Karyotype with 210 chromosomes in guarana (Paullinia cupana 'Sorbilis')
2007
de Freitas, D.V.(Universidade Federal do Amazonas, Manaus (Brazil)) | Carvalho, C.R. | Filho, F.J.N. | Astolfi-Filho, S.
The genus Paullinia includes the economically important P. cupana, known as guarana in Brazil and more recently in the world market. Native Americans of the Maue and Andira tribes cultivated P. cupana 'Sorbilis' in central Amazon, and the Bares cultivated the 'Typica' variety in the upper Negro River (Brazil). Cytological studies in the Sapindaceae family have concentrated on the diversity in number (from 2n = 14 to 96) and size of the chromosomes. In Paullinia, seven species have been karyotyped and all show 2n = 24. Meristem maceration, cellular dissociation and air-drying techniques were used for cytogenetic preparations and DNA content was determined by flow cytometry. Chromosome characterization and DNA content of Paullinia cupana Kunth 'Sorbilis' (Mart.) Ducke (Sapindaceae) were studied. The high chromosome number (2n = 210) fall into two cytomorphological groups: (a) a metacentric and submetacentric group showing 25 sets of three pairs of chromosomes (2-76); (b) a group containing only acrocentric showing 12 sets of two pairs of chromosomes (82-105), a homologous submetacentric pair (1) and an acrocentric pair (81). Mean nuclear DNA content of guarana was 2C = 22.8 pg. A karyogram was set up showing a high chromosome number complement.
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