Chromosomal studies of species of Rubiaceae (A. L. de Jussieu) from the Brazilian cerrado

Abstract

-The chromosomes of 14 species belonging to two subfamilies of the family Rubiaceae collected in the Brazilian cerrado were studied. In the subfamily Ixoroideae, five species (Alibertia concolor, A. edulis, A. sessilis, Genipa americana and Tocoyena formosa) had a chromosome number of 2n = 22 and one (Amaioua intermedia) showed polyploidy, with 2n = 66. All of the chromosome numbers were multiples of the more common basic number for this family (x = 11). In the subfamily Rubioideae, variations in the number of chromosomes were observed among tribes and genera, with 2n = 20 in the tribe Coccocypseleae (Coccocypselum lanceolatum), 2n = 28 in Spermacoceae (Borreria latifolia, B. verticillata and Richardia brasiliensis) and n = 11 in Coussareeae (Coussarea hydrangeifolia). In the tribe Psychotrieae, the variations included n = 11 (Palicourea rigida), 2n = 22 (Psychotria hoffmannseggiana) and 2n = 32 (Psychotria deflexa). The ideograms elaborated for 12 species were symmetrical (TF% varied from 47.45 to 38.01). The size of the chromosomes ranged from 1.26 to 7.33 µm and most were metacentric. The results show that chromosome size and morphology were insufficient to differentiate among groups within the Rubiaceae.

Chromosome count improvement and digitalization of Neolamarckia cadamba

“…It is generally accepted that the majority of species in the Rubiaceae family which N. cadamba belongs have a basic chromosome number 11 (x = 11). This basic chromosome number is still valid, in agreement with our study and many other studies in decades [1,13,21,23,26,27,28,29]. Based on the most comprehensive chromosome number data compiled in 1979; 730 species in the Rubiaceae family were examined; 493 species have chromosome base number x = 11; 200 species are polyploids at different levels of ploidy and 155 species are tetraploids with 44 chromosomes (2n = 4x = 44) [1].…”

“…Chromosomes of woody angiosperms are usually small, and there is little size difference between related species and genera [24]. However, chromosome size and morphology are of little taxonomic use in family Rubiaceae [26].…”

Phylogeny of Coussareeae (Rubioideae, Rubiaceae)

“…In this study, the color blue includes purple, and pale blue includes pale lilac. Additionally, the Kiehn (1995); k Müller Argoviensis (1881); l Costa and Mamede (2002); m Taylor et al (2004); n Kirkbride (1976); o Di Maio (1996); p Steyermark (1978); q Corrêa and Forni-Martins (2004 Smooth-rugose f Bradea -Subshrub or shrub (rarely herb) g,h 2-3 unequal lobes g,i 4-merous, funnelform, white/pale blue/pink g,i Axial on stalked/linear placenta g,h…”

Analysis of meiotic behavior in Cordia ecalyculata Vell. (Boraginaceae)

“…Irregularities related to the chromosomal segregation process, such as disoriented chromosomes, precociously migrating chromosomes, laggard chromosomes and micronuclei formation, have been reported in several different plant species, including: Psychotria carthagenensis (CORRÊA; FORNI-MARTINS, 2004), Brachiaria brizantha (MENDES-VIEIRA et al, 2006. ), Meconopsis aculeata (SINGHAL; KUMAR, 2008), Brachiaria bovonei (RISSO-PASCOTTO et al, 2009), Passilora serrato-digitata (KIIHL et al, 2011), Meliaceae species (GROSSI et al, 2011), Alchornea triplinervia (GODOY et al, 2012), and Psychotria myriantha (ALONSO-PEREIRA et al, 2013).…”

“…This species produces red fruit, similar to coffee. The fruits are appreciated by animals, and can be toasted and commercialized as a tea product (CRUZ, 1995;LORENZI, 2002). Cordia ecalyculata is also widely used for medicinal purposes, primarily by indigenous people, being indicated as a tonic, diuretic, anti-inlammatory agent and appetite inhibitor (LORENZI; MATOS, 2008).…”