SIGNIFICANCE OF THE ABSENCE OF SEED DORMANCY IN WHITE BARK PINE GENE POOL CONSERVATION

The absence of seed dormancy, i.e. the development of seedlings from embryos without dormancy, occurs most frequently in the Paleotropic, Neotropic and Australian floristic regions. In woody plants of the temperate region, this character is most often latent and occurs in unfavourable environmental conditions. The absence of seed dormancy or vivipary is an adaptive strategy that enables the generative or vegetative reproduction of adult trees in the extreme or specific conditions of vegetation in which the rooting period is short due to the moisture regime. A group of 12 trees of white bark pine were analysed 60 years ago, a group of 8 trees 35 years ago, 5 trees 50 years ago, and 2 trees at present (2012) in the park of the Old Meteorological Observatory in Belgrade using the methods of comparative morphological and genetic-physiological analyses of seed and needle samples. The absence of seed dormancy was confirmed in the continuity of 60 years. Studies of this type have both theoretical and practical significance to the process of white bark pine breeding, as well as to the production of planting stock intended for the very steep and dry southward slopes of the Mediterranean and sub-Mediterranean mountains in Serbia, Montenegro, Herzegovina and Macedonia.