Effect of Ethylene and Carbon Dioxide on Seed Germination of Monochoria vaginalis var. plantaginea.

Abstract

The relationship between seed germination of Monochoria vaginalis var. plantaginea and gas composition in soil, i. e. ethylene, CO2, O2 and their combination was studied. A high germination percentage was obtained in the presence of both ethylene and CO2 regardless of the storage conditions, but in the presence of absorbents for both ethylene and CO2 the germination percentage declined significantly (Fig. 2 and Table 1). In the presence of CO2 absorbent, the application of ethylene to seed increased the germination percentage , while the effect of exogenous CO2 with the absorbent of ethylene on seed germination was very little. However, the germination percentage was increased by exogenous CO2 if the concentration was sufficiently high (Table 1). The effect of ethylene on seed germination of Monochoria may more important than that of C02i and the seed germination is considered to be increased by endogenous ethylene. The seeds under 60% oxygen exhibited a significantly decreased germination percentage while under 0. 2% oxygen they showed high germination. No seeds, even non-dormant seeds, germinated in a petri dish with a filter paper in the presence of 21% oxygen (Fig. 1). The results demonstrate that Monochoria seeds require very little oxygen for germination.