2014 Volume 83 Issue 2 Pages 160-164
The effects of atmospheric oxygen concentrations on germination and elongation of hypocotyl and radicle in three species of weedy morningglory, entireleaf (Ipomoea hederacea (L.) Jacq. var. integriuscula A. Gray), threelobe (I. triloba L.), and pitted (I. lacunosa L.) morningglory were studied by a simplified method using a small vessel, in which the atmospheric oxygen concentration was controlled by replacement with argon gas. In this method, the actual oxygen concentration in the treatment that was assumed to be 0% was actually 0.62%. It was impossible to make a completely anaerobic condition in this way. Pitted morningglory germinated in a wide range of oxygen concentrations, and approximately 30% of threelobe morningglory germinated at 0% oxygen concentration. The germination of entireleaf morningglory was inhibited by the treatment with 0% and 1% oxygen in the same way as in soybean cv. Fukuyutaka as a control. Elongation of radicle and hypocotyl of entireleaf morningglory at 4 days after sowing was markedly inhibited at lower concentrations of oxygen. Thus, there was interspecific difference in germination at a lower oxygen concentration among tested morningglories. The present gas replacement method might be convenient for testing germination under a controlled atmospheric oxygen concentration for understanding wet damage of crops.
