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Phylogeny of Chamaecrista Moench (LeguminosaeCaesalpinioideae) based on nuclear and chloroplast DNA regions
Author(s) -
de Souza Conceição Adilva,
Paganucci de Queiroz Luciano,
Lewis Gwilym Peter,
Gomes de Andrade Maria José,
Machado de Almeida Paulo Ricardo,
Schnadelbach Alessandra Selbach,
Berg Cássio van den
Publication year - 2009
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.1002/tax.584010
Subject(s) - biology , paraphyly , monophyly , caesalpinioideae , genus , botany , clade , pantropical , zoology , phylogenetics , fabaceae , gene , biochemistry
Abstract Chamaecrista Moench is a genus of caesalpinioid legumes with about 330 species mostly from the New World. The phylogeny of the genus was studied using sequence data from nuclear ITS and plastid trnLF DNA spacers, representing all six sections of Chamaecrista . Separate and combined analyses recovered the same major clades with high bootstrap and posterior probabilities support, except for the subclades of representatives of sections Caliciopsis, Chamaecrista , and Xerocalyx . The monophyly of Chamaecrista was highly supported in all analyses. Sections Apoucouita and Xerocalyx were supported as monophyletic, sect. Absus was paraphyletic and subsect. Baseophyllum was resolved more closely related to species of sections Chamaecrista , Caliciopsis , and Xerocalyx than to subsect. Absus . The monotypic section Grimaldia was embedded within subsect. Absus . Section Chamaecrista was paraphyletic with respect to sections Caliciopsis and Xerocalyx . Our analyses suggest that the diversification patterns in Chamaecrista occurred through an initial shift from rainforest trees to a more diverse clade of savannah shrubs. Within the latter group, two main subclades were recovered: (1) a planaltine and highmountain clade characterized by absence of extrafloral nectaries and the appearance of sticky glandular hairs; and (2) a mostly herbaceous clade with axillary fascicled inflorescences and reduced chromosome numbers. This last group is more diverse in open grassland areas and includes many colonizers of waste ground.