Abstract Detail



100 years of Baileyan Trends – Wood Evolution, Function and Future

Frankiewicz, Kamil [1], Oskolski, Alexei [2], Fernandes, Francisco [3], Reduron, Jean-Pierre [4], Reyes Betancort, Alfredo [5], Banasiak, Łukasz [1], Spalik, Krzysztof [6].

Wood anatomy in secondarily woody carrots: Do paedomorphic traits result from mechanical constraints?

Umbellifer tribe Daucinae comprises mostly herbaceous species with the notable exception of few rosette treelets, recently transferred to the carrot genus (Daucus): Daucus decipiens (= Melanoselinum decipiens), D. edulis (= Monizia edulis), D. elegans (= Cryptotaenia elegans), and some species formerly placed in Tornabenea. Character mapping on molecular phylogenetic tree shows that all woody species of Daucinae are derived from herbaceous ancestors. According to Carlquist’s theory of paedomorphosis, secondarily woody species should exhibit juvenile traits protracted into mature secondary xylem. To check this hypothesis, we studied stem structure in 19 representatives of Daucinae, both woody and herbaceous. We found that among the paedomorphic wood traits sensu Carlquist only predominately upright and square cells in ray composition are common, while D. elegans shows also a delayed ray development. Another presumed paedomorphic trait, the scalariform intervessel pitting with wide pit apertures, was found only in D. edulis. Other than that, the secondary xylem of Daucinae is non-paedomorphic. The presence of upright and square ray cells can be explained by the fact that the studied species have a narrow wood cylinder; therefore, the formation of procumbent cells is hampered due to a limited radial growth. The delayed ray development in D. elegans results in stem reinforcement, which is much needed in this rosette treelet with slender stalk branching in its upper parts.   The scalariform intervessel pitting in D. edulis is probably associated with the parenchymatization of its wood, a feature related to plant life history. Monocarpic Daucinae tend to display fibrous wood, while polycarpic species exhibit pervasive axial parenchyma. Daucus edulis is a perennial monocarpic rosette treelet and its unbranched stem contains highly parenchymatized wood at vegetative stage. The onset of the flowering stage and the production of numerous lateral stems coincides with the formation of fibrous wood, hence we speculate that the latter process is also regulated by gibberellic acid.   Concluding, the wood of secondarily woody carrots is generally non-paedomorphic while its few paedomorphic traits are most likely associated with wood parenchymatization and a limited radial growth, and with the mechanical constraints imposed by the rosette tree habit.


Related Links:
Details of the project on secondary woodiness in Apioideae, Apiaceae


1 - University of Warsaw, Faculty Of Biology,, Depart. Of Molecular Phylogenetics and Evolution, University Of Warsaw Biological And Chemical Centre, Zwirki i Wigury 101, Warszawa, PL-02-089, Poland
2 - Botanical Museum, Prof Popov Str. 2, St. Petersburg, 197376, Russian Federation
3 - Jardim Botânico da Madeira, Eng. Rui Vieira Caminho do Maio, Bom Sucesso, Funchal, Madeira, 9064-512, Portugal
4 - VIA APIA, 10 rue de l'Arsenal, Mulhouse, 68100, France
5 - Jardín de Aclimatación de la Orotava (ICIA), C/Retama no. 2, Puerto de la Cruz, S/C de Tenerife, 38400, Spain
6 - University Of Warsaw, Faculty Of Biology, Dept. Of Molecular Phylogenetics And Evolution, University Of Warsaw Biological And Chemical Centre, Zwirki I Wigury 101, Warszawa, PL-02-089, Poland

Keywords:
Daucus
Monizia
Melanoselinum
Cryptotaenia
secondary woodiness
paedomorphosis
Apiaceae
Plant Anatomy.

Presentation Type: Colloquium Presentations
Number: 0008
Abstract ID:117
Candidate for Awards:Katherine Esau Award


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