Karyotype and nuclear DNA content of Psychotria ipecacuanha: a medicinal species

Abstract

Summary Psychotria ipecacuanha, ipecac, is a perennial, medicinal herb that grows in clusters in the understory of humid and shady areas of the Brazilian Atlantic and Amazon forests. Cytogenetic studies performed in this species have reported 2nϭ22 chromosomes, with limited karyotypic information. The present study was conducted in order to apply cytogenetic and flow cytometric tools in samples of ten ipecac populations, five from the Atlantic and five from the Amazon forest, with the purpose of characterizing their karyotype and measuring their 2C DNA content. The flow cytometry analyses evidenced two groups with distinct DNA amounts: MOZ population with 2Cϭ1.24 pg and GUA, TVI, TLM, VRB, RAP, MAN, RVE, BBU and PRA populations with 2Cϭ2.05 pg. Metaphasic chromosomes obtained from root apical meristems of GUA, TLM and TVI showed a karyotype consisting of 11 chromosome pairs, 4 metacentric (4, 5, 8 and 9) and 7 submetacentric (1, 2, 3, 6, 7, 10 and 11), with lengths varying from 3.97 to 2.53 mm. The secondary constriction was identified in the long arm of chromosome 6. Cytogenetic characterization also reveled that each chromosome pair 2-3; 4-5; 6-7; 8-9 and 10-11 is cytogenetically similar, with regard to total length, short and long arm size, and chromosomic class, suggesting that this species might be a tetraploid plant.

Cytogenetic and identification of the nucleolus organizer region in Heliconia bihai (L.) L.

“…Identical results, regarded to the quality of mitotic metaphase, were obtained with Solanum esculentum (Karsburg et al, 2009), Capsicum annuum (L.) (Abreu et al, 2008), Jatropha curcas (L.) , Psychotria ipecacuanha [(Brot.) Stoves] (Rossi et al, 2008) and Carica papaya L. (Araújo et al, 2010). Thus, this method provides more appropriate preparations of chromosomes compared to those generated by the crushing method (Carvalho & Saraiva, 1993).…”

“…One of the advances related with the preparation of these studies is the use of antimitotic agents, or inhibitors such as amiprofos-methyl (APM) herbicides, 8-hidroxyquilonein, trifluralin and oryzalin that block cell cycles in specific phases of mitosis (Sumner, 1990;Singh, 1993;Rossi et al, 2008).…”

“…The blocking agents, such as APM, are essential for studying the chromosomes, for preventing the formation of the spindle and accumulating sufficient number of metaphase for a proper morphometric analysis, enabling the classification and identification of homologous pairs (Singh, 1993;Araújo, 2008;Rossi et al, 2008;Karsburg et al, 2009). Using APM also results in elongated chromosomes, with adequate compression for cytogenetic analysis (Planchais et al, 2000).…”

“…The use of fixative solutions also prevents the action of endonucleases, which permits detailed characterization of the karyotype of the species under study (Sumner 1990;Sybenga, 1992), as well as increases basophilia of the chromosomes, facilitating their coloration (Sharma & Sharma, 1999cited by Araújo, 2008. Moreover, the techniques of enzymatic maceration, cell dissociation and air drying enable obtaining slides with prometaphase and metaphase chromosomes, spread with no overlaps and in the same focal plane (Carvalho, 1995;Araújo, 2008;Rossi et al, 2008;Karsburg et al, 2009).…”

Morphoanatomy of Shoot-Bud Forming Root Systems of Poaia (Carapichea ipecacuanha(Brot.) L. Andersson) - Rubiaceae

“…Atualmente, encontra-se ameaçada de erosão genética e na lista vermelha de espécie em vias de extinção em consequência da coleta de suas raízes e, pela drástica redução de seu habitat em áreas de subosques de florestas (Oliveira et al, 2010). Os indivíduos crescem em agregados formando reboleiras (Rossi et al, 2008), originadas pelo crescimento vegetativo da planta via raízes gemíferas, estacas caulinares ou pela germinação de suas sementes (Oliveira et al, 2010). O cultivo da espécie é dificultado por seu lento crescimento, pela baixa porcentagem de produção e germinação de sementes e, ainda, pela perda de viabilidade das sementes após estocagem (Oliveira e Martins 1998).…”