A NEW INSIGHT IN SERJANIA MILL. (SAPINDACEAE, PAULLINIEAE) INFRAGENERIC CLASSIFICATION: A CYTOGENETIC APPROACH

JUAN PABLO COULLERI; MARIA SILVIA FERRUCCI; MASSIMILIANO DEMATTEIS

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Lugar: Viena; Año: 2012 vol. 298 p. 1743 - 1753

0378-2697

Serjania (Sapindaceae, Paullinieae) comprises about 230 species, currently present two infrageneric classification proposals, both difficult to apply. This work test which infrageneric classification fit better in relation to cytogenetic traits added to the main morphological features used by the authors of the subgenus arrangements, and, gain an insight into the karyotype evolutionary relationship. In order to test the relationship of karyotypes and the systematic of this genus were karyotypically described five species of Serjania belonging to five different sections (sensu Radlkofer); these results were complemented with the known karyological information of 26 species. And, with these data, a cluster analyses was setup to test which infrageneric classification fit better. In addition, a principal component analysis (PCA) was performed in order to examine the relevance of the traits in the subgenus classification. All the karyotypes analyzed (both new records as the previous ones) have 2n=24 chromosomes, karyotypes are asymmetrical: submetacentrics and metacentrics chromosomes are common, whereas telocentrics ones are rare. The PCA revealed seven principal components, the first two explain the 52% of the total variation, and these last ones are related with all the karyotypic features studied. The phenogram obtained reflect a scarce fitting into both infrageneric classifications, being represented only three sections of the twelve proposed by Radlkofer and two of the six sections of Acevedo-Rodríguez. Finally, regarding to the karyotype evolution the constancy of chromosome number and the variation in the length of the complement suggest that structural chromosomes changes would have played a leading role.