Molecular cytogenetics of Dictyoloma vandellianum A. Juss. and the ancestral karyotype of Rutaceae

Author(s)

Amanda Santos ^[1] ; Ana Emília Barros e Silva ^[2] ; Milton Groppo ^[3] ; Marcelo Guerra ^[4]

Affiliation

^[1] Universidade Federal de Pernambuco. Centro de Biociências. Departamento de Botânica - Brasil

^[2] Universidade Federal da Paraíba. Centro de Ciências Agrárias. Departamento de Biociências - Brasil

^[3] Universidade de São Paulo. Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto. Departamento de Biologia - Brasil

^[4] Universidade Federal de Pernambuco. Centro de Biociências. Departamento de Botânica - Brasil

• Document type: Journal article
• Source: Acta Botanica Brasilica; v. 35, n. 4, p. 582-588, 2022-02-04.

Abstract

ABSTRACT Determination of the chromosome base number of a taxon is fundamental to understanding karyotypic variation and its implications for the evolution of that group. This usually requires careful evaluation of cytological literature and robust phylogenetic support. The base number for the family Rutaceae (x = 9 or x = 18) has long been the subject of debate. Here, we analyzed the banding pattern, rDNA sites, and genome size of Dictyoloma vandellianum, subfamily Cneoroideae, the sister group of the remaining Rutaceae, and revised critical points about the chromosome base number of the family. We found that this species has n = 9, which differs from the n = 18 possessed by other cytologically known Cneoroideae species. Thus, n = 9 occurs in the main clades of Rutaceae and is the most probable base number of the family. The hypothesis of x = 18 as the base number is no longer sustainable, although n = 18 is very common in Rutaceae. Moreover, the fluorescent banding pattern and the relatively large genome size (1C = 1.3 pg) of D. vandellianum suggest that its chromosomal organization is highly divergent from Aurantieae, the only large Rutaceae clade where species with n = 9 are greatly dominant. (AU)

• FAPESP's process: 16/06260-2 - Integrative systematic studies in Neotropical families, with emphasis on Rutaceae, Asteraceae and Rubiaceae
• Grantee: Milton Groppo Júnior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 07/06336-0 - Phylogenetic and systematic studies in Rutaceae: cladistic analysis and position of Almeidea A.St.-Hil. within Galipeinae (Galipeae, Rutoideae) inferred from morphological and molecular data.
• Grantee: Carla Poleselli Bruniera
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 06/03170-0 - Phylogenetic and systematic studies in Rutaceae: phylogeny and delimitation of Galipeinae (Galipeae) based on nuclear and plastidial DNA sequences
• Grantee: Milton Groppo Júnior
• Support Opportunities: Research Grants - Young Investigators Grants