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TO T IPO T EN CY AND M O R PH O G EN E SIS O F PLANT C E L L S

IN V IT R O

THE PECULIARITY OF MORPHOGENESIS

OFPICEA OBOVATA

ZYGOTIC

EMBRYOS IN CULTURES

IN VITRO

I.N.Tretyakova, I.P.Plillippova

V.N, Sukachev Institute of Forest, 660036, Krasnoyarsk, Academgorodok,

E-Mail:

dndr@tfoKkrasnoyarsk.su

The realization of morphogenetic possibility of organisms being

determined by totipotency of its cells occurred at cultivation

in vitro

of Picea

obovata zygotic embryos on medium containing 1 mg of 6-BAP per 1 liter.

The essential histological changes in embryos are observed on the 3-rd

cultivation day: in subepidermal hypocotyl cells periclinal cell dividing appears.

M itotic index was 8.4%.. Proliferation of new cells in hypoderm occurs on

the 5-th cultivation day. The groups of small cells with density cytoplasm

are formed. Mitotic index increased up to 25%.. Cell dividing in the root

meristem stops in this period. Meristem cells run through active differentiation

and become old. The root cap gets features of adult root cap cells that have

finished their growth. Starch grains disappear in cap cell amyloplasts. The

localized organogenic parts are formed under epidermal hypocotyl layer on

the 10-th cultivation day. The cells of these parts are characterized by small

size, intensive accumulation of protein and nucleic acids in nuclei and

cytoplasm as well as by limited vacuolization and by absence of starch.

M itotic index made 46,3%. On the 14-th cultivation day the nature of

histological variations is Kept and organic areas with meristem activity appear

above the hypocotyl surface. The explants which have been cultivated with 6

BAP during 21 days on the medium without hormones formed 25-30

adventitious buds per embryo.

Thus, the study revealed the localized cytokinin - induced meristem

activity which leads to de novo bud forming from zygotic embryos of P.

obovata in culture

in vitro.

Consequence of events is follow ing: 1 -

dedifferentiation of embryo cells, 2 - appearing of cell clusters, 3 - origin of

meristematic centers on hypocotyl, 4- formation of needle primordium, 5 -

formation of adventitious buds.

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