Suchergebnisse

International audience ; SUMMARY. The inwortance of tree-breeding research programs in Danmarkand Sweden during the last twenty years justify the trip performedin these countries ivith the following purpose: study of recentadvances of tree breeding methods, with particular attention drawnto the details of the technics concerning grafting, hybridization andestablishment of progeny tests and seed plantations.The tree breeding work is focused, in Danmark, on Beech andexotic species (Larch, Douglas fir) and in Sweden, on Scot Pine,Norway Spruce and Aspen.An accurate selection of parent individuals, followed by intra--specific hybridization in seed plantations, takes the first place inthe breeding programs. Several thousands of plus trees were selectedand multiplicated by graft. While the greenhouse technics givehighly successful grafts, important studies lead to good outdoorgrafting- technics during the recent years. The first seed orchardsfront an important program are planted in these years.If ybrid Larch and hybrid Aspen are bred by interspecific hybridization; they are used already in reforestation practice.Induced polyploidy or spontaneous polyploids used as mothertrees open new ways for investigations,• and hope for valuable improvements,especially with broadleaved trees.These both breeding technics — interspecific hybridization andpolyploidy --- are dealt with selected plus trees as mother trees.Progeny tests established and judged with the help of statisticalanalysis, take more and more place in the breeding work.in the both countries, governments, forests owners associations,timber and pulp industries, give their financial support to foresttree breeding research. The people interested in forest activitiespay the greatest attention to the advancement of the research programs.

SUMMARY. The inwortance of tree-breeding research programs in Danmarkand Sweden during the last twenty years justify the trip performedin these countries ivith the following purpose: study of recentadvances of tree breeding methods, with particular attention drawnto the details of the technics concerning grafting, hybridization andestablishment of progeny tests and seed plantations.The tree breeding work is focused, in Danmark, on Beech andexotic species (Larch, Douglas fir) and in Sweden, on Scot Pine,Norway Spruce and Aspen.An accurate selection of parent individuals, followed by intra--specific hybridization in seed plantations, takes the first place inthe breeding programs. Several thousands of plus trees were selectedand multiplicated by graft. While the greenhouse technics givehighly successful grafts, important studies lead to good outdoorgrafting- technics during the recent years. The first seed orchardsfront an important program are planted in these years.If ybrid Larch and hybrid Aspen are bred by interspecific hybridization; they are used already in reforestation practice.Induced polyploidy or spontaneous polyploids used as mothertrees open new ways for investigations,• and hope for valuable improvements,especially with broadleaved trees.These both breeding technics — interspecific hybridization andpolyploidy --- are dealt with selected plus trees as mother trees.Progeny tests established and judged with the help of statisticalanalysis, take more and more place in the breeding work.in the both countries, governments, forests owners associations,timber and pulp industries, give their financial support to foresttree breeding research. The people interested in forest activitiespay the greatest attention to the advancement of the research programs.

International audience ; SUMMARY. The inwortance of tree-breeding research programs in Danmarkand Sweden during the last twenty years justify the trip performedin these countries ivith the following purpose: study of recentadvances of tree breeding methods, with particular attention drawnto the details of the technics concerning grafting, hybridization andestablishment of progeny tests and seed plantations.The tree breeding work is focused, in Danmark, on Beech andexotic species (Larch, Douglas fir) and in Sweden, on Scot Pine,Norway Spruce and Aspen.An accurate selection of parent individuals, followed by intra--specific hybridization in seed plantations, takes the first place inthe breeding programs. Several thousands of plus trees were selectedand multiplicated by graft. While the greenhouse technics givehighly successful grafts, important studies lead to good outdoorgrafting- technics during the recent years. The first seed orchardsfront an important program are planted in these years.If ybrid Larch and hybrid Aspen are bred by interspecific hybridization; they are used already in reforestation practice.Induced polyploidy or spontaneous polyploids used as mothertrees open new ways for investigations,• and hope for valuable improvements,especially with broadleaved trees.These both breeding technics — interspecific hybridization andpolyploidy --- are dealt with selected plus trees as mother trees.Progeny tests established and judged with the help of statisticalanalysis, take more and more place in the breeding work.in the both countries, governments, forests owners associations,timber and pulp industries, give their financial support to foresttree breeding research. The people interested in forest activitiespay the greatest attention to the advancement of the research programs.