シバ類種子の発芽性に関する研究

The germinability of the seed of zoysia grasses (Zoysia japonnica, Z, matrella) shows some characteristics of wild grasses, while it shows a fairly great individual variations. These studies have been made in order to see if their seeds retain the nature of the wild grasses of germinating sporadically over a long period of time, and also to know their length of life. The followings are the results.<BR>1) The seeds have a fairly long life in the case of ordinary dry storage. They still have enough germinability even after 16 years. The germination percentage is low at the beginning, and suddenly goes up in the 2nd year. After the 2nd year it gradually goes up until 7-10th year. The highest percentage exceeds 50 per cent. Then it begins to go down. This shows that their germinability is sporadical over a long period. How the number of days needed for the first seed to start germinating change with years is not clear, but the trend is generally the same as the above.<BR>2) Treatment for the germination: Physical methods do not seem to be effective while a few chemical ones are found quite effective.<BR>3) Keeping of the seeds: They can be kept in the best condition in a desicator. The alcoholic treatment for the selection of ripening seeds does not seem to affect the germination.<BR>4) The seeds complete the suction in 3 or 4 days at the latest. The stored seeds show the decrease of weight (of moisture) of 90 to 95%, while those left alone show the decrease of 100-104%. Those kept in a refrigerator show 98 to 100% decrease after one year, and after that exceed 100%. These percentages are considered to have some relationship with the length of life.