Effect of trifluralin,pronamide, haloxyfop-p methyl,propaquizafop, and isoxaben on weed control and oilseed rape yield in Iran

In order to investigate the effect of trifluralin, pronamide, haloxyfop-p methyl, propaquizafop and isoxaben on weed control and oilseed rape yield, a two year field experiment was conducted at Darab, Iran, during 2004–2005 and 2005–2006 growing seasons. Herbicides reduced weed biomass compared with the weedy check. In 2004–2005, at 16 WAP (weeks after planting), application of trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha and trifluralin plus haloxyfop-p methyl plus isoxaben at 1200 + 100 + 500 g a.i./ha provided best control (80%) of wild mustard (Sinapis arvensis L.), compared to other treatments. At 8 and 16 WAP, wild mustard control decreased to 47 and 42%, respectively, when trifluralin was applied alone at 1400 g a.i./ha. In 2005–2006 at 16 WAP, maximum reduction in wild mustard biomass (82%) was achieved with trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha. In both years, all herbicide treatments controlled fumitory (Fumaria officinalis L.) 64–96%. In 2004–2005, at 16 WAP, wild oat (Avena fatua L.) biomass reduction by trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha was 95%. In 2005–2006, at 8 and 16 WAP, minimum biomass reduction of wild oat (37–53%) was observed with trifluralin at 1200 and 1400 g a.i./ha. In both years, at 8 and 16 WAP, the most effective herbicide treatments were trifluralin plus propaquizafop plus isoxaben and trifluralin plus haloxyfop-p methyl plus isoxaben regardless of the dose applied and provided maximum reduction in total weed biomass (77–89%) compared to other treatments. Results of both years showed that all herbicide treatments increased oilseed rape grain yield as compared with the weedy check but percentage of oil was not affected by various herbicide treatments. Maximum grain yield was obtained with trifluralin plus haloxyfop-p methyl plus isoxaben at 1200 + 100 + 500 g a.i./ha.     

Remobilization efficiency and photosynthetic characteristics of five barley (Hordeum vulgare L.) cultivars under terminal drought stress

Drought is an important limiting factor which can cause major loss in barley productivity. A field experiment was conducted to investigate the effects of irrigation regimes on assimilate remobilization and photosynthetic characteristics of five barley cultivars in 2012 and 2013. There were four levels of irrigation including well-watered [soil moisture content in root depth kept at 100% field capacity (FC)], mild drought (75% FC), severe drought (50% FC), and very severe drought (25% FC). Results showed that Karoon and Valfajr cultivars had the maximum net photosynthetic rate (P_n) ranged from 16.3 to 19.3 µmol CO₂ m^?2 s^?1 under very severe drought. Stomatal conductance (gs) was affected by drought so that Karoon and Valfajr had the lowest gs under severe and very severe drought. By improving the drought, remobilization efficiency in Karoon and Valfajr increased from 18.3% in well-watered to 54.1% under severe drought. In both years under severe and very severe drought, maximum 1000-grain weight and grain yield was obtained in Valfajr and Karoon. Overall, in arid areas, applying suitable irrigation regimes such as mild or severe drought can control soil drying, so that suitable cultivars such as Karoon and Valfajr can rehydrate overnight, and yield might not be inhibited severely.     

Complementary conservation strategies for the genus Coffea: A case study of Mascarene Coffea species

No single conservation technique can adequately conserve the full range of genetic diversity of a target species or genepool. To optimize the efficiency of germplasm conservation, a range of conservation techniques needs to be applied simultaneously. In this paper we review the progress made in the application of both in situ and ex situ complementary conservation strategies and techniques to the conservation of the genus Coffea and identify areas where more research work is required. Traditionally, Coffea species have been conserved ex situ as living plants in field genebanks due to their intermediate seed storage behaviour. However, progress made in the field of biotechnology in recent years have made it possible to envisage the use of in vitro, slow growth and cryopreservation for medium- and long-term conservation of Coffea germplasm, respectively. In situ conservation is also an important option for long-term conservation, but there are no genetic reserves specifically set up for conserving Coffea. Protected areas and managed reserves offer the best opportunities for conserving Coffea. A case study for Mascarene Coffea in Mauritius is presented and a strategy for their conservation is discussed.     

Synthesis and characterization of novel self-colored PET (polyethylene terephthalate) by step-growth polymerization containing dye based on 1,8-naphthalimide group

A novel self-colored polyethylene terephthalate (PET) was synthesized using a synthesized dye, 4-amino-N-propanoic acid-1,8-naphthalimide. For this purpose, the prepared naphthalimide dye was added upon the polycondensation step and then a self-colored PET was prepared by step-growth polymerization. The characterization of synthesized self-colored PET and naphthalimide dye were carried out using TLC, FTIR, ¹HNMR, DSC, UV-visible and Fluorometery. Results indicated that, the novel fluorescent yellow-green PET with appropriate properties was obtained. The glass transition temperature of self-colored PET was 70 °C and it was measured by differential scanning calorimeter, which revealed that addition of dye to the chains of polymer did not affect the context of glass transition of polymer. UV-visible spectrum indicated that, 99 percent of dye was incorporated in polymer chains chemically. Furthermore, the intrinsic viscosity of self-colored PET was 0.556 dl/g and molecular weight of polymer was around 35000 (g/mol) and measured using the viscometer technique.     

Dr. Abolghasem Bahrami (1894–1950): Physician,Pasteurian, and a Pioneer of Microbiology and Public Health Planning in Iran

Dr. Abolghasem Bahrami was among the generation of Iranian scientists in the early twentieth century who gained most of their knowledge through resources available inside the country. Educated at Dar-ul-Funun Medical School, he was a physician with a great talent in learning, especially self-teaching natural sciences and European languages. He joined the Pasteur Institute of Iran (IPI) at the early days of its foundation and became an integral contributor to this institution during the first twenty-five years of its mission. One of his first assignments at IPI was to help initiating an anti-rabies department by bringing back the rabies vaccine and its manufacturing equipment from Institut Pasteur of Paris. During his IPI years, aside from managerial tasks, he actively participated in upgrading the medical treatments and protocols used for controlling many infectious diseases. He functioned twice as the provisional director of IPI (1925-1926 and 1937-1946) and is considered as the first Iranian director of the Institute. Meanwhile, Dr. Bahrami was a significant contributor to the public health system and assumed several responsibilities such as Chief Quarantine Medical Officer, Chief of Public Health, and the Head of Public Health Administration, in order to improve public health planning throughout the country.Key Words: History of medicine, Iran, Microbiology, Pasteur Institute of Iran, Public health     

The correlations among serum tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and sialic acids with peripheral lymphocytes in bovine tropical theileriosis

The infection with protozoan parasite Theileria annulata induces changes triggering the activation and/or proliferation of the host lymphocytes. In order to find out the possible correlations among peripheral circulatory lymphocytes, cytokine activities and the level of sialic acids, 50 dairy Holstein cattle, naturally infected with T. annulata, were divided into 4 subgroups according to their parasitemia rates (<1%, 1–3%, 3–5% and >5%). Also, ten non-infected cattle were sampled as control group. Blood samples were taken from jugular vein into acid citrate dextrose-containing tubes for measuring hematological parameters and B and T (CD₄ and CD₈) cell populations and without anticoagulant for TNF-α, IFN-γ and sialic acid concentrations. Remarkable decreases observed in red blood cells (RBCs), white blood cells (WBCs) and packed cell volume (PCV) in infected cattle compared to healthy ones (P < 0.05). Also, with increase in parasitemia rate, total lymphocytes and monocytes alleviated in the diseased groups. By contrast, total neutrohpils and the concentrations of TNF-α, IFN-γ and total sialic acids were significantly elevated (P < 0.05) in infected animals. Accordingly, the circulatory populations of CD₄ and CD₈ T cells and B cells showed a substantial decrease, while a significant increase was observed in T (CD₄ and CD₈) cells in cattle infected with <1% parasitemia rates. Decreased circulatory T cell population shows the ineffective responses of T cells to the stimulatory cytokines such as IFN-γ or TNF-α. On the other hand, the elevation of cytokines (particularly IFN-γ) and sialic acids have presumably an inhibitory role on circulatory B cell population in infected cattle. In addition, a high level of sialic acid concentration indicates the probable role of sialic acid to regulate the parasite-host cell adhesion during sporozoites invasion.     

Regeneration and characterization of plants derived from leaf in vitro culture of two sweet orange (Citrus sinensis (L.) Osbeck) cultivars

In the current work attempts were made to investigate culture of leaf explants derived from in vitro seedlings of two sweet orange (Citrus sinensis (L.) Osbeck) cultivars, Bingtangcheng and Valencia. Effects of several factors, including culture medium, lighting condition, explant age and genotype on regeneration response were examined based on three parameters, percentage of explants producing shoots, mean number of shoots per explant and shoot forming capacity. Culture of the explants on shoot-inducing media (SIM) composed of MT salts supplemented with different growth regulators gave rise to disparate shoot regeneration, in which SIM₁ (MT + 0.5 mg L⁻¹ BA + 0.5 mg L⁻¹ Kinetin + 0.1 mg L⁻¹ NAA + 3% sucrose + 0.8% agar, pH 5.8) was shown to be the most effective medium for direct induction of shoots from leaf explants. Highly significant difference in the response of shoot bud regeneration was noted between the two cultivars, with Bingtangcheng being more responsive than Valencia. Culture of explants from fully developed leaves led to better shoot regeneration capacity in comparison to undeveloped ones. However, the two lighting conditions used herein did not cause significant difference in shoot regeneration. Phenotypic observation and randomly amplified polymorphic DNA (RAPD) analysis confirmed that all the regenerated plants from both genotypes were genetically identical to their donor plants, suggesting absence of detectable genetic variation in the regenerated plants. The data presented here demonstrated that direct initiation of plants from leaf explants has been successfully accomplished. To our knowledge, this is the first report on direct regeneration of shoots from leaf explants in Citrus, which will provide an alternative source for citrus genetic manipulation in the future.     

The potential of glauconitic sandstone as a potassium fertilizer for olive plants

This study evaluated the potential of glauconitic sandstone as a fertilizer for supplying potassium to plants. The glauconite sandstone (Maraveh, Iran), as analyzed by X-ray fluorescence, was composed of 2.24% potassium oxide plus high contents of silicon, aluminum and ferric oxide. One-year old olive trees, Olea europaea L., were grown in sand or hydroponic culture in a greenhouse under three potassium treatments. Modified Hoagland nutrient solutions based on potassium treatments including 0.5 mM K⁺, 5 mM K⁺ and 400 g glauconitic sandstone powders (per 10 L in hydroponics and per 2.5 L in sand instead of K⁺ supply) were used in both cultures. Plants grown under the three different potassium treatments did not show any potassium deficiency symptoms. In the sand culture, growth and potassium content were higher in plants fed with 5 mM potassium than with the other two potassium treatments. Growth retardation and decreased potassium content in plants fed with 0.5 mM potassium were more severe in the hydroponic culture than in the sand culture. However, plants fed with 400 g glauconitic sandstone showed higher growth in the hydroponic culture than the sand culture. Thus, glauconitic sandstone has the ability to release potassium and can be utilized in combination with other potassium fertilizers.     

Silicon nutrition of rice is affected by soil pH,weathering and silicon fertilisation

Silicon (Si) is a beneficial element for tropical grasses such as rice (Oryza sativa) and responses to applications of Si are common on highly weathered soils. However, the importance of pH (and hence Si speciation), weathering and fertilisation on Si uptake is still poorly understood. The responses of rice to Si fertilisation were studied in two variably weathered basalt soils (Red Ferrosol, Grey Vertosol) adjusted at different pH values (5.5–9.5) with three levels of acidulated wollastonite. Soil Si was extracted using deionised water (H₂O), 0.01 M CaCl₂, or 0.5 M NH₄OAc. Significant increases in Si uptake and rice biomass were observed in the Red Ferrosol following fertilisation (p < 0.01). Greater biomass production was observed at lower pH, due to decreased Si sorption and higher solution Si concentrations. Silicon uptake by rice was greater at low pH, despite similar extractable Si concentrations; suggesting a relationship between Si speciation and uptake. In contrast, Si uptake and rice shoot dry matter in the less weathered Grey Vertosol were unaffected by Si fertilisation (p > 0.05) except at the highest rate and lowest pH (5.5). Solution Si concentrations were controlled by precipitation/polymerisation reactions in equilibrium with specific soil pH values rather than adsorption processes. Silicon speciation effects (monosilicic acid vs. silicate ions) were unable to be measured due to an induced phosphorus deficiency in both soils at pH values > 8.5. In conclusion, weathered soils are more responsive to Si fertilisation and Si uptake is increased at low pH.     

Silicon priming benefits germination,ion balance,and root structure in salt-stressed durum wheat (Triticum durum desf.)

Abstract

Effects of silicon (Si) priming at 0, 0.5, 1.0, and 1.5?mM on germination, ion balance, and root structure of two durum wheat cultivars at 0, 100, and 200?mM sodium chloride (NaCl) was conducted in a laboratory. An aliquot of 200?mM NaCl with 1.5?mM Si improved Behrang cultivar germination from 54 to 88%, but in Yavaros only from 49 to 85%. In Behrang, the control root length at 200?mM NaCl increased from 5.07 to 7.11?mm when treated with 1.5?mM Si, but Yavaros only increased from 3.18 to 4.09?mm. Behrang accumulated less sodium (Na⁺) and more potassium (K⁺). For mean diameter of central and peripheral metaxylem cells, Behrang benefitted more from Si amelioration than Yavaros. Salinity affected the diameter of central and peripheral metaxylem cells to a greater degree compared to vessel number. Si soil application (1.0 and 1.5?mM Si) may help to establish durum wheat seeds grown under saline conditions.