HYDROGEN ION CONCENTRATION AND SEXUAL EXPRESSION IN LYCHNIS DIOICA L

Abstract

The acidity of various tissues of staminate and pistillate plants was detd. by the range indicator method. All plants tested were grown under identical conditions in the greenhouse or garden. Sections of living stems and flowers were compared microscopically. Stems of staminate plants were more alkaline than those of the pistillate. The xylem, sclerenchyma, and epidermis were consistently more acid than other stem tissues; the phloem and pith were more alkaline. Major tissues of staminate flowers were more acid than those of the pistillate. Ovules and vascular strands connected with them were consistently more alkaline than other tissues of the ovary. No general pH range differentiated staminate from pistillate flowers except by reference to individual tissues. Comparative tests made potentiometrically on the expressed sap of the entire plant above ground, minus flowers and buds, showed that the staminate plants were more acid in all stages of blooming. Pre-blooming, blooming, and post-blooming stages were tested. No differences existed in either the pre- or post-blooming stages. Both sexes showed an increase in acidity with the inception of flowering and a continued increase with age; the young blooming plants were less acid in all cases. No correlation was noted between any definite pH and the sexual expression although clear cut differences were shown in comparative tests made on the 2 sexes.