Addendum 70 T R E E I M P R O V E M E N T P R O G R A M Female buds July 18, <strong>2006</strong> P R O J E C T R E P O R T 2 0 0 6 / 2 0 0 7 Long shoot bud meristem August 31, <strong>2006</strong> Female bud August 16, <strong>2006</strong>
.2.17 Development of Yellow-Cedar Stock Plant Nutr t on Gu del nes to Enhance Operat onal Root ng of El te Clones (SPU 111 ) Robert van den Dr essche Yellow-cedar reforestation in BC is almost entirely through clonal forestry using rooted cuttings. For example, the Ministry of Forests and Range Cowichan Lake Research Station grows stock plants chosen from selected yellowcedar. These yellow-cedar plants have been selected because they have shown superior growth in the forest and also good ability to root from cuttings. The stock plants are grown outdoors, either in pots or field-planted, and are kept small by pruning because pruning, or “hedging,” tends to slow the aging process. Slowing aging and maintaining juvenility is important for producing cuttings that grow like seedlings. That is, they root easily and have vigorous shoot growth. Research studies at CLRS have shown that serial propagation by using a proportion of each generation of rooted cuttings as hedges for the next generation conserves juvenility for about 15 years. Recent operational experience indicates the potential benefit of growing stock plants in greenhouses for increasing the rooting of cuttings. This benefit may, in part, be attributed to a more optimal nutrient status for rooting ability among stock plants. Little is known about the effect of yellow-cedar stock plant nutrition on the rooting ability of cuttings, although nutrition is relatively easy to control and stock plant nutrition has been shown to influence the performance of cuttings in plants. In particular, the balance between concentrations of total non-structural carbohydrates and nitrogen has been thought important for rooting, although the relationship of cutting performance to several nutrients has been reported. Additionally, production by the WFP Saanich nursery of yellow-cedar cuttings that rooted and grew vigorously was attributed to adding fertilizer to the stock plants during the fall. Consequently, we decided to study the importance of nitrogen and phosphorus, and the time of their application, to potted stock plants of different clones and ages at the CLRS. The objective is to relate different levels of nutrient status in stock plants, achieved with the fertilizer treatments, to subsequent rooting and growth vigour of cuttings. It should then be possible to recommend levels T R E E I M P R O V E M E N T P R O G R A M P R O J E C T R E P O R T 2 0 0 6 / 2 0 0 7 of stock plant nutrient status for the successful production of cuttings. So far, a small-scale experiment has produced cuttings that have been struck this winter, and samples of these cuttings are undergoing chemical analysis. Also plant material has been potted and prepared for a larger experiment that will be conducted during <strong>2007</strong> and 2008. .2.1 Fert l ty Var at on n a Douglasfir Seed Orchard as Determ ned by DNA F ngerpr nt ng: an Update Ben La , Annette Van N ejenhu s, and Yousry A. El-Kassaby Because seed orchards represent the main sources of genetically improved seed for most artificially regenerated forests, they play an important interface role between tree breeding and silvicultural activities. The production of seed crops with high genetic quality (gain and diversity) in all BC orchards is critical to the success of tree improvement programs and to meeting the genetic quality required under the Chief Forester’s Standards for Seed (2005). This project is part of a larger initiative started by the BC Ministry of Forests and Range, the forest industry, and academia aimed at obtaining accurate estimates of the genetic quality of seedlots. Genetic quality is defined as the level of genetic gain combined with the degree of genetic diversity. Orchard managers routinely assess these estimates, and estimates such as genetic worth (GW) and effective population size (N e ) are an integral part of the evaluation of seed-orchard crops. DNA fingerprinting technology coupled with methods of pedigree reconstruction will be used to obtain accurate estimates of the genetic contribution to a specific seedlot of each parent in Western Forest Products’ Douglas-fir seed orchard. These estimates will be compared with survey assessment methods that are based on visual inspection of trees’ reproductive output. Additionally, the use of DNA technology will permit the estimation of pollen contamination from outside sources and the effectiveness of orchard management practices such as supplemental mass pollination (SMP) and over-head cooling (bloom delay). 71
Change language