DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 1-2/1969 str. 61 <-- 61 --> PDF |
The question arises why is it that individuals with tortuous stems occur rarely despite the fact that the stem form is monohybridally inherited, and that, in addition, the tortuosity dominates over the stranightness? It may be assumed that the homozygotes for the stem tortuosity are incapable to survive. In order to prove this or to confirm what in this paper has abready been explained, it is necessary to preserve the raised plants, to single out the crooked-stemmed male individuals and to cros them with female individuals of the same phenotype. In so far as the mentioned character is monohybridally-dominantly inherited, while the homozygotes are incapable to survive, the splitting in the progeny will be 2 : 1 (without the homozygotes) or 3 : 1 (together with the homozygotes). Parallel with the works on the controlled hybridization, it will also be necessary to undertake cytological investigations in order to determine also the number of chromosomes in arborescent species of Willow which were the subject of our investigations. On the basis of the results obtained it may be concluded: 1. That the stem form possesses a discontinuous variability in the hybrid families of arborescent Willows so that this feature is of qualitative character. 2. Stem straightness is inherited recessively in relation to tortuosity. 3. It is safe to say that the stem form in arborescent Willows is monohybridally inherited. |