Time filter

Source Type

Qiryat Shemona, Israel

Fogelman E.,Israel Agricultural Research Organization | Stern R.A.,Galilee Technology Center | Stern R.A.,Galilee College | Ginzberg I.,Israel Agricultural Research Organization
Protoplasma | Year: 2015

A mixture of 6-benzyladenine (BA) and gibberellins GA4 plus GA7 applied to “Pink Lady” apple at early phenological stages was previously shown to result in an immediate increase in epidermal cell density and associated reduction in calyx-end cracking disorder in the mature fruit, implying a long-term effect of the BA+GA4+7 mixture. Here, we analyzed the anatomical changes in the mature peel at the calyx end 210 days after full bloom (DAFB), following application of the plant growth regulators (PGRs) at the cell-division phase of fruit development, 21-50 DAFB. Experiments were conducted in northern Israel, and the PGRs were applied as the commercial formulation Superlon™ (Fine Agrochemicals Ltd.), composed of 19 g l-1 BA and 19 g l-1 GA4+7. Trees were sprayed with 0.025, 0.1, or 0.2% (v/v) Superlon™. The most obvious phenomenon was the presence of epidermal cell clusters within the cuticular matrix that were detached from the native epidermal layer located at the bottom of the cuticle and which could not be detected in the untreated control fruits. Treatment with 20 mg l-1 BA+GA4+7 (0.1% Superlon™) resulted in a markedly thicker cuticle, a higher percentage of detached epidermal cells within the cuticular membrane and a significant reduction in calyx-end cracking at harvest. The presence of cuticleembedded epidermal cell clusters may have contributed to strengthening the peel by adding more cell-wall components, thickening the cuticle layer and possibly enhancing crack repair. © Springer-Verlag Wien 2014.

Migal M.G.,Galilee Technology Center
Journal of Environmental Biology | Year: 2011

The impact of cladocerans metabolic activities on the carbon (C), nitrogen (N) and phosphorus (P) dynamics in Lake Kinneret (Israel) is presented. The study, is based on the incorporation of field data and experimental measurements. Grazing, respiration and production rates of Diaphanosoma spp., Ceriodaphnia spp. and Bosmina spp. were experimentally measured at three temperatures, and the results were extrapolated to the field biomass distribution at these respective temperatures, and the total lake capacity was calculated using the following equation: consumption = respiration + production + excretion. The field capacity of consumption, respiration and production were found to be mostly correlated with biomass density, but the temporal fluctuation of the percent of excretion from consumed energy differed. The increase in P, decline in N and decrease in the TN/TP mass ratio in the epilimnion of Lake Kinneret during 1969-2004 created N limitation. An increase in C and decline in TN, with a consequential increase in the C/TN ratio were documented. TP was augmented but the C/TP ratio was only slightly increased. During 1975-2004, P was probably, a minor limitation for cladoceran growth. The positive impact of recycled P by cladocerans under the N limitation in Lake Kinneret is discussed. There is a current threat on the water quality, derived from N limitation (mostly in summer-fall) and consequent Cyanophyta blooms. Thus, the role of recycled P by grazers may be significant. © 2011 Triveni Enterprises Vikas Nagar, Lucknow, INDIA.

Suzuki N.,University of North Texas | Koussevitzky S.,Galilee Technology Center | Mittler R.,University of North Texas | Mittler R.,Hebrew University of Jerusalem | Miller G.,Bar - Ilan University
Plant, Cell and Environment | Year: 2012

The redox state of the chloroplast and mitochondria, the two main powerhouses of photosynthesizing eukaryotes, is maintained by a delicate balance between energy production and consumption, and affected by the need to avoid increased production of reactive oxygen species (ROS). These demands are especially critical during exposure to extreme environmental conditions, such as high light (HL) intensity, heat, drought or a combination of different environmental stresses. Under these conditions, ROS and redox cues, generated in the chloroplast and mitochondria, are essential for maintaining normal energy and metabolic fluxes, optimizing different cell functions, activating acclimation responses through retrograde signalling, and controlling whole-plant systemic signalling pathways. Regulation of the multiple redox and ROS signals in plants requires a high degree of coordination and balance between signalling and metabolic pathways in different cellular compartments. In this review, we provide an update on ROS and redox signalling in the context of abiotic stress responses, while addressing their role in retrograde regulation, systemic acquired acclimation and cellular coordination in plants. © 2011 Blackwell Publishing Ltd.

Goldberg D.,Tel-Hai Academic College | Goldberg D.,Galilee Technology Center | Weissman Z.,Shenkar College
Applied Optics | Year: 2014

Optical rotation (OR) polarimeters measure only the OR of a linearly polarized wave vector caused by the optical activity of the measured material. Such polarimeters are used to detect optically active materials and measure their concentration. Here we describe a novel type of high-resolution OR polarimeter. The new polarimeter is a compact device, based on a combination of two novel mechanisms: a referencing mechanism and an optical signal-gain mechanism. The patented referencing mechanism allows accurate measurements of small ORs in the presence of considerable polarization noise. The current limit of detection of the polarimeter is ∼20 micro-degrees, which we believe can be lowered further. The polarimeter is intended to serve as an add-on detector for existing high-pressure liquid chromatography (HPLC) systems in the pharmaceutical industry. The need for such a polarimeter, its optical setup, analysis of its performance, and experimental results are hereby given and discussed. © 2014 Optical Society of America.

Henkin Z.,Newe Yaar Research Center | Seligman N.G.,Galilee Technology Center | Noy-Meir I.,Hebrew University of Jerusalem
Journal of Vegetation Science | Year: 2010

Question: What is the mechanism that underlies long-term maintenance of high herbaceous productivity after a single application of phosphorus (4.5 gP m-2 and 9 gP m-2) in a hilly Mediterranean environment in a phosphorus-deficient ecosystem? Location: Inland, 15 km E of the Mediterranean coast, W Galilee, Israel (35°15′E, 33°01′N; 500 m asl). Methods: The experiment was established in 1988. Multi-year data on above-ground biomass, botanical composition, P content of vegetation and soil, and the grazing management context of the experiment were integrated to construct a feasible account of the P dynamics of the ecosystem. Results: The productivity of the herbaceous component already responded to P application in the first year. The effect on the shrubby component of the ecosystem was marginal. The available (bicarbonate extractable) P in the upper soil layer peaked in the year after application of P and then declined to the original level within 7 years. Despite the decline in available soil P, a high, fluctuating level of herbaceous biomass production was maintained for 20 years. Legume species (Fabaceae) became a prominent constituent of the herbaceous vegetation after the P pulse. Conclusions: The long-term shift in productivity of the herbaceous component of the grazed ecosystem was triggered by a nutritional pulse that induced a feedback loop based on changes in botanical composition of the herbaceous vegetation, the animal-vegetation interaction, grazing and supplementary feeding regimen of the cattle. © 2010 International Association for Vegetation Science.

Discover hidden collaborations