摘要
黄瓜幼苗分别培养于诱花和诱导营养芽培养基后，逐日进行了交换培养基试验，并在培养开始２ ｄ 后去顶。诱导营养芽培养基中培养１ ～６ ｄ 后转入诱花培养基，成花率依次递降，７ ｄ 后再转成花率极低。诱花培养基中培养少于５ ｄ 即转诱芽培养基，成花率极低；培养６ ｄ 则跃增；并随诱花培养基中培养天数增加而成花率上升，直至１８ ｄ 达顶点。表明：培养１ ～５ ｄ 期间，诱花培养基作用不明显，诱花培养基的有效作用期为６ ～１２ ｄ（ 去顶后的４ ～１０ ｄ） 。
Seventy eight groups each of 10 5 day old cucumber seedlings were planted separately in flower induction medium (KNO 3 0.01 mmol/L, CaCl 2 1.0 mmol/L,KH 2PO 4 1.0 mmol/L,MgSO 4 1.0 mmol/L,Fe salt of 1/3MS level, other microelements at 1/3MS level,and PP333 0.75 mg/L) and vegetative bud induction medium (the same as the above except that KNO 3 0.01 mmol/L was replaced by KNO 3 4.0 mmol/L and PP333 by GA 3 1.0 mg/L) (the seedlings were decapitated after culturing for 2 days). Then the cultures were transferred from one medium to the other,6 groups/day,until the 12th day to determine the critical period of flower transition and floral reversion. The results are as follows: (1)The percentage of flower formation decreased from 70% to 20%when the duration of vegetative bud induction medium pretreatment before transferring seedlings to flower induction medium was prolonged from 1 day to 6 days. The flower formation percentage was very low when the vegetative bud induction medium pretreatment was prolonged to 7 days(Table 1,Fig.1). (2) The flower formation percentage was very low when the duration of flower induction medium pretreatment was less than 5 days before seedlings were transferred to vegetative bud induction medium.The flower formation percentage shifted to 27% when the flower induction medium pretreatment was prolonged to 6 days.The percentage of flower bud formation was increased to 83% when the flower induction medium pretreatment was carried on for 18 days(Table 2,Fig.3). The results indicate that the flower induction medium pretreatment during the first 5 days was ineffective. The critical period of the effect of flower induction medium is the 6th day or the 4th day after decapitation. The period in which flower induction medium pretreatment is effective is 4th～10th day after decapitation.
基金
国家自然科学基金
浙江省自然科学基金
关键词
黄瓜
去顶苗
交换培养基试验
花决定临界期
decapitated cucumber seedling, transfer experiments, critical period of floral determination
