Interior SpruceThe Interior spruce tree breeding program in British Columbia is structured in two phases. Phase one began in the mid-1960s and focussed on three geographic regions: Prince George, Bulkley Valley, and the East Kootenays. Phase two began in the mid-1970s and focussed on other geographic regions where Interior spruce is commercially and ecologically important. The program has progressed to the point where much of the current planting stock (more than 80 million per year) comes from rogued first-generation seed orchards. Full-sib second generation progeny tests are in place for three seed planning units (SPUs). 65 trees from the 10-year-old Series I Prince George Selection Unit second generation progeny tests have been selected, grafted and established in seed orchards (Fig 1).
In the mid-1990s interior seed planning zone review, the Prince George Interior spruce SPU was expanded to include six small seed planning units from the Phase II program and the Prince George Selection Unit from the Phase I program. This merger resulted in a composite breeding population for the Prince George SPU that included 1140 tested parent trees. The second generation crossing plan for this new zone consisted of crossing the top 144 parents in a 6-tree incomplete partial diallel crossing plan where each parent was crossed with four other parents. This plan resulted in 24 partial diallel units and a maximum of 288 crosses. Crossing was completed over four breeding seasons and progeny tests were planted on four sites in spring 2006. These tests were established in an incomplete block alpha design with ten replicate blocks per site, 13 blocks per replication and 20 seedlots per block. Experimental units consisted of three-tree row plots with trees planted at 2 x 2 m spacing (Fig 2). In spring 2006, four realized gain tests were established in the Prince George SPU. These tests will compare the growth performance on an area basis of elite families, seed orchard seedlots, and a wild stand bulk seedlot comprised of a composite of ten wild stand seedlots. Controlled crossing to produce full-sib families for second generation selection is ongoing in the Nelson SPU. Western LarchCommercial planting of western larch continues to increase in BC with 6 to 7 million seedlings planted annually over the past five years (Fig 3). Sixty-eight percent (4.5 million) of these seedlings originated from seed orchards located in Vernon. Second generation crossing in the East Kootenay and Nelson SPUs is nearly complete. In spring 2006, grafting was completed for the establishment of a new high elevation seed orchard for high elevation sites in the Nelson SPU. Realized gain genetic tests were established in the East Kootenay and Nelson Low SPU in 2005 and 2006, respectively. Maintenance of the subalpine larch (Larix lyallii) gene archive plantation in Vernon is ongoing (Figs 4 and 5). Interior Douglas-firSecond generation controlled crossing continued in the Nelson low elevation SPU and is near completion. In 2006, four 15-year-old open-pollinated progeny tests in the East Kootenay SPU were maintained and measured, and two 20-year-old sites in the Nelson SPU were measured. Various supporting research plantations were maintained and measured. These included the 20-year-old seedling/steckling study and five Submaritime Douglas-fir adaptation plantings. The pilot interior Douglas-fir Armillaria genetic resistance study was completed and data analysis is in progress. This test included 1,566 trees from 88 open-pollinated families and four SPUs. The artificial inoculation technique proved very effective as inoculum was present in 1408 of the 1566 treated trees (Fig 6). After three years, 83% of the trees had been killed by Armillaria and 6% of the living trees were completely girdled and near death (Fig 7). Family mortality was 44-100%. In general, families from warmer and drier environments were more tolerant than trees from colder and wetter environments. Thirty-year height and diameter measurements were completed in the Trinity Valley range-wide interior Douglas-fir provenance test. After 30 years, provenances originating from the east slopes of the U.S. Cascade Mountains and the B.C. Coast Mountains (Coast-Interior Transition, CIT zone) continue to demonstrate superior growth (Fig 8). Compared to provenances from the B.C. Interior Cedar-Hemlock (ICH) zone, the CIT provenances were 10% taller, 13% larger in diameter, and 33% larger in volume. Provenances from the southern U.S. are failing (Fig 9) and provenances from the interior dry belt typically demonstrate slow growth and high levels of Rhabdocline needle disease (Fig 10). In spring 2005, forward selections were made within the best Coast-Interior Transition zone provenances for inclusion in advanced generation breeding (Fig 11).
Ministry Contact: Alvin Yanchuk |
 |
| |||||||||||||||||
