[Patterns in the cellular organization of ovule growth in the pine, Pinus silvestris L. II. Growth processes in nucellus and integument].
The dynamics of growth processes was studied in the integument and nucellus of Pinus silvestris during the year of fertilization. The growth of two parts of the nucellus and integument under study is described by an S-shaped curve but the dynamics of growth processes and the ratio of cell reproduction and elongation differ in each tissue. The growth of micropylar part of the nucellus and integument proceeds, mainly at the expense of cell proliferation. At the first stages of growth the cell size remains constant, then during a short period the reproduction and elongation of cells occur simultaneously, and after the fertilization the growth proceeds at the expense of cell elongation only, since the cell division arrests completely. In the part of nucellus concrescent with the integument, the mitotic activity disappears still prior to fertilization and the growth proceeds, mainly, at the expense of cell elongation. Differences in the cell size are observed both between tissues and between different regions of the same tissue. The larges nuclei are situated in the micropylar part of nucellus. The nuclear size suffers insignificant changes during the growth of the tissues under study.
D006128:Growth; D014197:Trees
Nekotorye zakonomernosti kletochnoĭ organizatsii rosta smiapochki sosny Pinus silvestris L. Soobshchenie II. Rostovye protsessy v nutselluse i integumente.