Genome size and climate segregation suggest distinct colonization histories of an orchid species from Neotropical high-elevation rocky complexes

Autor(es)

Lopes Gomes, Shaiany Sabrina ^[1] ; Vidal, Joao D. ^[2] ; Neves, Camila Siqueira ^[1] ; Zorzatto, Cristiane ^[1] ; Silva Campacci, Thiago Vinicius ^[3] ; Lima, Amanda Kassia ^[1] ; Koehler, Samantha ^[3] ; Viccini, Lyderson Facio ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Juiz De Fora, Inst Ciencias Biol, Dept Biol, Lab Genet, BR-36036900 Juiz De Fora, MG - Brazil

^[2] Univ Estadual Paulista, Inst Biociencias Botucatu, Programa Posgrad Bot, BR-18618689 Botucatu, SP - Brazil

^[3] Univ Estadual Campinas, Inst Biol, Dept Biol Vegetal, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Biological Journal of the Linnean Society; v. 124, n. 3, p. 456-465, JUL 2018.
• Citações Web of Science: 1

Resumo

Knowledge about the geographical distribution of cytotypes is crucial to understand the role of polyploidy in diversification. High-elevation rocky complexes (HERCs) are heterogeneous formations found in elevated areas of eastern Brazil. They harbour one of the most endemic floras within the Neotropical region. Yet, we lack knowledge concerning the association of environmental variables and plant cytotypes in this region. Here, we investigate whether the frequency of Zygopetalum mackayi orchid cytotypes is related to climate conditions in the HERCs. We describe chromosome counts, genome size estimates and their association with climate variables for 432 individuals from 19 localities. We show, for the first time, a strong association between climate variation and cytotype variation in a species from the HERCs. We confirm two cytotypes for Z. mackayi (2n = 48 and 2n = 96), which are geographically structured, and describe an intermediate cytotype (2n = 72) restricted to a contact zone. We discuss the implications of our results for chromosome evolution in this species and provide hypotheses for the origin and maintenance of cytotypes. (AU)

• Processo FAPESP: 14/04426-5 - Desvendando o papel da apomixia na diversificação das orquídeas do complexo Zygopetalum maculatum
• Beneficiário: Samantha Koehler
• Linha de fomento: Auxílio à Pesquisa - Regular