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Updated: May 29, 2026

A PCR-based Genotyping Method to Distinguish Between Wild-type and Ornamental Varieties of Imperata cylindrica
Published on: February 20, 2012
Intergenic spacer length variants in Old Portuguese bread wheat cultivars
Ana Carvalho1, Henrique Guedes-Pinto, José Lima-Brito
1Institute of Biotechnology and Bioengineering, Centre of Genomics and Biotechnology,University of Tras-os-Montes and Alto Douro, PO Box 1013, 5001-801 Vila Real, Portugal.
Abstract:
The intergenic spacer of the ribosomal DNA is highly variable, but is location specific in the nucleolar organizer region of the chromosomes. This study provides an event of high level of polymorphism / size variation and occurrence of 14 unique phenotypes in 48 landraces of Portuguese bread wheat cultivars for IGS-amplified products obtained by PCR-RFLP technique performed with TaqI. The attendant IGS polymorphism has been used to deduce affinities between landraces. Some of the high molecular weight IGS allelic variants were also probed for their chromosomal localization by sequential silver nitrate staining and fluorescence in situ hybridization. However, only the intergenic spacer allelic variant of 3.1 kb could be successfully hybridized, and was observed to be physically located on the chromosome pair 1B in the NOR loci of the cultivar 'Magueija'.
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