英国西加云杉和落叶松的无性繁殖

本文概述了英国西加云杉和落叶松无性繁殖的历史、研究背景、生产方法、扦插苗的造林表现和大规模应用的发展前景。目前已优化无性繁殖系统的扦插苗生产成本为常规的１／３，且扦插苗不增加造林成本。

Vegetative Propagation of Picea sitchensis and Hybrid Larch (Larix × eurolepis Henry) in the UK

Currently the amount of forest coverage in Britain is very low compared to other European countries.Only just 10% of the land area is under forest,The tendency in Britain has been to clear native forest for agricultural purposes nearly all British commercial forests are plantations(man made).About 1.1 million hectares are commercial forests,similar quantity is under private ownership,making 2.2 million ha in total.Sitka spruse { Picea sitchensis (Bong.) Carr.} is the predominant tree species comprising approximately 50% of the current total planting.Larch stocks are produced annually in British forest nurseries amounting for 7 percent of total nursery cuttings production.Japanese larch { larix kaempferi (Lambert) Carr.},hybrid larch (Larix × eurolepis Henry),and European Larch (Larix decidua Miller) respectively account for 48%,35% and 17% of this figure.F₁ hybrid larch is preferred over European larch and Japanese larch for its superior vigour,form and disease resistence.The history of the development of large scale vegetative propagation,research in cutting production systems,growth performance of cuttings,and future development of coniferious species in UK is described briefly.Production systems developed by the Forestry Authority Research Division have been modified by growers to reduce the cost of trees produced by cuttings to twice the cost of conventionally produced material.Forestry experiments have further demonstrated that no additional establishment costs are associated with cuttings.It has been brought about a great advance in clonal forestry that studies on coniferious species genetic improvement and vegetative propagation.