Morpho-anatomical studies in vegetative organs of Cordyline fruticosa (L.) Chevalier, C. australis (G. Forst.) Endl. and C. spectabilis Kunth & Bouché.

• Grant number: 11/15669-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2012
• End date: March 31, 2014
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Nanuza Luiza de Menezes
• Grantee: Karen Lucia Mayumi Sasaki
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The genus Cordyline presents controversies about its classification, today it belongs to the Asparagaceae family. C. spectabilis is the only species of the genus native from Brazil, while C. fruticosa and C. australis are exotic species and they are commonly used in landscaping. In the beginning of the 20th century, K. Goebel refered to Dioscorea, Cordyline terminalis, C. australis and Selaginella as having in common an intermediary structure between stem and root which allowed the formation of a richer root system. In Selaginella, that structure was called rhizophore ("root bearer") by C. Nägelli and H. Leitgeb in 1868. In the end of 20th century, N. L. Menezes found an equivalent structure in Vernonia, and by coincidence and by analogy to Selaginella, also called it rhizophore. Then, a new line of research started with the objective to verify the true nature of root formative subterranean organs of some angyosperms. Besides, monocotyledons are objects of studies attempting to clarify how their stems thicken. Commonly attributed to a primary thickening meristem (PTM), this growth in thickness is related to the boundary region between the cortex and the vascular cylinder. Recently there is a new interpretation to this boundary region: instead of being a new tissue, the endodermis and the pericycle would be responsible for the primary thickening. It would be this endodermis with meristematic activity that originates part of the cortex, and the pericycle would form the vascular tissues. In C. fruticosa it was demonstrated that the pericycle would still be the responsible for the formation of the secondary thickening meristem (STM). The objectives of the present work are: to verify the true nature of Cordyline species' subterranean organ by studying its origin, and analyse their thickening features.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SASAKI, Karen Lucia Mayumi. Morphoanatomical studies in vegetative organs of Cordyline fruticosa (L.) Chevalier, C. australis (G. Forst.) Endl. e C. spectabilis Kunth & Bouché. 2015. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) São Paulo.