DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 1-2/1966 str. 135 <-- 135 --> PDF |
INTERSPECIFIC HYBRIDS BETWEEN WHITE WILLOW (Salix alba L.) AND CRACK WILLOW (Salix fragilis L.) (Contributed paper) by ANTE KRSTINIC Forestry Faculty, Zagreb, Yugoslavia. During a three-year work on the selection of White Willow, we visited a number of localities in Yugoslavia. According to A. Krstinić — M. Vidaković (1) from the genetic point of view the populations of White Willow on the surveyed localities distinguish themselves in a wide range of variability. This variability does not manifest itself only in the essential characteristics of the habit (straightness, branching), but also in the basic taxonomical characteristics (leaf, buds, colour of shoots, etc.). In the region of the Sava River the representatives of the population of White Willow have to a great percentage bent and spirally grown stems, thick branches which are relatively lowplaced on the stem, while the branch angle is small. Along the Drava River we found a population of White Willow whose representatives exhibit stems of long commercial lengths, with marked staightness, free of spiral grain, and great growing power. In these populations we also found the best specimens of plus trees. Several of these best plus trees with respect to their taxonomic characteristics could not be determined either as being typical individuals of Salix alba L. or Salix fragilis L. Thus we were led to assume that in this case we had to deal with the interspecific hybrids between these two species. After a detailed survey of a wider area along the Sava and Drava Rivers we found that along the Sava River Crack Willow (Salix fragilis L.) is very scarce and that it occurs only in clearings and at the borders of stands. In the area of the Drava River Crack Willow (Salix fragilis L.) occurs very frequently and not only that it appears in clearings and at the stand borders but is largely interspersed within the population of White Willow. In the area of the park forest of »Maksimir«, Zagreb, along the brook of »Bliznec« there occurs also Crack Willow together with White Willow, but in that locality too we found specimens of arborescent Willows which respect to the taxonomic characteristics do not represent pure species either. In order to verify our assumption that in this case we had actually to deal with interspecific hybrids of White and Crack Willow we collected during 1964/65 the seed from a number of female plus trees and raised plants, while the male plus trees were crossed with pure species of Salix alba L. and Salix fragilis L. On analysing the generative progenies we found that also in that case we were considered with interspecific hybrids of the mentioned two species because in the progeny there appear pure parent |