||In order to elucidate the correlation of tempe rature and the effect of gibberellin spray on the development of flower-buds in Cryptomeria japonica cultivar Kumotooshi, experiments were done in contro...lled environmental condition during 1970-1971. The following points were observed: 1. The male flower-buds were formed maximum in the temperature range of 25℃-30℃ and their formation decreased with the decrease in temperature. On the other hand, the female flower-buds were formed maximum in the temperature range of 20℃-25℃. At 15℃ the both flower-buds were hardly differentiable. At 33℃, they were differentiated, but soon they changed into leaf buds and chlorosis was observed. 2. Male and female flower-buds were formed even at temperatures lower than the optimum ones when sprayed with gibberellin. 3. The effects of the temperature treatment was most predominant at the early term (May 10-Jun. 24) of differentiation in both male and female flower-buds. 4. Under alternating temperature condition the male flower-buds were formed maximum when the mean temperature was around 30℃, and around 20℃, the female flower-buds were formed maximum. 5. Neither male nor female flower-buds were formed at constant temperature treatment (33℃) in the whole period (May-September). However, with a short time treatment at 33℃, the flower-buds were formed in both cases of constant and alternating temperatures. 6. Even at 30℃, the male flower-buds were formed after the samples were treated at the low temperature (chilling) in winter. This result suggests that chilling as a pretreatment is essential for the flower-bud formation and both adequate temperature and day length conditions can control the flower-bud differentiation period.
スギのさし木クローンであるクモトオシの花芽の分化・発達におよぼす温度とジベレリン処理の効果を明らかにするために,1970年5月から71年3月まで環境制御条件下で行なった実験の結果,つぎのことが観察された. 1. 通常の花芽分化期(夏季)において,雄花芽は 25℃～30℃ の温度範囲で最も多く形成され,温度の低下につれて減少した.一方,雌花芽は 20℃～25℃ の範囲で最も多かった.15℃ では両花芽とも分化せず,33℃ では雄花芽は分化したが,間もなく葉芽に転換し,しかも,それはクロロシス現象を起こした. 2. ジベレリン(GA 3)で処理すると,雌・雄両花芽ともそれぞれの適温より低い温度でも形成された, 3. 温度処理の効果は,雌・雄両花芽ともに分化の初期(5～6月)の処理で最も大きかった. 4. 変温処理の効果は,雄花芽はその平均温度が30℃ 付近で,雌花芽は20℃ 付近で最も大きかった. 5. 全分化期間(5～9月)の33℃ 恒温処理では雌・雄両花芽とも形成されなかったが,短期間の処理では,恒温・変温の両処理ともに効果があった. 6. 冬季の低温(冷温)処理後30℃ の恒温条件下で,3月にはすでに雄花芽の形成をみたが,これらのことから,花芽の形成には前処理として冷温処理が必要であり,しかも適当な温度と日長条件が与えられれば,花芽分化期の調節も可能であるということが示唆された.続きを見る