DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 1-2/1966 str. 137 <-- 137 --> PDF |
Data concerning heights of the interspecific hybrids (from 1964) and seedlings of White Willow from the mentioned populations are presented in Table 2.* Ser. Species Population No. of Heights No. data cm »t« — value 1 Salix alba L. Bakovci 122 202,21 1:2 = 11,6047*** 2 Salix alba L. Osman Polje 434 128,13 1:3 = 0,8514 3 Salix frag. L. x 9 186,22 3:2 = 3,2249** Salix alba L. In Table 2 is visible that the representatives of the population »Bakovcihave greater heights than the representatives from the population »Osman Polje«, and that they differ significantly at a level of 0,1%. Between the hybrids and the population »Bakovci« there is no significant, difference, while if compared with the population »Osman Polje« they are superior and differ significantly at a level of 1%. Between the population »Bakovci« and that of »Osman Polje« there exist not only differences in the intensity of height and diameter growth but also differences in the branch angle, colour of shoots and the time of flushing and seed setting. The arithmetic mean of the branch angle is greater in oneyear- old seedlings from the population »Bakovci« than of one-year-old seedlings from the population »Osman Polje«. As to this characteristic a significant difference at a level of 1% in the lower 1/3 of the seedling height exists. The colour of shoots in seedlings from the population »Osman Polje« does not show a greater variability and it is light-red in all representatives of the population, while in the population »Bakovci« it ranges from yellow, light-green, dark-green, light-red to chocolate brown. As regards the flushing and seed setting it was found that the individual representatives from the population »Bakovci« approach the interspecific hybrids Salix alba L. x Salix fragilis L. According to J. Wright (5) in the centre of occurence of two species of the same genus between which a hybridisation is feasible there comes to s migration of the genes from one species to another. Because on the locality »Bakovci« there exists the possibility of the intergradation between the species Salix alba L. and Salix fragilis L. It can be assumed that in this case we are also concerned with introgression, i.e. that the representatives of these populations contain also the genes of Salix fragilis L. The population »Osman Polje« is small and relatively isolated and perhaps here we also have the effects of inbreeding which brought this population to a greater homozygosity. On the basis of what precedes it would seem that the representatives of the population of White Willow posses a greater vitality and a more beautiful habit on those locations where within the population of White Willow is interspersed also Crack Willow, i.e. that probably also in these cases we are concerned with introgression. Further, we assume that the interspecific hybrids between these two species are more vital and of a more beautiful habit than the pure species. Works in this direction are in progress. * Measurements were taken in the second half of August 1965, i.e. in the middle of the second growing period. |