乾燥種子の浸水による発芽の低下について

抄録

It has been shown that soaking injury to seeds of the kidney bean, soy-bean, pea, rice, wheat, rye, and barley causes a change in the amount of water the seeds contained before soaking in water. The seeds which absorbed various amounts of water by placing in desiccators or moist chambers were soaked in tap water filtrated through the ion-exchange resin and kept at 25℃. for two to ten hours. At the termination of the soaking period the water was drained off and the seeds were placed for germination tests on moist filter papers in room temperature or in soil under greenhouse conditions. Dry-seeds showed a decrease in germination capacity as a result of soaking in water for several hours, but by increasing their water contents in the moist chamber, they showed normal germination after the soaking process. Therefore, the harmful effect to dry-seeds is not by dry treatment but by soaking in water. Seeds of the kidney bean and soy-bean having the water content less than 9.5-10.5 per cent showed a decrease in germination and in those with less than 4.5-5.5 per cent water could not perfectly tolerate for more than two hours of submergence in water at 25℃. There was no difference between the effect of soaking in water for two hours than that for four to ten hours. Soaking injury to dry-seeds commences at an early period of soaking in water. Dry-seeds showed cotyledonal-cracking as a result of soaking in water, but by increasing their water contents in the moist chamber, they showed no cracking after the soaking process. Dry-seed cracked during soaking in water for two hours. The rate of water absorption during soaking in water by dry-seeds was faster than that by the other seeds. From these experiments it seems likely that the soaking injury of dry-seeds occurs as a result of cracking of the seeds by rapid absorption of water during the soaking period.