Comparative Growth Responses and Ionic Relations of Four Cereals during Salt Stress

Four varieties, one each of triticale, wheat, rye and barley were grown in nutrient solution without and with the addition of 75 and 150 mM NaCl. Plants were exposed to salinity for two weeks and growth and ionic relations of plants were measured. Growth of four cereals varieties was affected to different degrees with salinity and shoot fresh weight/dry weight ratios decreased with increase in salt concentration in root medium. Shoots of barley variety accumulated high content of Na and Cl which were primarily due to higher rates of net ion transport from root to shoot. Higher accumulation of Na and Cl in barley variety shoot accompanied by better relative growth rates indicated plant's ability to compartmentalize ions in vacuoles.     

A simple irrigation scheduling approach for pecans

Pecans are a major crop in New Mexico's Lower Rio Grande Valley (LRGV). It is estimated that New Mexico is responsible for about 21% of the world's pecan production (Lillywhite et al., 2007). Currently, approximately 12,000 ha of pecan orchards at various stages of growth consume 45% of the area's irrigation water. Pecan evapotranspiration (ET) varies with age, canopy cover, soil type, crop density and method of water management. Intense competition for the LRGV's limited water supply has created a serious need for better water management through improved irrigation scheduling. Annual pecan ET ranges from as low as 500 mm to as high as 1400 mm. Diversity of the pecan crop coefficient (K_c) and ET makes the task of irrigation scheduling for this crop very complicated. Using remote sensing technology and field ET measurements, a simple relationship was developed to relate crop coefficient and ET to canopy cover. This relationship is then used in combination with climate data to calculate daily and weekly water requirements for each orchard. The difference between annual ET values estimated from canopy cover and values measured with an eddy covariance flux tower ranged from 2 to 5%. The average ratio of estimated monthly ET values over measured ET values was 1.03 with the standard error of the estimate ranging from 10 to 20 mm/month. This methodology provides a simple tool that farmers can use to schedule irrigation of pecan orchards. Even though the methodology was developed for irrigation scheduling in the LRGV, it can be used in other locations by transferring the reference crop coefficients using K_c-GDD relationships.     

Effect of different pre-sowing treatments on seed germination percentage and growth performance of <Emphasis Type="Italic">Acacia auriculiformis</Emphasis>

Seed morphology, germination and seedlings growth of Acacia auriculiformis were studied. The experiment was conducted in the nursery of Forestry and Wood Technology Discipline, Khulna University, Bangladesh. Matured seeds of the species were collected from healthy trees of road side plantation from different areas of Khulna District, Bangladesh and treated with five pre-sowing treatments (control, immersion in cold water, immersion in hot water, scarification with sand paper and immersion in concentrated H₂SO₄). The average length, breadth and thickness were found to be (0.58±0.017) cm, (0.44±0.007) cm and (0.20±0.089) cm, respectively. Germination was conducted in polybags with a mixture of top soil, coconut husk, coarse sand, and fine sand in a ratio of 3:4:1:1. Results reveal that pre-sowing treatments influences the germination rates of seeds that significantly increase the percentage germination compared with those in control (43%) and cold water treatment (52%). The highest germination success rate was found 83% in hot water treatment followed by 78% in scarification with sand paper, and 75% with immersion in H₂SO₄. Germination started from 7 to 12 days and completed between 28 and 35 days period in all treatments. ANOVA showed the significant difference (p<0.05) among the treatments in seed germination, but no significant difference among treatment with regard to starting day, closing day and total germination period. In case of height and diameter growth, seedlings originated from the seeds with hot water treatment shows significantly higher in wet season (from May to July). Hot water treatment can be recommended on seed germination of the species in rural Bangladesh.     

Assessment of maize response to Minjingu phosphate rock and triple superphosphate applied under different P-application strategies in a Ferralsol in Tanzania

Phosphorus undergoes many reactions in acid soils, most of which convert it to less-available forms. There is a need to search for P source and P-application strategies that minimize the unfavourable reactions and optimize the benefits derived from P application. A field experiment was conducted in a Ferralsol for three years (2004–2006) to compare the effectiveness of Minjingu phosphate rock (MPR) with triple superphosphate (TSP) as assessed by maize response. The same experiment compared two P application strategies, i.e. P recapitalization and seasonal P application strategy, and two P rates, namely a standard P rate (SPR) and half of the SPR. The experiment followed a randomized complete block design with nine treatments replicated four times. Both P sources increased yields, nutrient P and Ca uptake significantly (p < 0.05) over the control, but the difference between sources was not significant. Both P sources increased the P concentration in ear leaf to the critical range ≥ 0.2% in all three seasons. Cumulative yields were comparable in the two P-application strategies. Both P sources had high residual effects whereby grain yield increments in the 2006 season ranged from 1 to 2 t ha^?1. Hence, MPR can substitute for TSP without yield reduction in Ferralsols. The seasonal P-application strategy was comparable with the P recapitalization, thus either can be chosen.     

Testing the Feasibility of Using the ForSAFE-VEG Model to Map the Critical Load of Nitrogen to Protect Plant Biodiversity in the Rocky Mountains Region, USA

The ForSAFE-VEG model was used to estimate atmospheric nitrogen deposition and climate effects on soil chemistry and ground vegetation in alpine and subalpine zones of the northern and central Rocky Mountains region in the USA from 1750 to 2500. Model simulations for a generalized site illustrated how the critical load of atmospheric nitrogen deposition could be estimated to protect plant biodiversity. The results appear reasonable compared with past model applications in northern Europe. Atmospheric N deposition critical loads estimated to protect plant biodiversity were 1 to 2 kg N/ha/year. This range could be greater, depending on the values selected for critical site-specific parameters (precipitation, temperature, soil chemistry, plant nutrient uptake, and any eventual harvest of biomass) and the amount of biodiversity change allowed.     

Gibberellic Acid and Boron Enhance Antioxidant Activity,Phenolic Content,and Yield Quality in Pyrus Communis L.

Gesunde Pflanzen - Foliar application of micronutrients and plant growth regulators (PGRs) is one of the strategies of plant-feeding direct through leaves to allow rapid uptake irrespective of soil...     

In vitro Labeling of Neural Stem Cells with Poly-L-Lysine Coated Super Paramagnetic Nanoparticles for Green Fluorescent Protein Transfection

Background: The magnetic nanoparticle-based transfection method is a relatively new technique for delivery of functional genes to target tissues. We aimed to evaluate the transfection efficiency of rat neural stem cell (NSC) using poly-L-lysine hydrobromide (PLL)-coated super paramagnetic iron oxide nanoparticles (SPION). Methods: The SPION was prepared and coated with PLL as transfection agent and the transfection efficiency was evaluated in rat NSC using enhanced green fluorescent protein-N1 plasmid containing GFP as a reporter gene. NSC was incubated for 24 h in cell culture media containing 25 µg/ml SPION and in different concentrations of PLL (0.25, 0.50, 0.75, 1 and 2 µg/ml). Cell viability was determined before and after transfection for every concentration using Trypan blue assay. Characterization of prepared uncoated (SPION) and coated (SPION-PLL) complexes were evaluated by a transmission electron microscope and the zeta potential. Results: PLL at 0.75 μg/ml showed optimal results with 25 μg/ml SPION concentration compared with other PLL concentrations (0.25, 0.50, 1 and 2 μg/ml). The 18% efficiency of the transfected cells showed green fluorescence. Conclusion: Transfection with SPION is an efficient, non-viral gene transfere method. Key Words: Neural Stem cells (NSC), Nanoparticles, Transfection     

Loss of Sodium from Mung Bean Shoots to Saline Root Media

In a pulse chase experiment, seedlings of mung beans were loaded with radio-active isotope (²²Na) in 50 mM NaCl solution for 4 days. Individual seedlings were transferred to non-labelled salt solution and the retranslocation of sodium was studied over a period of one week. Growth of seedlings was also studied during this period. Net loss of sodium was observed from roots and stem to the root medium. The leaves accumulated some of the retranslocated sodium as well. The rates of sodium retranslocation and other relevant data are discussed in this paper.     

Serological survey of Brucella abortus antibody prevalence in the one-humped camel (Camelus dromedarius) from eastern Sudan

A five year investigation of Brucella antibody prevalence in camel sera was conducted in 1502 one-humped camels of both sexes and different ages. The average (mean +/- SD) incidence rate of positive results was 6.95 +/- 1.55%. Among adult one-humped camels, the rate was 4.94 +/- 2.51% in males and 13.76 +/- 4.41% in females. Juvenile one-humped camel calves showed a 0% incidence rate in males and a 1.82 +/- 3.64% in females. Antibodies against Brucella abortus were prevalent in one-humped camel sera throughout the five years of the survey with incidence rates of 6.54, 5.79, 9.32, 5.03 and 8.06%, respectively from 1985 to 1989.