Cytomolecular characterization of cultivars and landraces of wheat tolerant and sensitive to aluminum toxicity

• Autor(a) principal: Oliveira,Érica Cristina de
• Data de Publicação: 2017
• Outros Autores: Pinto-Maglio,Cecília Alzira Ferreira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Bragantia
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052017000400456
• topic: Triticum aestivum; Triticum turgidum ssp. durum; karyotype; CMA/DAPI banding; FISH-rDNA; cytomolecular mapping

ABSTRACT Karyotyping and chromosome complement knowledge are a prerequisite for cytogenetic mapping. The aim of this study was to characterize 1 common wheat cultivar (BH 1146) and 4 durum wheat genotypes (IAC 1003, Langdon, P19 and P33) from the breeding program of the Agronomic Institute of Campinas (IAC), using karyotype analysis together with Chromomycin A3/4’-6-Diamidino-2-phenylindole (CMA/DAPI) banding techniques for longitudinal characterization of chromosomes and fluorescence in situ hybridization (FISH) in the mapping of the 45S rDNA region. Durum wheat chromosome complement number was 2n = 4x = 28 with the following karyotype formula: 22m + 6sm. Common wheat chromosome complement number was 2n = 6x = 42 with the following karyotype formula: 34m + 8sm. Tetraploid and hexaploid genomes presented 2 pairs of chromosomes with secondary constriction and terminal satellites. All 5 wheat genotypes exhibited CMA and DAPI bands and signals in the 45S rDNA regions (FISH-probe pTa71) which varied in number and location on the chromosome complement. All lines showed greater amount of DAPI bands than CMA bands. The FISH-rDNA 45S in situ hybridization signals, related to the nucleolar organizing regions (NORs), were observed in common wheat, presenting signals for the 45S rDNA sequence in 3 pairs of chromosomes. Durum wheat presented signals in 2 pairs. The CMA bands coincided with the location of 45S rDNA region in the chromosomes of durum wheat. The techniques were efficient for chromosomal characterization of all 5 genotypes.