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