Elvira Martínez

Germination of broccoli seeds exposed to UV-C radiation (priming) for a 30-minute period and tolerance to water stress was evaluated. These findings suggest that the adverse effect of drought on the germination rate can be circumvented by seeds primed with a UV-C radiation at a wavelength of 254 nm during 30 min.

Nanotechnology is rapidly advancing towards the development of applications for sustainable plant growth and photosynthesis optimization. The nanomaterial/plant interaction has been intensively investigated; however, there is still a gap in knowledge regarding their effect on crop seed development and photosynthetic performance. In the present work, we apply a priming procedure with 10 and 50 mg/L Pluronic-P85-grafted single-walled carbon nanotubes (P85-SWCNT) on garden pea seeds and examine the germination, development, and photosynthetic activity of young seedlings grown on soil substrate. The applied treatments result in a distorted topology of the seed surface and suppressed (by 10–19%) shoot emergence. No priming-induced alterations in the structural and functional features of the photosynthetic apparatus in 14-day-old plants are found. However, photosynthetic gas exchange measurements reveal reduced stomatal conductance (by up to 15%) and increased intrinsic water use efficiency (by 12–15%), as compared to hydro-primed variants, suggesting the better ability of plants to cope with drought stress—an assumption that needs further verification. Our study prompts further research on the stomatal behavior and dark reactions of photosynthesis in order to gain new insights into the effect of carbon nanotubes on plant performance.

Crop plant varieties exhibit diverse reactions when subjected to wastewater irrigation in terms of seed germination, seedling development, and overall productivity. Magneto-priming, which involves treating seeds with an appropriate magnetic field, is gaining popularity as the preferred technique due to its effectiveness and environmentally friendly characteristics for improving seed vigour, growth, and plant yield. In this study, magneto-primed and non-primed broccoli seeds were irrigated with distilled or wastewater and kept under observation for a 10-day period to record seedling growth. A laboratory study was conducted to evaluate the impact of magneto-priming on broccoli seeds with a homogeneous stationary magnetic-field strength of 5.9 mT for 1 h. They were irrigated with two types of water: distilled and wastewater. Another test was performed to evaluate the effect of 1-h and 2-h magneto-priming on seed germination when seeds were irrigated with wastewater. From the results, the broccoli seedlings irrigated with distilled water grew higher and heavier than the ones irrigated with wastewater, probably due to the significant amounts of salts in organic wastewater. Nonetheless, the saline effect of wastewater was ameliorated when seeds were previously magneto-primed. All the germination parameters of broccoli seeds irrigated with wastewater were significantly reduced when seeds were magneto-primed for both periods.

The spectroscopy technique of Micro-Raman is an appropriate method to investigate the microscopic structure of internally heterogeneous (i.e., composed of multiple layers) agro-food products. The effects of applying magnetic fields (magneto-priming technique) and imbibition on the chemical makeup of Triticale seed were studied, particularly in its pericarp, germ and endosperm parts, with the help of Micro-Raman. In light of the results obtained, the magneto-primed seeds soaked in water presented a greater number of chemical compounds than the control seeds, although those treatments were not as effective as the ones with only magneto-priming. The effects of the magneto-priming treatment were especially noticeable in the endosperm due to the large number of chemical compounds identified. The seed composition differences among treatments showed that the use of Micro-Raman jointly with magneto-priming is an appropriate method to obtain and analyse information of the key components of Triticale seeds, notably regarding their pericarp and endosperm.

Hyperspectral imaging is an appropriate method to thoroughly investigate the microscopic structure of internally heterogeneous agro-food products. By using hyperspectral technology, identifying stress symptoms associated with salinity, before a human observer, is possible, and has obvious benefits. The objective of this paper was to prove the suitability of this technique for the analysis of Triticale seeds subjected to both magneto-priming and drought and salt stress conditions, in terms of image differences obtained among treatments. It is known that, on the one hand, drought and salt stress treatments have negative effects on seeds of almost all species, and on the other hand, magneto-priming enhances seed germination parameters. Thus, this study aimed to relate hyperspectral imaging values—neither positive nor negative in themselves—to the effects mentioned above. Two main conclusions were reached: Firstly, the hyperspectral application is a feasible method for exploring the Triticale structure and for making distinctions under different drought and salt stress treatments, in line with the data variability obtained. Secondly, the lower spectral reflectance in some treatments—in the 400–1000 nm segment—is the result of a great number of chemical compounds in the seed that could be related to magneto-priming.

In the past 15 years, physics education research has shed light on the difficulties students encounter in learning physics. In response, a wide variety of new models of physics instruction have become available. In the last 4 years, we developed a physics remedial course to decrease the dropout rate of university students while promoting more efficient learning of the principles and laws of physics. To motivate students to do research on physical phenomena we focused our attention on simulations to help students learn different subjects concerning physics word. This article presents examples of simulations generated by the authors using Modellus software for interactive learning of simple harmonic motion. In addition, videotapes, tests and other didactic material are available for students in a virtual environment. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 757–761, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20266