Is there an association between chromosome number and ploidy with growth habit in the subfamily Orchidoideae (Orchidaceae Juss.)?

• Grant number: 24/02667-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2025
• End date: March 31, 2026
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Ana Paula de Moraes
• Grantee: Leticia Wanderley Cavalcanti
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 21/10639-5 - Center for Research on Biodiversity Dynamics and Climate Change, AP.CEPID

Abstract

The existence of associations between cytogenetic characteristics, such as chromosome number and ploidy, and ecological traits, such as growth habit, was proposed almost a century ago. However, such associations may be obscured by incomplete sampling or biased by phylogenetic conservatism, making it often impossible to validate whether and at which taxonomic level(s) this hypothesis can be accepted. To achieve this, analyses that integrate cytogenetic and ecological data depend on an evolutionary context that can only be provided by broad and robust phylogenetic hypotheses, combined with the use of phylogenetic comparative methods. Orchidaceae, a widely distributed family with great diversity of growth habits and variation in chromosome number, emerges as a good model for such studies. Thus, the present project aims to investigate the potential associations between chromosome number/ploidy and growth habit using the second-largest subfamily of Orchidaceae, Orchidoideae. Considering the results already obtained for Epidendroideae, conducting analyses in Orchidoideae will allow for a comparison of the two largest subfamilies of Orchidaceae in terms of the associations between cytogenetic and ecological characteristics. Therefore, this proposal aims to revisit traditional hypotheses of association between cytogenetic and ecological traits, seeking to identify general patterns that can be applied to plants based on the analysis of Orchidoideae in comparison to Epidendroideae.