抄録
1. The authors investigated the artificial germination of sugar beet pollen on cultural media, using the pollen of Variety "Hon-iku No. 398" at the flowering time in 1950. 2. In the case of common cultural media, the best result was obtained when it consisted of 25 % sucrose and 1 % agar. But, on the whole, the percentage of germination was very slight (less than 25 % at maximum) in ordinary media. 3. The addition of "boric acid" to the cultural media promoted the germination very extensively, and the dose of" boric acid" at the rate of 0.005 % concentration was most favorable. 4. The optimum PH value for pollen germination was 4.6. 5. Consequently, the cultural media of PH 4.6 and containing 0.005% of "boric acid" induced the successful germination of 8.0%. 6. In the case of cultural media using "organic acid" and "pepton", an application of "citric acid" and "tartaric acid" some degrees (about 20 %) and, "pepton was most effective showing germination percentage as much as 50 %, while the control plot showed about 14 %. 7. The length of pollen tube elongated more vigorously and velocity of pollen tube growth became faster when the "boric acid" was added to the cultural media. 8. No germinated pollen was found in the distilled water when used as cultural media. But the germination percentage was as high as about 30 % when the water contained 0.005 % "boric acid". 9. In the investigation on vitality of sugar beet pollen, the germinating percentage decreased remarkably on the 4 th day and none was obtained on the 7 th day, when the pollen was wrapped up in parchment paper and stored in the room.
