Genome size evolution in Sapindaceae at subfamily level: a case study of independence in relation to karyological and palynological traits.

COULLERI, J. P.; URDAMPILLETA, J. D.; FERRUCCI, M. S.

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2014 vol. 174 p. 589 - 600

0024-4074

Sapindaceae s.l. is a moderately large family of trees, shrubs, and lianas. Current knowledge on genome size and how it varies in this family is scarce. This research aims at characterizing DNA content in 39 species of Sapindaceae, mainly in the Paullinieae s.s. tribe, by analysing the variation in genome size relative to karyotypical and palynological features. Nuclear DNA amount was measured by flow cytometry, and linear regression analyses were conducted to analyse the relationship between genome size variation and various karyotypic and palynological features. Genome size varied 9-fold among species, ranging from 1C = 0.305 pg (Lophostigma plumosum) to 2.71 pg (Cardiospermum heringeri). The low regression coefficients obtained suggest that genome size mainly varies independently of karyotypic and palynological features. Regarding karyotype evolution, constant chromosome number, but variable genome size in Houssayanthus, Paullinia and Serjania suggest that structural changes are more important than numerical change. By contrast, in Cardiospermum and Urvillea, variation in both chromosome number and genome size supports the suggestion that both numerical and structural changes are important in the karyotype evolution of these genera.