Abstract
Some oat plants with 40∼42 chromosomes (2n) were grown in a greenhouse, controlled at 19.4°C for around eight months from September, 1965 to May, 1966. These plants, especially aneuploids, were sterile or extremely low fertile in two harvest periods, prior to March 2 and March 2 to March 30, but moderately fertile in the period from March 31 to May 12. The fcrtility variation seems to be influenced by minor changes in climatological factors, especially sunlight imensity. It is generally said that the aneuploids are more susceptible to low temperature, e.g. 19.4°C, than plants with normal chromosomes nurnber.
