STUDIES ON DIRECTLY REDIFFERENTIATING FLORAL BUDS BY EXPLANTS OF Hyacinthus orientalis L.——CONTROL OF MORPHOGENESIS OF FLORAL AND VEGETATIVE BUDS

The present work mainly deals with the control of redifferentiating of floral and vegetative buds by means of exogenous hormones and explants. The following results have been obtained: (ⅰ) When using young petals as explant, the medium supplemented with different hormones can induce to form distinct neoformations, 2,4-D can only induce the explant to form callus; 6-BAP can induce to redifferentiate vegetative buds; zeatin can induce directly to redifferentiate floral buds. (ⅱ) On the medium supplemented with zeatin, petal and floral stems can be induced directly to redifferentiate floral buds, while young leaves and bulbscales only to redifferentiate vegetative buds. (ⅲ) On the medium supplemented with zeatin, the petals excised from the floral buds formed by petals cultured in vitro can continuously redifferentiate the floral buds, but the young leaves excised from the young vegetative buds which were formed by petals cultured in vitro only redifferentiate vegetative buds. Experimental results show     

玉米花粉植株的诱导及其后代的观察

本文报道了近两年来玉米花药培养研究中所取得的主要实验结果。接种花药时花粉发育时期对诱导频率影响很大,单核中期诱导率最高,一般为3—7％,个别可达15.6％,各发育时期的花粉对15％的蔗糖都产生较好的反应,在诱导培养基中加入适当配比浓度的激素(2,4-D2毫克/升和激动素1毫克/升)及一定浓度的酪朊水解物(500毫克/升)和活性炭(0.5％)能明显提高诱导频率。通过花药压片和切片的显微镜观察,已见到2-4个细胞的花粉粒和多细胞团,同时也发现部分花药的药壁或药隔细胞活化和增生而形成愈伤组织,植株根尖压片染色体数多为10,证明是来源于花粉的单倍体植株,单倍体植株移入土中,经加倍处理后于1977年4月有一株同时抽雄、吐丝,通过人工自交授粉,于6月1日收获一个有65粒种子的果穗,7月下旬播种出苗后,又对其后代进行了比较观察。     

风信子外植体直接再分化花芽的研究——Ⅰ.花芽和营养芽形态发生的控制

本文研究外源激素和外植体对风信子花芽和营养芽再分化的控制。其结果为:(1)对花瓣外植体来说,培养基中附加2,4-D只能诱导形成愈伤组织;附加6-BA能诱导营养芽;附加玉米素能诱导直接再分化花芽。(2)在附加玉米素的培养基上,花瓣和花茎外植体能直接再分化花芽;幼叶和鳞片只能诱导再分化营养芽。(3)在附加玉米素的培养基上,从花瓣外植体再分化的花芽上分离的花瓣可以继续再分化花芽;从花瓣外植体再分化的营养芽上分离的叶切段只能诱导再分化营养芽。结果表明,对于诱导风信子外植体直接再分化花芽来说,培养基中附加玉米素和外植体必须取自花器官是两个关键因素。