Heterochromatin and rDNA patterns in Solanum species of the Morelloid and Dulcamaroid clades (Solanaceae)

MOYETTA, N.; URDAMPILLETA, J.; CHIARINI, F.; BERNARDELLO, G.

PLANT BIOSYSTEMS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2016

1126-3504

The heterochromatin distribution and the position of 18-5.8-26S and 5S rDNA loci were determined in 13 species of Solanum of the Morelloid and Dulcamaroid clades. The CMA/DAPI staining and FISH was employed. Two types of constitutive heterochromatin were determined: CMA+/DAPI- associated to NOR and CMA+/DAPI- distributed as terminal bands. In the Morelloid clade, CMA+/DAPI- bands were found in five species, while in the Dulcamaroid clade, only S. angustifidum presented this feature. In the Morelloid clade, from 2 to 4 18-5.8-26S rDNA loci occupied terminal positions, and 2 rDNA 5S loci were found with variable positions (terminal, intercalary and centromeric). In the Dulcamaroid clade, were detected 2 terminal 18-5.8-26S rDNA loci, with the exception of S. salicifolium which possessed 4 such loci, and 2 to 4 5S rDNA loci. Solanum crispum is the only species possessing the 5S in synteny with 18-5.8-26S rDNA loci. Karyotype features, chromosome banding pattern as well as the location of ribosomal genes varied among the species, reflecting the chromosome differentiation and evolutionary divergence. The findings obtained contributed to the development of tools that can be used in the establishment of chromosomic homeologies among the species and clarify their taxonomic relationships.