum)

Journal of Plant Diseases and Protection - Potato, (Solanum tuberosum), is one of the most common and important food sources for humans. It is not only essential as a food source but also has many...     

Expression and Purification of Neurotoxin-Associated Protein HA-33/A from Clostridium botulinum and Evaluation of Its Antigenicity

Background: Botulinum neurotoxin (BoNT) complexes consist of neurotoxin and neurotoxin-associated proteins. Hemagglutinin-33 (HA-33) is a member of BoNT type A (BoNT/A) complex. Considering the protective role of HA-33 in preservation of BoNT/A in gastrointestinal harsh conditions and also its adjuvant role, recombinant production of this protein is favorable. Thus in this study, HA-33 was expressed and purified, and subsequently its antigenicity in mice was studied. Methods: Initially, ha-33 gene sequence of Clostridium botulinum serotype A was adopted from GenBank. The gene sequence was optimized and synthesized in pET28a (+) vector. E. coli BL21 (DE3) strain was transformed by the recombinant vector and the expression of HA-33 was optimized at 37°C and 5 h induction time. Results: The recombinant protein was purified by nickel nitrilotriacetic acid agarose affinity chromatography and confirmed by immunoblotting. Enzyme Linked Immunoassay showed a high titer antibody production in mice. Conclusion: The results indicated a highly expressed and purified recombinant protein, which is able to evoke high antibody titers in mice. Key Words: Botulinum neurotoxin, Expression, Purification     

Optimization of polymerization conditions and thermal degradation of conducting polypyrrole coated polyester fabrics

PET fabric is coated with conducting polypyrrole (PPy) by oxidative polymerization from an aqueous solution of Py using ferric chloride hexahydrate (FeCl₃) as oxidant and p-toluene sulphonate (pTSA) as dopant. The optimum concentrations for Py, FeCl₃ and pTSA were found to be 0.11, 0.857 and 0.077 mol/l respectively, which yielded a conductive fabrics with resistivity as low as 72 Ω/sq. PPy fabric gained resistivity less than one order of magnitude when aged for 18 months at room temperature. The stabilizing effect of the dopant pTSA against thermal degradation was demonstrated; the undoped samples reached resistivity of around 40 kΩ, whereas doped samples reached less than 2 kΩ at the same temperature and time.     

新疆天山一号冰川地衣地理区系与生态特征

初步整理了分布在天山一号冰川的地衣种类,共5目12科24属51种.地衣区系上包括世界广布种、环极北极高山种、环极低北极及北方种、环北方种、两极和大西洋种、温带种、东亚种、东亚-北美西部、北欧-巴基斯坦-北美种、中亚分布种、北半球大陆广布种、两半球广布种、中国特有种等.同时结合地衣的生长环境特征将该地区的地衣分藓丛生、土生、草地生、地面生、石浮土生、岩面生、荒漠风滚、树皮或树枝生、朽木生地衣种等9种生态类型.     

Relationship between rhizosphere acidification and phytoremediation in two acacia species

Purpose

Phytoremediation is the most sustainable and economical strategy for reclamation of the salt-affected soils. In order to investigate the relationship between phytoremediation and rhizosphere acidification, two experiments (greenhouse and field) were conducted using two acacia species viz. Acacia ampliceps and Acacia nilotica.

Materials and methods

In greenhouse experiment, both the species were exposed to 100 and 200 mM NaCl concentrations in solution culture. The release of organic acids from plant roots was determined after 14 and 28 days of the salt treatment. Shoot and root ash alkalinity was determined after harvesting the plants. In field experiment, both the species were grown on a saline sodic soil for 2 years. After every 6 months, plant growth data were recorded and soil samples were collected from different soil depths for physicochemical analyses.

Results and discussion

The results of greenhouse study indicated higher rhizosphere acidification by A. ampliceps than A. nilotica in terms of release of citric acid, malic acid, and tartaric acid along with ash alkalinity. The comparison of both the species in the field indicated higher amelioration in the soil properties like pH_s, EC_e, SAR, bulk density, and infiltration rate by A. ampliceps than A. nilotica.

Conclusions

It is concluded from these studies that A. ampliceps is more suitable species than A. nilotica for the phytoremediation of the salt-affected soils due to its higher rhizosphere acidification potential.

     

The effect of feeding diets containing deoxynivalenol contaminated corn on channel catfish (Ictalurus punctatus) challenged with Edwardsiella ictaluri

Channel catfish were fed practical corn‐soybean meal diets for 10 weeks that contained various weighed amounts of ground, dried field corn contaminated with 20 mg deoxynivalenol (DON) kg⁻¹. Weighed amounts of DON corn were blended with weighed amounts of ground, clean corn that contained no DON (0 mg kg⁻¹) to yield five diets that had 0, 2.5, 5.0, 7.5 and 10.0 mg DON kg⁻¹ of diet. Results show that catfish fed diets that contained DON for 7 weeks did not experience lower weight gains or poorer feed conversion ratios that were significantly (P > 0.05) different from control‐fed fish. Mortality of catfish during the 21‐day post‐challenge period indicate that catfish fed diets containing DON‐contaminated corn that provided at least 5.0 mg DON kg⁻¹ of diet had significantly (P < 0.05) lower mortality than catfish fed the control diet or the diet that provided 2.5 mg DON kg⁻¹ of diet. The presence of DON‐contaminated corn in the experimental diets did not significantly (P > 0.05) alter fish body weight gains and appeared to provide a protective effect for channel catfish challenged with the pathogenic bacterium Edwardsiella ictaluri.     

Supplemental graded levels of neutral phytase using pretreatment and spraying methods in the diet of grass carp,Ctenopharyngodon idellus

A feeding trial was conducted for 8 weeks to evaluate the effects of graded levels of neutral phytase supplementation using pretreatment or spraying method on growth performance, body composition, bone mineral content and serum biochemical parameter in grass carp, Ctenopharyngodon idellus. A control diet without phytase was added and six additional diets were arranged as a 2 × 3 factorial with two methods (pretreatment or spraying) and three levels of phytase (500, 1000 or 1500 U kg^?1). The results showed that supplemental phytase at different levels in the diet and with different application methods all improved weight gain, specific growth rate and protein efficiency ratio of grass carp (P < 0.05). The feed conversion ratio in phytase‐supplemented groups was lower than the control. Dietary phytase addition reduced the lipid content in the whole body of grass carp. Phytase supplementation with different method increased ash and mineral (P, Ca, Mg and Zn) contents in whole‐body and vertebra (P < 0.05). The increase in these mineral contents was also observed in the serum. Based on the results, we may conclude that: 1) supplemental dietary phytase, regardless of the application methodology, improved the growth performance and nutrient utilization in grass carp; 2) the pretreatment mode of phytase application was more effective than spraying at the same phytase level.     

Combined application of biochar with compost and fertilizer improves soil properties and grain yield of maize

A pot study was conducted to assess the combined effect of biochar (B) with compost (Com) and inorganic fertilizers (F) for improving nutrient acquisition and productivity of maize. Seven different treatments, including B (1% w/w), F (Recommended nitrogen, phosphorus and potassium (NPK): 60, 30 and 25 mg kg^─1), Com (1.5% w/w), Com+F (1.5% + NPK), B+F (1% + NPK), B+Com (0.5% + 0.75%), B+Com+F (0.5% + 0.75% + NPK) along with a control (C) without B, Com and F were applied in pots with four replications. The results showed that growth and grain yield of maize increased by the application of B, Com and F compared with C, but B+Com+F was more effective than their sole application (i.e. B, Com and F). Highest leaf chlorophyll content, gas exchange attributes and nutrient concentrations: N, P and K in shoot and grains were observed, where B+Com+F was applied followed by Com+F > B+F > B+Com > F > Com > B > C. Soil properties such as soil organic carbon (SOC), N, P, and K were significantly increased, whereas soil pH was decreased by the combination of B with Com and F. Hence, application of B in combination with Com and F (B+Com+F) could be a good management strategy to enhance crop productivity and improve soil properties.