University of Alberta researchers have, for the first time, captured a much better view of what may be contributing to failures in lodgepole pine seed orchards - a tree essential to Alberta's forest industry.
The researchers used synchrotron microcomputed tomography, an advanced 3D imaging method usually used in medicine, in a pilot study to visually explore why some pollinated female pine cones, known as conelets, are healthy while others dielong before they fully develop.
Carried out at the Saskatoon-based Canadian Light Source, the technique provided a clearer view of the internal reproductive structures of healthy and unhealthy conelets - a big improvement over previous low-resolution images, says study co-author Barb Thomas, a professor in the Faculty of Agricultural, Life & Environmental Sciences.
"This represents the next step in using this technology to help determine why conelet failure occurs and how we can potentially change our management in the orchards," she notes.
The scans were completed in two parts and then carefully stitched together to create one whole, 3D image - something that hadn't been done before because the conelets were too large to capture in one shot.
Crucial to Alberta's forest industry, the lodgepole species accounts for about 50 per cent of the harvested trees in the province, grows quickly to restore disturbed sites, and feeds timber and pulp production.
The technique tested in the research created detailed images of two conelet genotypes without having to physically cut them open - another first - avoiding damage from traditional dissection that could compress or tear the tissue.
"This way, several aspects of the same conelet can be closely examined vertically and horizontally in very thin slices," notes Emelie Dykstra, a co-author on the study.
The cutting-edge imaging revealed significant differences in the interior structures of the conelets; those that were healthy had greater tissue volume and more "organized" or consistent internal space for seed development. Failed conelets were smaller and had less defined internal cavities, showing the rapid decay after pollination failure.
The findings emphasize how closely structural development of a conelet is tied to pollination, "which can better inform the forestry industry and researchers to focus efforts on increasing success in that area," Dykstra says.
The imaging method could also be used to more closely study other related processes, such as seed development after fertilization, which occurs the following spring, adds Thomas.
"In the plant science field, this is a groundbreaking technique that can offer a more complete understanding of the reproductive biology of trees."
