DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu
| ŠUMARSKI LIST 1-2/1966 str. 174 <-- 174 --> PDF |
study. The seed of Larix decidua was treated with 0.05—0.4´°/o solution of colchicine during 6 to 48 hours. The produced plants are being studied. Treated were also the growing points of Salix alba with 0.05—0.3 solution of colchicine for 6 to 9 hours. Further study of the treated plants is under way. Since 1962 have been made at the Poplar Institute, Novi Sad, attempts to produce autotetraploid Poplars by sprinkling the growing points with colchicine. In 1962 were treated plants of European — American Poplars I—212 and I—154, and in 1963 40 different species and hybrids of the sections Aegeiros, Leuce and Tacamahaca. The symptoms of polyploidy (morphological changes on the leaf) have been established in 36 individuals. Under way is a cytological study of these plants. At the Institute of Forestry and Timber Industry, Ljubljana, the experiments- began in 1956, in the first place in connection with the general plan of Beech research work. Treated were with 0.05—O.P/o doses 15 different Beech provenances, and in addition 20 progenies of the individually specified phenotypes. The treatment comprised germinated and dormant seed. Cytological investigations are still in progress. V. CONCLUSION Forest areas represent a large part of the territory of Yugoslavia, and therefore it is of great significance for the economy of this country that the production on these areas be improved both by volume and quality. A definite contribution to this is also expected from the application in silviculture of the achievements of forest genetics and selection. After Worls War II material and staff facilities were created, and thus the works in this special branch of forestry began to develop in an organized and coordinated manner after 1959. In the work done so far a certain priority was given to coniferous species, Poplars and Willows. Justification for this lies first in that Yugoslavia lacks in coniferous wood, and second, that there exist very favourable conditions for the cultivation of Poplars and Willows, and, in addition, the results in the selection and improvement of the latter two species may be rapid. Applied were the well-known methods of selection, controlled crossing and artificial induction of hereditary changes. Tested was the technique of vegetative propagation, established were several living archives and seed plantations, and the experimental material for further work was produced. In this report is given information about the character of investigations, and about institutions which are carrying them out, and a list of papers in which are published details and results of previous works. On the basis of the executed works, acquired experiences, and the objectives for the renovation of forests of this country, the future works in the domain of forest genetics and tree improvement should aim at: — revision of the selected plus trees, establishment of a uniform register for them, verification of their genecit characters through progeny tests and finding out of possibilities for the preservation of the gene pool in natural forests; — study of lower taxonomic units of forest trees from the aspect of their economic significance; — deepening of the problem of intraspecific and interspecific crossing of broad- leaved and coniferous species with the objective of mass production of hybrid material for the establishment of intensive cultures; — laboratory works, which should make possible to solve the problems connected with the specific conditions in this country for the growth and development of forest-tree species. The past period of time has in the main the character of setting up a basis for further genetic and selection research, mastering the working methods, provision of laboratory and technical equipment, as well as the formation of staffs for planned investigations. In the next period the works will be concentrated on the direct improvement of forest-tree species and building-up of cultivated types of forest trees, which should have a greater economic significance. 172 |