Karyotype analysis for diploid and polyploid species of the Solanum L.

Abstract

Solanum species were cytogenetically analysed to localize species-specific markers. Solanum atropurpureum Schrank, S. dulcamara L., S. gilo Raddi., S. melongena L., S.nitidibaccatum Bitter and S. paniculatum L. showed 2n = 24, whereas S. luteum Mill., S.nigrum L. and S. laciniatum Ait. showed 2n = 48, 2n = 72 and 2n = 92, respectively. All species demonstrated a symmetrical karyotype. The average chromosome size varied between diploid (1.95 μm) and polyploid (1.31 μm) species. Application of the CMA3/DAPI technique showed two CMA3+/DAPI− terminal blocks in S. dulcamara, S. atropurpureum and S. luteum, indicating one homologous pair. In S. nitidibaccatum two large CMA3+/DAPI− segments were observed apart from several terminal blocks in almost all chromosomes. The same CMA3+ telomeric standard was also found in prometaphases of S. luteum. Similar results were obtained with FISH with 45S rDNA probes: fluorochrome CMA3+ telomeric blocks associated with satellites, with two blocks in S. atropurpureum, S. dulcamara, S. nitidibaccatum and S. luteum and four blocks in S. nigrum and S. lacinatum. Localization of species-specific markers was successful, allowing recognition of particular cytological features in most of the species analysed.