Further cytogenetical studies on diploid and polyploid species of Eryngium L. (Saniculoideae, Apiaceae) from Argentina

Abstract

Meiotic studies are carried out in 7 species of Eryngium L. (Saniculoideae, Apiaceae), belonging to both sections Foetida and Panniculata. The chromosome number of E. dorae Norm. (n=8) (Foetida) is reported for the first time, while the gametic chromosome number of E. nudicaule Lam. (n=7) (Foetida) and E. eburneum Decne. (n=8), E. horridum Malme (n=8), E. megapotamicum Malme (n=16), E. mesopotamicum Pedersen (n=24), and E. pandanifolium Cham. et Schlechtd. (n=24) (all belonging to Panniculata) is confirmed in several natural populations. Whereas in section Foetida all species are diploids and two basic chromosome numbers are present (x=8 and x=7), in section Panniculata all species are x=8 but there are three different ploidy levels (diploid, tetraploid, hexaploid). This study reveals that meiosis in all species is normal, with regular bivalent formation in all studied cells. Furthermore, the pollen stainability is above 80% in all cases. These data, together with the previous karyotype analyses, will contribute to the clarification of the relationships between members of both sections, where different mechanisms of speciation have been postulated.

Cytogenetic characterization of Aloysia virgata Ruiz and Pavan (Verbenaceae)

“…If A. virgata has tetraploid origin, the meiotic success observed here could be explained by genic control of the pairing of distinct genomes in an alotetraploid or a high degree of homology between the genomes (Riley and Chapman, 1958;Sybenga, 1996;Dagne, 2001). A regular meiotic behavior may also be indicative of polyploidy established by diploid-like behavior at meiosis (De Wet, 1979;Widen and Widen, 2000;Ozkan et al, 2001;O´Leary et al, 2004). An additional hypothesis is that natural selection may have eliminated the eventual problems caused by chromosomes with a normal meiotic behavior.…”

Species boundaries within the recently diverged South American monocot‐like Eryngium (Apiaceae, Saniculoideae) based on biogeographic, climatic, morphological, and molecular data: E. cerradense, a new species from Paraguay

“…These plants resemble monocotyledons in leaf morphology and plant architecture, as they possess a rosette of sessile, generally linear or subulate and parallel‐veined leaves and a well‐developed cauline axis, erect and with several internodes (Calviño & al., 2008). Many monocot‐like Eryngium are polyploids and different ploidy levels may occur within a species (Bell & Constance, 1960, 1966; Constance & al., 1971, 1976; O'Leary & al., 2004; Perthuy & al., 2010). To date, molecular phylogenies are inconclusive as to the monophyly of this striking group (Calviño & al., 2008, 2010), comprising at least two different clades (i.e., South American monocot‐like and North American monocot‐like clades) that are part of a polytomy together with additional South American monocot‐like species, and other Eryngium clades (e.g., Pacific clade; Calviño & al., 2008, 2010).…”

Molecular and ecological study of Eryngium species in Syria

“…Many studies have been carried out to investigate the genus Eryngium L. (Apiaceae-subfamily Saniculoideae) (O'Leary et al 2004;Wörz 2004;Clausing et al 2000;Gaudeul et al 2000). The genus includes about 250 species in Eurasia, North Africa, North and South America and Australia (Pimenov & Leonov 1993;reviewed in Wörz 2004).…”