Strong postzygotic isolation prevents introgression between two hybridizing Neotropical orchids, Epidendrum denticulatum and E-fulgens

Author(s)

Pinheiro, Fabio ^[1] ; Cardoso-Gustavson, Poliana ^[2] ; Suzuki, Rogerio Mamoru ^[2] ; Abrao, Monique Cristine R. ^[2] ; Guimaraes, Leonardo R. S. ^[2] ; Draper, David ^[3] ; Moraes, Ana Paula ^[4]

Affiliation

^[1] Univ Estadual Paulista UNESP, Inst Biociencias, Dept Bot, BR-13506900 Rio Claro, SP - Brazil

^[2] Nucleo Pesquisa Orquidario Estado, Inst Bot, BR-04301902 Sao Paulo, SP - Brazil

^[3] Univ Tecn Particular Loja, Dept Ciencias Nat, Loja 1101608 - Ecuador

^[4] Univ Estadual Paulista UNESP, Inst Biociencias, Dept Genet, BR-18618970 Botucatu, SP - Brazil

• Document type: Journal article
• Source: EVOLUTIONARY ECOLOGY; v. 29, n. 2, p. 229-248, MAR 2015.
• Web of Science Citations: 7

Abstract

Studies on hybrid zones are essential to understand the origin and evolution of reproductive barriers in plants. To achieve this goal, multidisciplinary approaches are often required to investigate the role of multiple reproductive isolation (RI) mechanisms. For Epidendrum denticulatum and E. fulgens, two Neotropical food-deceptive orchid species, we used molecular, cytogenetic and morphological analyses, experimental crosses and environmental envelope models to assess the strength of the RI and the mechanisms that prevent species collapse when hybridization occurs. Based on genetic assignment tests, hybrids between E. denticulatum and E. fulgens were detected. However, the low frequency of hybrid specimens found, coupled with the high morphological differentiation between parental species, suggested that strong barriers exist to interspecific gene exchange. Indeed, hybrid plants were largely sterile, as determined by meiotic data and crossing experiments. In the hybrid zone studied here, strong postzygotic barriers maintain species integrity, and these RI mechanisms may be also important during early stages of speciation. (AU)

• FAPESP's process: 09/15052-0 - Phylogeography of the species of Epidendrum (Orchidaceae) belonging to the Atlantic clade (subgenus Amphiglottium)
• Grantee: Fábio Pinheiro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 12/22077-2 - Plant genome feedback to the environmental variations: what Orchidaceae have to tell?
• Grantee: Ana Paula de Moraes
• Support Opportunities: Scholarships in Brazil - Young Researchers
• FAPESP's process: 11/22215-3 - Plant genome responses to environmental variation: what Orchidaceae have to tell?
• Grantee: Ana Paula de Moraes
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 10/16353-1 - Phylogeny and cytotaxonomy of the "clade Stenorrhynchos" (Spiranthinae, Cranichideae, Orchidoideae, Orchidaceae)
• Grantee: Leonardo Ramos Seixas Guimarães
• Support Opportunities: Scholarships in Brazil - Doctorate