Karyotype morphology and evolution in some Lathyrus (Fabaceae) species of southern Brazil

Abstract

The karyotypes of Lathyrus nervosus Lam., L. pubescens Hook. et Arn., L. paranensis Burk. and L. crassipes Gill ap. Hook et Arn., native to Rio Grande do Sul (southern Brazil), are described in detail for the first time. All taxa have 2n = 14 chromosomes. The karyotypic formulae were 2 m + 12 sm for L. nervosus, L. pubescens and L. paranensis and 4 m + 10 sm for L. crassipes. In all species, the smallest chromosome pair bore a secondary constriction with a satellite in the long arm. Intraspecific variability in the position and number of secondary constrictions was observed in L. nervosus and L. pubescens. All of the species had a conservative and similar karyotype morphology, but differed in total complement size by as much as 20% between the highest (L. nervosus) and lowest (L. crassipes) values. These results suggest that changes in chromosome size during evolution have been similar for all the chromosomes of the complement. Together with data on the life cycle and mode of reproduction, these results also indicate that L. crassipes is a derived taxon, if an evolutionary trend towards a decrease in chromosome size is accepted.

Structural karyotypic variability and polyploidy in natural populations of the South American Lathyrus nervosus Lam. (Fabaceae)

“…Both species grow in Eurasia and are included in sections Orobus and Pratensis, respectively. Concerning the South American species, the cytological data available also revealed high constancy of the diploid chromosome number 2n = 14 among all the taxa analysed (Battistin and Fernández 1994;Klamt and Schifino-Wittmann 2000;Seijo and Fernández 2003).…”

“…Concerning the karyotype formula, some authors claim that Lathyrus species show a strong morphological uniformity of chromosomes and a homogeneous karyotype arrangement (Narayan and Durrant 1983;Klamt and Schifino-Wittmann 2000;Badr 2007). By contrast, other authors have found enough interspecific karyotype differences to allow species characterization (Yamamoto et al 1984;Murray et al 1992;Battistin and Fernández 1994;Seijo and Fernández 2003).…”

The cytogenetics and evolution of forage legumes from Rio Grande do Sul: a review

“…The karyotypes of 38 accessions of L. nervosus, L. pubescens, L. paranensis and L. crassipes have been analyzed (Klamt, 1997;Klamt and Schifino-Wittmann, 2000), the karyotypic formulae being 2 m + l2 sm for L. nervosus, L. pubescens and L. paranensis and 4 m + 10 sm for L. crassipes. In all these species the smallest chromosome pair bore a secondary constriction with a satellite in the long arm.…”

Morphological, anatomical and karyological investigations of the Turkish endemic species Lathyrus woronowii Bornm. (Fabaceae)

“…Some karyology studies were previously conducted within this genus, including the studies of Senn (1938), Ress and Hazarika (1969), Fouzdar and Tandon (1975), Yamamoto and Fujiwara (1984), Kuriyan and Narayan (1988), Kumar and Sinha (1989), Kakoli and Sumitra (1991), Şahin and Babaç (1995), Şahin et al (2000), Klamt and Schifino-Wittmann (2000), Seijo and Fernandez (2003), Ertekin (2008), andGüneş (2011b). These studies indicated that the genus Lathyrus generally has a diploid chromosome number of 2n = 14, as reported in approximately 95 Lathyrus species worldwide.…”