Forest Genetics Projects

Seed Production Research - Flowering and Pollen Physiology Research

Considerable research support of all tree improvement species has focused on intensive seed orchard management, e.g., flowering (accelerated maturation and induction of amabilis and subalpine fir), pollen management (collection, storage, testing, and application of western redcedar pollen) and orchard design (crown pruned, clonal row Douglas-fir orchards). For example, accelerating crown development in potted grafted stock of amabilis and subalpine fir are used for flower induction treatments, to establish protocols for orchard management. We are also considering the effect of orchard environment (site and temperature) on the adaptive properties of interior spruce progeny. By providing clients with tested procedures for seed orchard management, we are assisting orchard managers in meeting provincial goals for the deployment of well adapted, high gain reforestation stock. The flowering physiology program has wound down with the retirement of Dr. Joe Webber, but we try and maintain critical research where we can with contracting.

Determining Barriers to Seed Production in Abies spp. (Joe Webber)

The objective of this project is to collect yearly information on the flowering intensity, pollen cloud density and cone yields for amabilis and subalpine fir. It is our long term goal to monitor annual spring flowering and fall seed yields to determine the principal barriers to securing operational quantities of high quality amabilis and subalpine fir seed. This includes estimates of annual pollen cloud density and meteorological conditions during the period of seed cone receptivity as well as incidence of insect or disease observed during the sampling periods (spring flower counts and fall cone analyses). The results of this project are focused at two target users. Field foresters, who will have a better appreciation of the periodicity between good cone crops and cone collectors, who will have better information about the biotic (pollen cloud, insects) and abiotic (frost) factors affecting early cone development and seed quality. The results of this project will aid planning for more effective regeneration in partial-cut systems and better seed quality for nursery growers.

Selection of Stands and Flower Monitoring for 1998

The same general areas used for the second year (1997) monitoring of amabilis and subalpine fir were used or the 1998 monitoring: Terrace and Campbell River for amabilis fir and Terrace and Sicamous for subalpine fir. Again pollen monitoring was completed, and will be available in a combined year end report for this project.

Two stands (plots) from each of the two general areas were selected just prior to seed- and pollen-cone bud burst. At the time of stand selection, approximately 10 trees were sub-sampled to determine flower intensity of seed cones. A categorical scale was used as follows: 1=0-10 cones per tree; 2=11-100 cones per tree; and, 3=>100 cones per tree. The date of seed cone bud burst for the stand was estimated and then revisited four weeks later to determine early cone development (primarily cone abortion). Sample branches from each of three trees per stand were collected and shipped to GRRS for assessment which included counting the number of seed cones developing normally and determining the proportion of poorly developing or aborting cones. Also an attempt was made to dissect the poorly developing cones to determine if insects were a substantial cause of aborting cones.

The final visit to the plot was in late August for cone collections and subsequent cone analyses. Where possible, 10 cones from each of 10 trees per stand were collected. At the time of cone collection, any abnormal development or insect damage was noted. All cones were shipped to GRRS where the number of cones and their volume were recorded. Cones are currently being subjected to post-harvest conditioning according to Seed Center protocol (14° C and 65% RH) for 6 weeks. Finally, all cones will be extracted, cleaned and the number of filled and damage seed (insects) determined by x-ray analyses.

Cone Analyses

The cone crop in Terrace for both amabilis and subalpine fir were rated as medium and good, respectively. The crop for subalpine fir was one of the best we have monitored over the past three years. The contractor picking the subalpine fir crop noted an important observation. All collections were made from younger stands (around 70 years old). Cones maturing on more mature (>200 years old) trees were affected by insects and suffered more abortion. This is becoming a general trend. Younger trees abort less and produce better cones at maturity.

The crop for amabilis fir was medium. Again, experience gained from 1998 suggested that over-mature trees (>200 years old) should be avoided for cone harvesting. This was the observation at both the Kleanza Lake and Skeena West sites. Cones were collected from trees around 100 years old and it was noted that insect damage on mature and over mature trees was very heavy.

Accelerated Graft Development

The two series of amabilis and subalpine fir grafts continue to be cultured to rapidly increase their crown size. The first series of amabilis grafts are now five years from grafting with an average height of about 0.75m. A limited induction was completed on this stock by withholding water misting (cooling) and allowing temperature within the poly-house to increase to ambient. Next year we will plan for more formal induction treatments (GA4/7, root-pruning, girdling and drought). We will continue to develop the crown structure on the second series of amabilis and subalpine fir grafts.

Extension

We now have three years of observation on the variation of flowering and seed production at two amabilis and subalpine fir sites. This information has been summarized in a recent article titled, "Abies seed production: towards securing future seed supply." authored by J.E. Webber and published in TICtalk volume 2, number 1, 1999, pages 8-9.

The Effect of Seed Orchard Environment on Progeny Performance of Interior Spruce (Joe Webber)

The concept that environment can have an effect on progeny performance has been demonstrated in interior spruce. Progeny created from the same seed cone parents of interior spruce growing in Prince George and Vernon differed in adaptive traits (frost hardiness) and growth characteristics (Stoehr, et al. 1998. Can. Jour. For. Res. 28:418-427). The term that is most commonly used to describe this phenomenon is seed orchard after-effects.

In order to determine the magnitude of after-effects in interior spruce, further work was done by creating single parent crosses on more seed cone parent trees and comparing both sources of pollen (i.e., north on north and south on north for PG and south on south and north on south for Vernon) using the same mating design at both locations. We then intend to compare the progeny for growth traits and frost hardiness. Performance over the last few years has been assessed and we are in the process of publishing the results. Interestingly, work from Norway suggests that DNA 'methylation' may be one of the underlying operative causes of this phenomenon. We will continue to monitor our tests over time, as well as other research to ensure our seed orchard seed does not accrue any serious long term risks by being produced in warm climates.