DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 3-4/1973 str. 61 <-- 61 --> PDF |
Summary SOME CHARACTERISTICS OF HYBRIDS BETWEEN PINUS NIGRA AND P1NUS DENSIFLORA I the paper are described the height and diameter growth, some seed characteristics and resistance to brown spot needle blight (Scirrhia acicola) of the progeny of Fi-generation (Pinus nigra X Pinus densiflora), of the progeny from backcrossing Pinus nigia X (Pinus nigra X Pinus densiflora), as well the progenies from baccrossings which were open pollinated (Pinus nigra X (Pinus nigra X Pinus densiflora) X open pollinated). On the basis of results of experiments laid out in the nursery and in the field, the authors came to the following conclusions: 1. The Fi-generation of hybrids of Pinus nigra X Pinus densiflora stands better transplanting than the pure Austrian Pine when transplants are 1+3 year-old, and it exhibits a more vigorous growth at the age of 8 years. 2. Progeny from the backcrossing of the mentioned hybrid exhibits also a vigorous growth than the Austrian pine at the age of 9 years. 3. Progeny of three hybrid families of the backcrosses exhibits a more luxuriant growth than that of Austrian Pine at the age of two years. The size of seed (length and thickness) of backcrosses is intermediate in relation to the parent species. 4. The phenomenon of a more luxuriant growth in backcrosses and in their progeny in relation to the progeny of pure Austrian Pine may be explained by means of the hypothesis of Wright et al., according to which there occurs a selection during embryogenesis, which favours hybrid embryos. 5. Hybrids between Austrian Pine and Japanese Red Pine fructify already in early youth, and in this respect they exhibit the phenonmenon of heterosis. Considering that the backcrosses and their progenies display the phenomenon of heterosis, and also that they are blooming early, and abundantly, plantations of hybrids may also be used as seed sources. 6. Backcrosses of hybrid families are more resistant to brown spot needle blight (Scirrhia acicola) than the progeny of pure Austrian Pine. 7. With respect to the mentioned conclusions, the authors are of the opinion that the introduction of the investigated hybrid into plantations, especially into those for the afforestation of degraded karst lands is promising. Therefore a further study of this hybrid ought to be carried out both from the viewpoint of growth, wood quality, resistance and comb´ning ability of parents, and the viewpoint of the interaction genotype — environment. |