Basal Meristem and Root Development in Isoetes asiatica and Isoetes japonica
Basal Meristem and Root Development in Isoetes asiatica and Isoetes japonica
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亚洲水韭和日本水韭的基部分生组织和根系发育
DOI：
10.1086/322942
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发表时间：
2001
影响因子：
2.3
通讯作者：
Masahiro Kato
中科院分区：
文献类型：
--
作者：
S. Yi;Masahiro Kato
为了更好地了解水仙这一神秘器官，我们对亚洲水仙和日本水仙的基本分生组织和根的发育进行了解剖研究。根状茎的基生(生根)分生组织与侧生分生组织是连续的，两者都构成一个分生组织。基本分生组织具有一层薄的首字母，既有器官发生的属性，也有加厚的分生组织属性。这些属性的组合表明，基本分生组织在包括形成层在内的维管植物分生组织中是独特的。根原基由3~4个放射状细小的幼小衍生细胞组成，其主体由三层顶端分生组织组成。与根不同，原基产生少量的衍生细胞以及原形成层和未来的根冠，它们不形成皮层和表皮。在发育成根之前，原基通过基分生组织的皮质组织的进一步发育和表面细胞的脱落而向球茎表面移动。这种独特的发育模式是通过第二个胚根的亚内源和第三个胚根的内源建立起来的。比较了冬虫夏草的分生组织和根的发育模式，并与卷柏根柄的分生组织和根发育模式进行了比较。这种比较似乎不支持将根解释为叶的同源物。
We studied the anatomy of the basal meristem and root development in Isoetes asiatica and Isoetes japonica to better understand the Isoetes rhizomorph, an enigmatic organ. The basal (root‐producing) meristem of the rhizomorph is continuous with the lateral meristem, and both comprise a single meristem. The basal meristem with a layer of thin initials has both organogenetic and thickening meristem attributes. A combination of these attributes indicates that the basal meristem is distinctive among the vascular plant meristems, including cambium. The root primordia develop from young derivative cells organized in three to four radial fines, and their main body is composed of a three‐layered apical meristem. The primordia, unlike the roots, produce a small number of derivative cells as well as a procambium and future root cap, and they do not form a cortex and epidermis. Prior to developing into roots, the primordia are shifted closer to the corm surface through further development of cortical tissues from the basal meristem and sloughing of surface cells. This unique developmental pattern is established through the subendogenous origin of the second embryonic root and the endogenous origin of the third root. The meristem and pattern of root development in Isoetes is compared with that indicated for the lepidodendrid and isoetalean rhizomorphs and contrasted with that in the Selaginella rhizophore. The comparison seems not to support the interpretation of the roots as leaf homologues.