First karyological report in Larnax and Deprea (Solanaceae)

Abstract

Somatic chromosomes of 12 samples belonging to seven Larnax Miers species and three Deprea Raf. species are studied. Chromosome number and karyotype analysis of both genera are reported for the first time. All taxa have 2n = 24. The most frequent haploid karyotype formula (8 of 12 samples) is 9 metacentric (m) + 3 submetacentric (sm) chromosomes, whereas L. glabra (Standl.) N.W. Sawyer and Larnax sp. display 10m+ 2 sm. Karyotypes of L. nieva S. Leiva & N.W. Sawyer and D. cuyacensis (N.W. Sawyer & S. Leiva) S. Leiva & Lezama are remarkable for thehighest number of sm chromosome pairs, with 7m+ 5 sm and 5m+ 7 sm, respectively, presenting the highest intrachromosomal asymmetry index (A1), whereas Larnax sp. and L. glabra show the lowest A1. Most samples (9 of 12) examined have only one pair of chromosomes with nucleolar organiser regions (NOR), whereas L. glabra, Larnax sp., and D. cuyacensis possess two pairs of NOR. Systematic considerations about the monophyly of Larnax and Deprea are provided. The different karyotype parameters obtained, together with morphological characters, are discussed to single out the species.