Anatomy and growth of the epiphytic cactus Epiphyllum phyllanthus under different radiation conditions

ABSTRACT

Background

Plants develop mechanisms that confer tolerance to sun or shade exposure and the knowledge of their responses may help to devise strategies for the conservation of natural populations and their propagation.

Aims

We study the effect of shading on the ecophysiology and anatomy of Epiphyllum phyllanthus to determine its plasticity and tolerance.

Methods

Specimens of E. phyllanthus were subjected to full sun, 35%, 75%, and 85% shading for 60 days. The growth characteristics, phylloclade anatomy and water content in the plants were quantified and compared. 

Results

All individuals subjected to full sun and 35% shading had died. A shading of 85% produced the highest fresh and dry mass of the stems. Higher shading caused no effect in the allocation of biomass to stems or roots or on the relative growth rate, net assimilation rate, leaf area ratio or water content. The thickness of the phylloclade increased with increased shading. The highest stomatal density on both surfaces was observed in the treatment with 75% shading. 

Conclusion

E. phyllanthus is a sciophytic plant that requires shade to survive. Its main strategy appears to be the greater accumulation of water in its phylloclade under more shaded conditions, which stimulates plant growth.

KEYWORDS:

• Cacti
• ornamental epiphytes
• plant anatomy
• sciophytes
• shading

Acknowledgements

The authors thank CNPq [Conselho Nacional de Desenvolvimento Científico e Tecnológico], CAPES [Coordenação de Aperfeiçoamento de Pessoal de Nível Superior], and FAPEMIG [Fundação de Amparo à Pesquisa do estado de Minas Gerais] for funding and research grants awarded to complete the present study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/17550874.2022.2078245.

Additional information

Notes on contributors

Maria P. B. Chaves

Maria Paula Bandoni Chaves is an undergraduate student with an interest in plant ecology and ecophysiology.

Bianca A. B. Silva

Bianca Aparecida Borges e Silva is an undergraduate student with an interest in plant ecology.

Heloisa F. Silvério

Heloisa Fernanda Silvério is an undergraduate student with an interest in ecology and biological diversity.

Flavio N. Ramos

Flavio Nunes Ramos is a professor with a research interest in plant ecology and diversity.

Vinícius P. Duarte

Vinícius Politi Duarte is a researcher who studies plant physiology and anatomy.

Evaristo M. Castro

Evaristo Mauro de Castro is a professor with research interest in plant anatomy.

Fabricio J. Pereira

Maria Paula Bandoni Chaves is an undergraduate student with an interest in plant ecology and ecophysiology.

Fabricio José Pereira is a professor with research interest in plant physiology and anatomy.