Números cromossômicos e implicações sistemáticas em espécies da subfamília Caesalpinioideae (Leguminosae) ocorrentes na região sul do Brasil

Abstract

-(Chromosome numbers and systematic implications in species of subfamily Caesalpinioideae (Leguminosae) from the Southern region of Brazil). The subfamily Ceasalpinioideae (Leguminosae) comprises around 2,800 species, many of which occurring in Brazil. For the Southern region of Brazil, 56 species economically, socially and scientifically important, are cited, distributed along different environments, but detailed taxonomic and cytogenetic studies are still missing. This paper reports chromosome number analysis in 74 accessions of 27 taxa belonging to ten genera of tribes Cassieae, Caesalpinieae, and Cercideae. The determined chromosome numbers were 2n = 32, 28, 26, 24, 22, 16 and 14. For seven species the chromosome numbers were determined for the first time: Cassia leptophylla, Senna araucarietorum, S. hilariana, S. neglecta, S. oblongifolia, Chamaecrista repens and Pomaria stipularis. Most species had 2n = 28 chromosomes, 2n = 26, 24, and 22 being also found. The genus Chamaecrista differs from the others studied as all its taxa presented 2n = 32, 16, and 14, the first one derived by polyploidy. The basic number of x = 14 was proposed for the species of nine of the studied genera, while x = 13, 12 and 11 would have probably been originated by disploidy. For the genus Chamaecrista, x = 8 is suggested for most species and x = 7 for the species of section Xerocalyx. Polyploidy seems to have played an important role in the initial diversification of the group, accompanied by several disploid reductions during the evolutionary process. The number of chromosomes distinguishes Chamaecrista from the other genera. This, together with other analyzed characteristics, as well as literature data, supports the separation of this genus from the other Cassieae genera.

Karyomorphology of Caesalpinia Species (Caesalpinioideae: Fabaceae) from Caatinga and Mata Atlantica Biomes of Brazil

“…Cangiano and Bernardello (2005) reported C values of 1.90 µm in C. gilliessi, C. paraguariensis, and C. mimosifolia. Within the Caesalpinioideae, the C values reported by Auler and Battistin (1999) and Biondo et al (2005) were equal to or inferior to 2.0 µm. The haploid karyotype length obtained in our study varied from 39.86 µm in C. calycina to 24.63 µm in C. microphylla.…”

Análisis del cariotipo del híbrido natural Aloe x spinosissima y de sus parentales Aloe arborescens y Aloe humilis, mediante bandeo cromosómico C, CMA y DAPI

“…Poggio et al (1999) han señalado que los sistemáticos están familiarizados con el hecho que los cromosomas son parte de un sistema dinámico que está moldeando el proceso de la evolución. Así la citogenética ha sido empleada con fines sistemáticos y evolutivos dentro de la gran diversidad de angiospermas: en Bromeliaceae (Pires et al 2000); en el grupo Cymbidioide de las orquídeas de Brasil (Pessoa & Guerra 2000); Araceae (Sultana et al 2006), en especies brasileñas de Xyris, Xyridaceae (Benko 2002); en algunas especies de Alismataceae de Brasil (Costa & Forni-Martins 2003); en Leguminosas (Seijo & Fernández 2003;Biondo et al 2005;Fahmy 2006), Leucocoryne, Amaryllidaceae (Souza 2015), entre otros; así como para llevar a cabo la identificación de procesos de hibridización en Lilium (Lim et al 2001); en algunas especies e híbridos interespecíficos de Pennisetum, Poaceae (Techio et al 2002), entre otros.…”

Karyomorphology and karyotype asymmetry in the South American Caesalpinia species (Leguminosae and Caesalpinioideae)

“…s.l., comprises approximately 140 species with morphological characteristics that are very similar to each other (Lewis, 1998;Gasson et al, 2009). Caesalpinioideae has great interspecific and intraspecific variability in the number of chromosomes, and many species have diploid or an unknown chromosome number (Beltrão and Guerra, 1990;Jena et al, 2004;Biondo et al, 2005, Rodrigues et al, 2012. Taxonomic studies support the hypothesis that Caesalpinioideae is a non-natural group comprising paraphyletic tribes (Tucker and Douglas, 1994;Käss and Wink, 1996;Doyle et al, 1997Doyle et al, , 2000Herendeen, 2000;Bruneau et al, 2001;Kajita et al, 2001).…”

“…Cytogenetic studies are important to Caesalpinioideae studies, but they are still scarce in this subfamily (Biondo et al, 2005). Cytogenetic analysis has been used in cytotaxonomic analyses, particularly by comparing the number and morphology of chromosomes of species at different taxonomic levels.…”

“…The number and morphology of chromosomes are the distinctions that are more frequently used in cytogenetics (Biondo et al, 2005). A direct comparative analysis of cytogenetic data in closely related species allows pinpointing the unique features of each species, as well as those that are common to all or to most of them (Guerra, 1990).…”