[Patterns in the cellular organization of ovule growth in the pine, Pinus silvestris L. II. Growth processes in nucellus and integument]. / Nekotorye zakonomernosti kletochnoi organizatsii rosta smiapochki sosny Pinus silvestris L. Soobshchenie II. Rostovye protsessy v nutselluse i integumente.

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.

[Patterns in the cellular organization of ovule growth in the pine, Pinus silvestris L. I. Growth processes in endosperm]. / Nekotorye zakonomernosti kletochnoi organizatsii rosta semiapochki sosny Pinus silvestris L. Soobshchenie I. Rostovye protsessy v éndosperme.

The dynamics of growth processes was studied in the endosperm of Pinus silvestris during the year of fertilization. The growth of endosperm is described by an diauxic curve where the period of delay corresponds, by time, to fertilization. The growth of tissue proceeds, mainly, at the expense of cell proliferation. The mitotic activity is preserved in the endosperm till the beginning of formation of reserve substances in the cells; cell division and elongation occur simultaneously. The unfavourable environmental conditions influence the mitotic activity of cells only. The size of fully grown cells is relatively constant and somewhat decreases later, during maturation. One can distinguish rather early those regions in the endosperm where the cell size is 2-3 times less than in the rest tissue; the size of cells and nuclei in these regions suffers only insignificant changes during the growth. The large nuclei are observed in the beginning of the cell endosperm formation and, then, their size decreases 1.5-2 times; the second increase in nuclear size in the endosperm is observed during the period prior to the formation of reserve substances.

Embryonal antigens in maize caryopses: The temporal order of antigen accumulation during embryogenesis.

The sequential appearance of a specific group of embryonal antigens (EA), presumably globulins, was demonstrated in developing maize (Zea mays L.) caryopses using a double immunodiffusion test with absorption of common antigens. Cross immunoelectrophoresis was employed to follow the differential pattern of EA accumulation in the growing scutellum and embryonic axis. The transient nature of two predominant EA seems to indicate their role as specific protein reserves of embryonal tissues. Another presumably organ-specific EA was maintained in callus obtained from a 28-day-old culture of scutellum isolated from the mature non-germinated caryopsis.