Chromosome numbers and meiotic analysis in three species of Tropaeolum (Tropaeolaceae)

  • Aldo Rubén Andrada Instituto de Genética, Fundación Miguel Lillo, San Miguel de Tucumán, Tucumán, Argentina
  • Valeria de los Ángeles Páez Instituto de Genética, Fundación Miguel Lillo, San Miguel de Tucumán, Tucumán, Argentina
  • Eva Bulacio Laboratorio de Taxonomía Fanerogámica, Fundación Miguel Lillo, San Miguel de Tucumán, Tucumán, Argentina
Keywords: chromosome numbers, meiosis, pollen viability, Tropaeolum

Abstract

Tropaeolum (Tropaeolaceae) comprises approximately 100 species mainly distributed from México to South of Argentina and Chile. Fifteen species inhabit in Argentina at 700-3500 m altitude. Chromosome counts in this genus indicate a constant basic chromosome number x = 14. In this paper, three species widespread in the Northwestern of Argentina were cytogenetically studied: T. argentinum, T. atrocapillare and T. capillare. Flower buds were treated by classical cytogenetical techniques. The gametophytic chromosome number from the three species here analysed was n = x = 14. During cell division, secondary chromosomic associations and a lot of irregularities were observed such as lagging chromosomes, chromatin bridges and unbalanced segregations. Our results, which highlight the diploid character in taxa from this region, disclose the first cytological studies of these species.

Published
2019-06-30
Section
ORIGINAL ARTICLES