Breeding in all conifers except Douglas fir has reached the end of selection and progeny-testing work in the first generation. Advanced generation breeding will concentrate on Sitka spruce in which up to six sublines may be developed for use in an assortative mating scheme to provide a base population for second generation selections.
Completion of full-sib crosses within these lines and the establishment of the ensuing field trials will be the priority of the next few years.
Selection work in the next generation could be greatly facilitated through the use of molecular markers which correlate closely with the expression of characters of economic importance. The development of such markers will follow the recent establishment of appropriate test material in field trials in which to carry out such studies.
Tissue culture techniques
Tissue culture techniques, which could form the basis of producing truly clonal material in which gains could be increased beyond current levels, is hampered by maturation effects. These prevent vegetative propagation of material which is old enough to have passed through field evaluation. Long term storage of embryonic or meristematic tissue would circumvent this problem and a detailed study of cryopreservation methods will take place over the next three years.
Selection of material for study
Recent increasing interest in the planting of local material of native species has been supported by the development of a map of local seed zones.
However, there is scant evidence of the level of adaptive variation which exists among populations of native species in Britain. New field trials of material from representative populations will be established across a range of sites for the study of adaptive characters. Selection of material for study will depend on the completion of some initial inventory surveys to define the distribution and availability of appropriate populations.