|
|
||||||||
2Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Tokyo 112-8681, Japan; and 4Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
We describe the unique development and branching of lobed thalli in Hydrobryum japonicum. Lobe formation begins with meristem initiation at random sites near the thallus margin fringed by protective tissues. As the protective tissues are successively peeled off particularly in the growing new lobes, the lobes become naked and then become fringed again by new protective tissues that develop from the marginal part of the new meristems. Subsequently the meristems become less active and are differentiated into parenchymatous ground tissue at maturity. The random pattern of meristem formation during the sporadic development gives rise to a nonorderly branching pattern of the thalli. Some other lobes (
10%) are regenerated from injured parts of the thalli. The vegetative shoots arise endogenously near the thallus margin and are enclosed by the nonvascular strand nets. The rudimentary shoot apices remain embedded in the thalli. The thalli, though remarkably different from typical roots of other angiosperms, might be extremely transformed roots.
Key Words: developmental morphology homology Hydrobryum japonicum meristem Podostemaceae root root cap shoot
This article has been cited by other articles:
![]() |
C. Heimsch and J. L. Seago Jr. Organization of the root apical meristem in angiosperms Am. J. Botany, January 1, 2008; 95(1): 1 - 21. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Koi, R. Fujinami, N. Kubo, I. Tsukamoto, R. Inagawa, R. Imaichi, and M. Kato Comparative anatomy of root meristem and root cap in some species of Podostemaceae and the evolution of root dorsiventrality Am. J. Botany, May 1, 2006; 93(5): 682 - 692. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. IMAICHI, Y. HIYAMA, and M. KATO Leaf Development in the Absence of a Shoot Apical Meristem in Zeylanidium subulatum (Podostemaceae) Ann. Bot., July 1, 2005; 96(1): 51 - 58. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. KOI and M. KATO Comparative Developmental Anatomy of the Root in Three Species of Cladopus (Podostemaceae) Ann. Bot., June 1, 2003; 91(7): 927 - 937. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. HIYAMA, I. TSUKAMOTO, R. IMAICHI, and M. KATO Developmental Anatomy and Branching of Roots of Four Zeylanidium Species (Podostemaceae), with Implications for Evolution of Foliose Roots Ann. Bot., December 1, 2002; 90(6): 735 - 744. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. SUZUKI, Y. KITA, and M. KATO Comparative Developmental Anatomy of Seedlings in Nine Species of Podostemaceae (Subfamily Podostemoideae) Ann. Bot., June 1, 2002; 89(6): 755 - 765. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |