Abstract
The cobalt, copper and nickel contents of various floral tissues of Lilium longiflorum were determined polarographically at consecutive three stages. The cobalt content of the pistillate tissues, except for the ovary, of young flower bud was apparently different from the corresponding values obtained with mature flower bud and with pollinated flower. As differentiation of the flower bud proceeds, there was a marked increase in the amount of cobalt in both the stigma and the style; on the contrary, no significant change of copper and nickel contents in either the stigma or the style was found. However, the style of pollinated flower exhibited a significant decrease in cobalt when compared with that of mature one. The cobalt content in the style from pollinated flower was about half of the value found in the style from mature one. In the case of ovary, the contents of cobalt, copper and nickel remained constant and almost unchanged during the growth and the subsequent pollination periods. On the other hand, the cobalt content of the pollen grains was far less than those of the stigma and style. In some cases, the amount of this metal of the pollen grains was about one-eighth of the value for the mature style. It is suggested that the cobalt may bear a functional relationship to the stylar metabolism and the growth of pollen tubes.
