烟草花柄离体培养中花芽分化的细胞起源观察

ORIGIN OF FLORAL BUDS IN TOBACCO PEDICELS CULTURED IN VITRO

Histocytological observations on thin cell layers (TCLs) and segments of the pedicels of Nicotiana tabacum L.cv.GeXing 1, cultured on Murashige and Skoog medium with indolebutyric acid (IBA) 2mg/L and 6-Benzylaminopurine (6-BA) 0.2mg/L, were carried out during the first 16 days of culture with light microscopy. The first eight days of culture were characterized by the enlargement of cells (mainly in corlical cells)and cell division regions formed in subepidermal, cortical cells (in TCLs and segments) and vascular cambium cells (in segments). These cell divisions led to the formation of cell divi- sion centers. In the 12th day of culture, flower buds were visible. Slices showed that flower buds arose from the subepidermal cells. The cell division centers formed by cortical cells (in TCLs and segments) and vascular cambium cells (in segments) may also be the origin of flower buds.