32 赤松の花粉發芽に就て
スポンサーリンク
概要
- 論文の詳細を見る
The pollen of Pinus densiflora SIEB. et ZUCC. which was set in VAN TIEGHEM moist chamber began to germinate by pouring over fresh water drop (pH 5.8-6.0) in 48 hours in the thermometry adjusted to maintain the temperatue at about 25℃. In 7 days, some of the pollen tubes grew to 127 microbes and germination percentage became 80 %. Nearly the same results were found on distilled water drop with 3 percent sugar, but the more increased the percentage of sugar in solution, the worse found the effect on germination.As to the concentration of hydrogen ions of germination culture fluid, the pollen was injured by the solution, acidified below pH 3.4 by citric acid. The more the acidity of culture fluid weakened, the better germination result were observed. In the case of pH 6.0,the pollen tubes were recognized in 48 hours and some of tem elongated to 164 microbes in 10 days.As a medium for the pollen germination test of Pinus densiflora, ager gel is excellent too. Germination results on 3 percent agar gel which was qualified by citric acid from pH 3.6 to pH 6.2,did not make remarkable differences. On the culture medium pH4.4 in the moist chamber of Petri dish, pollen tubes appeared in 24 hours at about 30℃. and 48 hrs. at about 25℃. Some of the pollen tubes grew to 150 microbes in 5 days.Sometimes pollen tubes appeared simultaneously from both opposite sides of the pollen between two air-sacks and often branched into two or three at the end.The concentration of hydrogen ions of the nucellus of Pinus densiflora was indicated to be about pH 3.0 really in nature just after the flowering time and gradually changed into pH 5.6 by August. From August to the middle of April next year, the acidity of the nucellus was nearly constant and afterwards nuderwent the similar process as in the previous year.From the results of above experiments, it may be concluded that it is not because of the acidity of the nucellus which keeps the pollen from germinating in the flowering year.The pollen germination on Pinus densiflora nucellus in nature was really recognized in Tottori in the latter part of June 1949,when the concentration of hydrogen ions of the nucellus was pH 5.0-5.2,and the mean temperature at 10 a. m. on the field was 22°.2C.
- 1950-06-25