PHOTOSYNTHESIS IN CALLUS-CULTURES OF CHOISYA-TERNATA (RUTACEAE)

Photomixotrophic callus cultures of Mexican Orange (Choisya ternata HB K) containing about 100 mu g chlorophyll g(-1) fresh weight, were grow n under various light regimes on a medium containing 41 mM glucose as the sole organic compound. O-2 and CO2 exchanges were simultaneously r ecorded during a culture cycle. The data showed that the cells were ph otosynthetically active and switched from photomixotrophy to photoauto trophy after glucose had been used up and the culture medium was free of any organic compound. The cells were also grown under strict photoa utotrophic conditions for 6 months under continuous light and 2% CO2 w ith monthly subcultures.