Effect of seeding date, environment, and storage on canola seed vigour

Non-Peer ReviewedSeed vigour has been identified as one of the leading factors limiting stand establishment and yield in western Canada. Field studies at Scott, SK demonstrated that seed derived from Fall and April-sown canola produced higher plant densities, higher biomass at bolting, and higher seed yield than seed derived from May-sown canola. This study established the impact of seeding date on seed quality and vigour, which in turn affected emergence, seedling vigour and yield. Also, seed vigour slowly declines within one year, primarily from seed derived from the May-sown canola. Currently we are in the process of uncovering which genes and proteins are in common with vigour irrespective of seed source. We will combine our analysis with synchrotron technologies for a much more in-depth understanding of what constitutes “seed vigour” to develop a rapid, simple, and inexpensive method that will identify intrinsic characteristics of superior seed lots, as well as seed lots that lose vigour when stored under adverse conditions. In addition, we have initiated a study to compare hormones and metabolites during cold acclimation and freeze-induced injury/recovery to correlate these changes with winter survival. This research will identify traits that can be used in marker-assisted/molecular breeding programs for winter hardiness and possible genetic engineering studies on abiotic stress tolerance of seeds and plants. To further understand the processes involved in stress tolerance, we utilized gene transfer techniques to produce a PNT canola that over-expresses a novel gene which results in higher yields under stressful conditions. These PNT lines were tested in the field over 3 years across Western Canada in non-stressed, moderately stressed, or severely stressed areas. At each location, several lines flowered and matured 1 to 3 weeks earlier. The faster maturating PNT lines (up to 55% more mature at harvest) had increased yields (up to 32% increase) and enhanced seed quality (up to 87% increase in larger and more mature seed) versus the control. These results, both in controlled laboratory tests and in field trials, have been optimistic for genetic engineering of plants for enhanced stress tolerance without losing agronomical important characteristics

Observations of the galvanostatic dissolution of pure magnesium

The dissolution of pure magnesium in 0.1M NaCl under galvanostatic polarisation is reconciled in real time via video imaging of specially designed working electrodes that permit geometrically uniform dissolution. The dissolution stoichiometry was observed to be centred about n=2, however this varies according to the magnitude of the applied current. Applied currents densities 1mA/cm 2 display n 2, the latter related to a significant increase in electrolyte pH during testing

Effect of seeding date on canola seed quality

Non-Peer ReviewedCanola (Brassica napus), a cool season crop, is very sensitive to heat particularly at the flowering stage of growth. Nutall et al. (1992) reported a 3°C increase in mean maximum daily temperature (21 to 24°C) during flowering resulted in a 0.4 tonne ha-1 decrease in seed yield. Canola sown in the Fall or mid-April flowers 18 to 24 days earlier and can yield up to 30% higher than can canola sown in mid-May (Johnson et al. 1998). Canola seed weights have averaged 30% and 20% higher for Fall and early spring seed dates, respectively, as compared to the late spring seeding date. These plants flower and mature in June and thereby escape midsummer heat and drought stresses. The objectives of this study were to determine the effect of seeding date on the size, maturity, germination rate and emergence rate of canola seed

Response to comments from Shi and Atrens on the paper “Observations of the galvanostatic dissolution of pure magnesium”

A consolidated response is made here to address the comments of Shi and Atrens concerning the manuscript "Observations of the galvanostatic dissolution of pure magnesium". We provide discussion to indicate that the claims made by Shi and Atrens are invalid from an electrochemical and logical perspective, and therefore there is no basis for Shi and Atrens claim that our work provides evidence for Mg+

Silica and other materials as supports in liquid chromatography. Chromatographic tests and their importance for evaluating these supports. Part I

Reversed-phase liquid chromatography (RP-HPLC) has become a powerful and widely employed technique in the separation and analysis of a great variety of compounds with different functionalities. The most common type of stationary phase for RP-HPLC consists of nonpolar, hydrophobic organic species (e.g., octyl, octadecyl) attached by siloxane bonds to the surface of a silica support. In the first part of this article, a description of the many beneficial properties that make porous silica the most employed support in RP-HPLC will be presented, starting from the synthesis of silica. It is noteworthy that the chromatographic properties of the final column are strictly correlated to the preparation type. A silica surface possesses a number of attractive properties, but also some drawbacks. Unreacted or residual silanols interact with basic compounds and can induced peak tailing, which means a loss in chromatographic performance. This problem has lead many manufactures to produce stationary phases with reduced silanol activity which improve dramatically the peak shape of basic compounds. In the second part of this review, different approaches are proposed to obtain less reactive stationary phases