engleski

Nuclei distribution pattern in the tissue of vegetative buds of spruce species (Picea abies, Picea pungens and Picea omorika) grown in vivo and in vitro

The nuclei distribution pattern, the mitotic activity and dimension in the vegetative buds of three spruce species: Picea abies, P.pungens and P.omorika, grown in vivo and buds of P.abies grown in vitro were investigated for better understanding the physiological status of donor plant on which depends the successful tissue culture. The mitotic index, the position of mitotic spindles in the embryonic shoots of Picea abies, P.pungens and P.omorika during the transition from winter to spring were determined as well as the same parameters in the vegetative buds of P.abies grown in vitro. The induction of P.abies adventitious buds was achieved by BA-pulse and cultivation on MCM media. Longitudinal sections of buds, 3um thin, derived from in vivo and in vitro were stained with Toluidine blue O, Hoechst 33342, 33258 and DAPI. Cells with big, round nuclei were present in embryonic shoot in winter. In spring the changes in size and distrubution of nuclei in leaf primordia were obvious. In the shoot tip periclinal divisions in dermal layer of cells were observed. In needle primordia mitotic spindles were orientated in the way of primordia elongation, with few anticlinal mitoses in mid-cortex. In buds of P. abies from in vitro culture there were adventitious buds situated between the needle primordia. There were anticlinal and periclinal divisions. The mitotic index (MI) in the embryonic shoot grown in vivo multiplied with the beginning of spring: in two weeks MI increased from 3.6x10-3 to 44.1x10-3. In the buds of P. abies grown in vitro the mitotic index kept quite continuous level, from 3.3x10-3 to 2.9x10-3 and in isolated adventitious bud of P.abies the mitotic index was 5.8x10-3.

Picea abies; mitotic index; mitotic phases; vegetative bud; adventitious bud

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