抄録
It has previously been shown by the writer that the weakness of dehiscing power of anther is the most critical factor governing the incidence of sterility in barley. An attempt was made to measure the dehiscing power from the physical points of view. For this purpose, two factors, namely the velocity and weight of pollen grains were measured on the plants sown at three widely separeted dates in the spring. The velocity, presented in the order of sowing date, was 13.9, 9.8 and 6.3 cm/sec, respectively. The weight of pollen grain was determined by two different methods, (1) subtracting the weight of empty anther from that of the same filled with pollens, and dividing the remainder by the number of pollens, (2) multiplying the specific gravity by volume of pollen grain. The first and the second method gave approximately similar results. The weight of a single pollen was (110, 122 and 96) x 10-9 gr. respectively. Since two factors, velocity and weight, were obtained, the momentum of pollen was calculated as the product of these two factors. Representing the momentum with ratios of integer, it was found as 2.5 : 2.0 : 1.0, and obviousey corresponded in close negative correlation to the sterility percentage; 7.1, 12.5 and 31.1.
