The developmental anatomy of root buds and root sprouts was examined in the clonal tree Sassafras albidum. Root samples from 13 clones that varied widely in age and vigor were sectioned and two types of buds were found, "additional" buds and "reparative" buds. Additional buds form during the early growth of uninjured roots and they perennate by growing outwards in concert with the vascular cambium such that bud traces are produced in the secondary xylem. Reparative buds form de novo in response to senescence, injuries, or other types of disturbance. Reparative buds were found on the roots of seven of the clones, whereas additional buds were found on the roots of all 13 clones. The reparative buds had originated in the proliferated pericycle, where they were subtended by sphaeroblasts, or spherical nodules of wood. Few of the reparative buds were vascularized and none were connected with the vasculature of their parent roots. In contrast, most of the additional buds were vascularized, and the leaf traces of several of the additional buds appeared to be contiguous with the conducting xylem of their parent roots. To determine whether both bud types were functional, 82 field-collected root sprouts and 44 incubation-induced sprouts were sectioned at the root-sprout junction and examined for evidence relating to their mode of origin. None of the sprouts were subtended by sphaeroblasts, but 98% were subtended by bud traces, which indicated that they had originated from additional buds. Although reparative buds were more common than additional buds on some of the root samples, they appear to be dysfunctional at sprouting. Additional buds, on the other hand, are able to sprout both as a normal part of clonal spread and from root cuttings.

The growth of black walnut shoot cultures was compared on media differing in nutrient formulation (MS, DKW, WPM, and 1/2X DKW), cytokinin type (ZEA, BA, and TDZ), and cytokinin concentration. On WPM and 1/2X DKW media, hyperhydricity was observed at frequencies of 60-100% compared with frequencies of 10-40% on the high-salt media (DKW and MS). All three cytokinins facilitated shoot regeneration from nodal cuttings, but recurrent elongation was only observed for BA (5-12.5 μM) and ZEA (5-25 μM) with mean shoot heights of 70-80 mm being possible after two culture periods (6-8 wk) for the fastest elongating lines. ZEA was effective across all six shoot lines with mean shoot heights of at least 35 mm over two culture periods, but two of the shoot lines were 'nonresponsive' to BA with mean shoot heights of <15 mm. In contrast, when shoot tip explants were used for culture multiplication, ZEA was the least effective cytokinin with proliferation frequencies of only 30-40%. The proliferation frequencies were twice as great (75-87%) for TDZ (0.05-0.1 μM), but most of the shoots regenerated were swollen or fasciated in morphology. High rates of proliferation (61-88%) were also possible using BA (12.5-25 μM), but axillary shoots did not elongate well, growing to heights of only 5-10 mm, on average, after 4-5 wk. Since the cytokinin types and concentrations required for high-frequency (>50%) axillary proliferation had adverse effects on the morphology and growth potential of the shoots, multiplication strategies based on the use of nodal cuttings are recommended.

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ABSTRACT:The paper evaluates the quality of revitalization treatments (fertilization and liming) carried out in selected areas within Forests of the Slovakia (state enterprise) during the year 2008. Revitalization treatments were carried out in declining Norway spruce forest stands in different site conditions. Full-scale aerial technology (helicopter and crop duster) was applied. The aim of the study was to find out the total amount and its variability of both fertilizers and dolomitic limestone after their application. The analyses revealed significant differences between the amount of fertilizer and dolomitic limestone which was applied to selected areas and the required amount (norm). As for fertilization, the largest difference was found in magnesium (Mg) on Šaling area (the amount of magnesium reached only 7% ± 0.5 of the norm) and in zinc (Zn) on Ľadová area (only 8% ± 1 of the norm). The required amount according to the norm was approximately met in boron (B) on Ľadová area (65% ± 10 of the norm). Yet, a significantly lower amount of fertilizers than the required one was revealed on all selected areas. After the application of dolomitic limestone to Liptovská Teplička area the significantly lower amount than the required one was found out (72% ± 12 of the norm). On the other hand, the significantly higher amount of dolomitic limestone than the required one was determined on Smolník area (143% ± 27 of the norm). Results also show the huge spatial variability of both fertilizers and dolomitic limestone on all selected areas (from 40% up to 100% between collecting places, and up to almost 170% between collectors within the collecting places). Such high variability of applied fertilizers and dolomitic limestone and the lower total amount than the required one will influence the effect of revitalization treatments.

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