THE FAVORABLE EFFECT OF REDUCED OXYGEN SUPPLY UPON THE GERMINATION OF CERTAIN SEEDS

Abstract

A number of workers (I, 2, 3, 5) have shown that increasing the partial oxygen pressure of the atmosphere brings about or improves the germination of intact seeds of several species of plants. Work reported in this paper, however, shows that reducing the oxygen pressure has a very beneficial effect upon the germination of intact cat-tail seeds at a variety of temperatures, and a marked effect upon the germination of Bermuda grass seeds. With both cat-tail and Bermuda grass seeds, diluting the air with nitrogen or hydrogen favored germination. The optimum for cat-tail seeds was obtained by diluting the air with 40 to 8o percent of these gases, and for Bermuda grass with 40 to 60 percent. Cat-tail seeds germinated much better in atmospheres of one hundredth normal oxygen pressure than in normal oxygen pressure, but chlorophylldevelopment in the seedlings required greater pressure than this, namely, about 4 percent normal oxygen pressure. These results must not be taken to mean that reduced oxygen pressure will favor the germination of most seeds. It is probable that relatively few seeds are thus favored in germination.