Abstract
This paper deals with the results of germination tests of pollen in broad bean. Four varieties, Osaka Issun, Ryosai, Kyuryu and Saitama Wase, were used in spring, and one variety, Izu Wase, was used autumn in 1958.
1. The artificial medium containing 1% agar and 10% sucrose was most suitable for the pollen germination (i.e., for germination percentage and elongation of pollen tubes) and the optimum hydrogen on concentration was 7.0. But it seems that favourable ranges of the three factors were not strictly restricted, but were pretty wide.
2. The varietal differences in germination percentage of pollen were hardly recognized among the four varieties used in the spring tests.
3. The suitable temperatures for the pollen germination were 10_??_20°C.
4. The germinability of pollen showed considerable differences according to the stages of bud development from which the pollen was gathered.
5. The germination of pollen was retarded when the flowers were soaked in water for a long time (longer than 20 minutes). If the temperature of water was high (40°C), the pollen did not germinate even if the time of soaking was short (5 minutes).
6. Though each of high temperature and high moisture retarded the germination of pollen, the retardation effects were more remarkable when the both factors acted simultaneously.
7. The germination ability of pollen was reserved considerably long time; for instance, it was maintained for three to four days when the flowers were placed in the room.
