THE INDUCTION AND PINE STRUCTURE OF GRAPEVINE CELLS (VITIS-VINIFERA) CULTURED IN-VITRO

The development of in vitro cultured Monastrell grapevine (Vitis vinif era) cells was related with the two periods of rapid fruit growth, dur ing which the ability of fruit explants to develop callus tissues was maximal. For all ages, the de-differentiation process was mainly locat ed in mesocarp tissues, while the hypodermal tissues appeared to be re calcitrant to de-differentiation. After optimization of growth in the dark, the optimal hormonal conditions were 1.0 mu M kinetin and 0.5 mu M alpha-naphthaleneacetic acid. Calli grown in light or darkness did not show anthocyanin accumulation. Electron microscope studies reveale d that cells cultured in suspension showed to be highly vacuolated wit h their cytoplasm reduced to a very thin peripheral layer where ER mem branes were not prominent. The cytoplasm layer contained a high popula tion of Golgi sacks. This last observation is consistent with the inte nse protein secretory activity showed by these cell cultures.