Wilms F H A, Sassen M M A
Department of Botany, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen, The Netherlands.
New Phytol. 1987 Jan;105(1):57-65. doi: 10.1111/j.1469-8137.1987.tb00109.x.
Initiation and formation of floral buds was studied on explants of Nicotiana tabacum. During the first stage of development (0 to 4 d), protrusions are formed at the basal side of the explant as a result of cell divisions in both sub-epidermal and epidermal cell layers. The second stage (4 to 7 d) is characterized by the formation of tracheary centres inside the protrusions followed by the formation of floral primordia at the surface of the protrusions. These primordia result from both epidermal and sub-epidermal cell divisions. In the final stage (7 to 15 d), flower primordia develop into flower buds and tracheary elements grow into the buds. Polarity present in cells of freshly cut explants is lost within a few days after the onset of the experiment. After 4 to 7 d, a new polarity axis has differentiated inside the protrusion. This axis runs from the tracheary structure inside the protrusion to the flower primordium at the periphery.
对烟草外植体上花芽的起始和形成进行了研究。在发育的第一阶段(0至4天),由于表皮下和表皮细胞层的细胞分裂,在外植体的基部形成突起。第二阶段(4至7天)的特征是在突起内部形成管状中心,随后在突起表面形成花原基。这些原基是由表皮和表皮下细胞分裂产生的。在最后阶段(7至15天),花原基发育成花芽,管状元件长入芽中。刚切割的外植体细胞中存在的极性在实验开始后的几天内丧失。4至7天后,在突起内部分化出一个新的极性轴。这个轴从突起内部的管状结构延伸到外围的花原基。