Pollination causes increases in FW [fresh wt] and DW [dry wt] of Cymbidium ovaries and gynostemia. It also initates FW losses in perianth segments. Auxin (NAA) [naphthaleneacetic acid] applications to the stigma have the same effects except that FW of ovaries decreases. All segments of unpollinated flowers increased in DW, whereas FW variations were minimal. These weight changes reflect the aging and subsequent death and/or redifferentiation and further development of pollinated and/or unpollinated orchid flowers.

Seeds of C. aurantiaca grown asymbiotically on a medium containing sucrose as the sole source of organic carbon developed into leaf-bearing plants. Those sown on the same medium without sugar reached the protocorm stage but did not differentiate further. Cross transfers of seedlings between the 2 media indicated that following 21-30 days of growth on the sucrose-containing medium, subsequent development may proceed in the absence of sugar. Levels of chlorophyll and ribulose-1,5-diphosphate carboxylase were monitored and related to the ability of young seedlings to photosynthesize. A direct relationship between chlorophyll content and photosynthesis was not found. Increases in the activity of the enzyme were closely paralleled by increases in photosynthesis. A direct relationship was not found between chlorophyll a/b ratios and photosynthetic capacity. Germinating seeds and seedlings grown in the absence of exogenous carbohydrate were unable to convert appreciable amounts of labeled acetate to sugar.