Exploring local morphological and molecular variation in parasitic species Gaiadendron punctatum (Loranthaceae) from Northwestern Andes of Colombia

ABSTRACT

Gaiadendron punctatum (Ruiz & Pav.) G. Don. exhibits a wide morphological variation and geographical distribution, ranging from Nicaragua to Bolivia. Reported polymorphism and the existence of more than 20 synonyms for Gaiadendron punctatum might indicate that there is either a cryptic complex, or that this species shows great variation. Populations from Northwestern Colombia were sampled to evaluate if local morphological variation was reflected in molecular variation. Two chloroplast regions were used, and haplotype networks were performed for each region. Also, reproductive and vegetative characters were compared between populations. Three different morphotypes were observed according to examined variables. DNA sequences showed some nucleotide substitutions and indels that characterized some of the morphotypes. Network analyses group together individuals of the same morphotype for both regions. We found evidence that the three different morphotypes here described showed some degree of genetic identity. Further work is needed for sampling along the whole distribution range of this species, to propose hypotheses about different entities or the existence of a single polymorphic taxon with altitudinal ecotypes.

Gaiadendron punctatum (Ruiz & Pav.) G. Don. exhibe una amplia variación morfológica y distribución geográfica, desde Nicaragua hasta Bolivia. El polimorfismo reportado y la existencia de más de 20 sinónimos para Gaiadendron punctatum podría indicar que existe un complejo críptico o que esta especie muestra una gran variación. Se muestrearon poblaciones del Noroccidente de Colombia para evaluar si la variación morfológica local se reflejaba en variación molecular. Se usaron dos regiones cloroplastídicas y se realizaron redes de haplotipos para cada región, también se compararon caracteres vegetativos y reproductivos entre poblaciones. Se observaron tres morfotipos diferentes de acuerdo con las variables examinadas. Las secuencias de ADN mostraron algunas sustituciones nucleotídicas, así como indels que caracterizaron algunos de los morfotipos. El análisis de redes agrupa individuos del mismo morfotipo para ambas regiones. Se encontró evidencia de que los tres morfotipos diferentes aquí descritos mostraron algún grado de identidad genética. Más trabajos se requieren, muestreando a través del rango completo de distribución de esta especie para proponer hipótesis sobre diferentes entidades o la existencia de un solo taxón polimórfico con ecotipos altitudinales.

KEYWORDS:

• Ecotypes
• haplotypes
• polymorphism
• species complex
• Santalales

Acknowledgments

We thank Francisco Javier Roldán, Mailyn González, Herber Sarrazola and Jhon Steven Murillo for their taxonomic help and suggestions. We also thank the staff at herbaria COAH, COL, FAUC, HUA, JAUM and MEDEL for granting access to study their Gaiadendron specimens. Authors thank two anonymous reviewers for their comments to improve previous versions of the manuscript.

Disclosure statement

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

Author contributions

F. Alzate-Guarín, I. Carmona-Gallego, and R. Vidal-Russell designed the study, I. Carmona-Gallego and F. Alzate-Guarín collected data and generated the sequences; I. Carmona-Gallego, F. Alzate-Guarín and R. Vidal-Russell analyzed the data and wrote the manuscript.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt and the Grupo de Estudios Botánicos.