Determination of Shoot Apical Meristem and Plumule Organization in Rice Embryos : Light and Electron Microscopy

[摘要] Transmission electron microscopy revealed that a shoot apical meristem showed the first sign of organization at 3.5 DAA (days after anthesis), soon after an indentation by an incipient coleoptile on the upper ventral surface of the rice embryo. The demarcation of the meristem was terminated by a small depression on the lower surface at 4 DAA and then by periclinal divisions at 4.5 DAA. After that, the tip of the coleoptile gradually covered the apical meristem, making a notch of great depth, and the edges of the coleoptile rose along the periphery of the meristem, As a result, these events were conducive to the bilateral symmetry of the embryo. At 5 DAA, the coleoptile was overarching the apical meristem. At 8 DAA, the meristem was completely enveloped by the coleoptile and the first and second leaves, resulting in the formation of a plumule. The ventral organization of the shoot apical meristem is discussed in relation to somatic embryogenesis of rice as it is currently mentioned.

[学科分类] 农业科学（综合）

[关键词] Coleoptile;イネ;Embryogenesis;茎頂分裂組織;Oryza sativa;子葉鞘;Plumule;胚発生;Shoot apical meristem;微細構造;Ultrastructure;幼芽