Eduardo A. Moscone

Karyotype analysis in several South American species of Solanum and Lycianthes rantonnei (Solanaceae)

Somatic chromosomes of 17 species belonging to 4 subgenera and 7 sections of Solanum and Lycianthes rantonnei are studied. All taxa have 2n = 24. The chromosome numbers of S. tripartitum, S. tenuispinum, and S. vaillantiiare reported for the first time, and the karyotype analysis of L. rantonnei is the first one for the genus. Morphometric chromosome analyses bring estimates of karyotype composition and asymmetry. In general, karyotypes are symmetrical with the chromosomes smaller than 4 μm long, being metacentric (69%), sub-metacentric (24%), or more rarely subtelocentric (7%). Solanum tucumanense, S. palinacanthum, and Solanum sp. (Acanthophora) are unique by having mostly sm and st chromosomes. All species have nucleolar organizing regions and attached satellites of variable size on short arms of one chromosome pair, usually sm or st. All species can be cytologically distinguished. Karyotype data do not allow separation of L. rantonnei from species of Solanum. Results support the validity of S. tucumanense with respect to S. pseudocapsicum. Using chromosome data exclusively, cluster analysis in 10 species from Solanum subgen. Leptostemonum reinforce the systematic arrangement of taxa in subsections based on morphological features. Because of its increased karyotype asymmetry, section Acanthophora appears to be an advanced taxon within subgen. Leptostemonum.

Phylogeny and Character Evolution in Nierembergia (Solanaceae): Molecular, Morphological, and Cytogenetic Evidence

Abstract Nierembergia (Solanaceae) contains 21 species found primarily in South America, with one species occurring disjunctly in Mexico. Among other features, a pollination system not found elsewhere in the Solanaceae typifies this genus. In most species, nectaries are absent, but oil-producing elaiophores are present on the corolla limb and these attract oil-collecting bees. Molecular phylogenetic hypotheses based on nuclear ITS and chloroplast rpl16 intron data support the monophyly of Nierembergia, which is sister to a clade composed of Bouchetia plus Hunzikeria. The data reconstruct two clades within the genus: one composed primarily of herbaceous species with broad stigmas and the second containing woody species with crescent-shaped stigmas. Morphological homoplasy is frequent among the species of the herbaceous clade, while the woody clade is morphologically cohesive. Chromosome counts are confirmed and karyotype features are given for 13 Nierembergia species (including six varieties) and for Bouchetia anomala, Leptoglossis linifolia, and Petunia axillaris. The two clades are also supported by karyotypic features: one has asymmetrical karyotypes, small chromosomes, and two chromosome pairs with nucleolar organizing regions (NOR) and the other has symmetrical karyotypes, large chromosomes, and only one NOR.

Karyotype analyses in three Patagonian and S. Andean endemic genera ofNicotianeae (Solanaceae)

The somatic chromosomes and karyotypes of threeNicotianeae have been studied for the first time. All of them have 2n = 2x = 22 and symmetrical karyotypes.Benthamiella pycnophylloides has 9 m pairs + 1 sm pair + 1 st pair; pairs 2, 4, 5, and 11 bear microsatellites.Combera paradoxa andPantacantha ameghinoi have 9 m pairs + 2 sm pairs; pair 11 ofC. paradoxa is satellited, while pair 9 ofP. ameghinoi bears microsatellites and shows a pericentric inversion in heterozygous state in 20% of the seedlings. Results are compared with previous chromosome reports for the tribe. The cytological data support their present position in the family system. Besides,Benthamiella, Combera andPantacantha appear to be primitive genera ofNicotianeae, a comparatively advanced tribe within the family.

New Endemic Species of Capsicum (Solanaceae) from the Brazilian Caatinga: Comparison with the Re-Circumscribed C. parvifolium

Abstract Two new species of Capsicum from the Caatinga Biome (Brazil) are described and illustrated. The two species are endemic to the north-eastern states of Brazil ( C. caatingae : Bahia, Pernambuco, and north of Minas Gerais; C. longidentatum : center of Bahia and Pernambuco) and are morphologically similar to another caatinga species, C. parvifolium. Lectotypification and a complete description for C. parvifolium, which has been confused in the literature and herbaria, are also provided. The karyotype for the three species (2n = 2x = 24) is analyzed and discussed, and a key to differentiate the endemic Capsicum species from Brazil is included.

CHROMOSOME REPORTS IN SOUTH AMERICAN NICOTIANEAE (SOLANACEAE), WITH PARTICULAR REFERENCE TO NIEREMBERGIA1,2

Abstract Chromosome counts and karyotype information from 41 populations of 20 species and 6 varieties of Nicotianeae (Solanaceae) from South America belonging to Bouchetia Dunal (x  =  8), Fabiana Ruiz & Pav. (x  =  9), Leptoglossis Benth. (x  =  10), Nierembergia Ruiz & Pav. (x  =  8, 9), and Petunia Juss. (x  =  7, 9) are given, including first reports from 14 taxa: F. densa Rémy, N. ericoides Miers, and P. patagonica (Speg.) Millán, with 2n  =  2x  =  18, and N. browallioides Griseb., N. calycina Hook., N. graveolens A. St.-Hil., N. linariifolia Graham var. glabriuscula (Dunal) A. A. Cocucci & Hunz., var. pampeana (Millán) A. A. Cocucci & Hunz., and var. pinifolioides (Millán) A. A. Cocucci & Hunz., N. pulchella Miers var. pulchella and var. macrocalyx (Millán) A. A. Cocucci & Hunz., N. rivularis Miers, N. tucumanensis Millán, and N. veitchii Hook., with 2n  =  2x  =  16. All species studied are diploids, and most have 2n  =  16. In addition, infraspecific polyploidy is recorded for the first time in N. rigida Miers (2n  =  4x  =  32) and confirmed in N. aristata D. Don (n  =  3x  =  24, 2n  =  6x  =  48). In general, karyotypes of the examined species are symmetrical and composed of comparatively small and uniformly sized chromosomes, mostly of the metacentric (m) type except in L. linifolia (Miers) Griseb., P. axillaris (Lam.) Britton, Stern & Poggenb., and P. patagonica, where submetacentric (sm) chromosomes are predominant. There are one or, rarely, two chromosomes bearing nucleolar organizing regions per basic complement. In Nierembergia, karyotype data reflect species grouping. Results suggest that Bouchetia is the closest taxon to Nierembergia, while Leptoglossis, Petunia, and Fabiana appear more distant. Possible chromosome number evolution in the tribe is speculated based on molecular phylogenetic studies by other authors. In Nierembergia, x  =  9 is proposed to be derived from x  =  8. Dysploid changes in chromosome number and conservation of chromosome morphology in the karyotypes appear as important evolutionary events in the tribe, while polyploidy is noteworthy only in Nicotiana L.

FISH and AgNor mapping of the 45S and 5S rRNA genes in wild and cultivated species of Capsicum (Solananceae)

Chromosome number and position of rDNA were studied in 12 wild and cultivated species of the genus Capsicum with chromosome numbers x = 12 and x = 13 (22 samples). For the first time in these species, the 5S and 45S rRNA loci were localized and physically mapped using two-color fluorescence in situ hybridization and AgNOR banding. We focused on the comparison of the results obtained with both methods with the aim of accurately revealing the real functional rRNA genes. The analyzes were based on a previous work that reported that the 18S-5.8S-25S loci mostly coincide with GC-rich heterochromatic regions and likely have given rise to satellite DNAs, which are not active genes. These data show the variability of rDNA within karyotypes of the genus Capsicum, providing anchor points for (comparative) genetic maps. In addition, the obtained information might be useful for studies on evolution of repetitive DNA.

Characterization of eight species of Aloe (Asphodelaceae) from the nucleolar organizing region

Fil: Sanchez, Ysbelia. Universidad Nacional Experimental del Tachira; Venezuela. Universidad Pedagogica Experimental Libertador, Institute Pedagogico de Caracas; Venezuela

The karyotype ofLimnobium spongia (Hydrocharitaceae)

The somatic chromosomes ofLimnobium spongia have been studied for the first time. Its number is 2n = 24; the karyotype is composed of 5 m pairs + 3 sm pairs + 4 st pairs. Pairs 3 and 11 bear microsatellites. Results are compared with previous chromosome reports for the family, mainly as regards the taxonomic status ofLimnobium versusHydromystria; our findings seem to support the point of view of those who favour the independence of both generic entities.