DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 9-10/1961 str. 69 <-- 69 --> PDF |
SIGNIFICANCE OF CYTOLOGIC RESEARCH IN THE PRESENT PHASE OF DEVELOPMENT OF FORESTRY GENETICS IN THIS ĆOUNTRY SUMMARY This report contains the thus far achieved results of oitological investigations in the breeding of forest tree species, i. e. in the obtaining of useful mutantš. Reviewed are the results of several authors, who, in various ways were performing the breeding of individual forest tree species. The report contains in the main studies cf polyploidy as the basis for obtaining new apecies. Reviewed are polyploidic formš — hoth natura! and antificial ones — as well as methods by which the latter are obtained. Treated is also the obtaining of autopo´lyploids by the action of various eX.ternal factcrs — some chemicals, various radiations, sudden shocks etc. — as well the obtaining of allopo^p´loids by the interspecific crossings within a genus. Presented is in detail the obtaining of the triploid European Aspen (Populus tremula) i. e. first the autopolvploid — autotriploid obtained by treating the seed with colchicin and the sllotriploid obtained by crossing the Populus tremula X Populus tremuloides species. The genu,s of Alnus and Betula received a similar treatment. Mentioned is also the importance of the discovery of distant hybrids as well as their eytologlcal treatment. At the end mention is made of the first results of investigations into the effect of X-rays on the somatic cells of Norway Spruce, works that are bei´ng carried out at this Institute. The author points to the điscrepancies among the relative sizes of chromosomes. |