genomic composition of Tricepiro, a synthetic forage crop

• Published in: Genome Vol. 48; no. 1; pp. 154 - 159
• Main Authors: Ferrari, M.R, Greizerstein, E.J, Paccapelo, H.A, Naranjo, C.A, Cuadrado, A, Jouve, N, Poggio, L
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.02.2005; Canadian Science Publishing NRC Research Press
• Subjects: Biotin; Chromosomes; Chromosomes, Plant; Crops; cytogenetic analysis; Deoxyribonucleic acid; DNA; DNA probes; Edible Grain - genetics; Fish; Fluorescence in situ hybridization; Forage crops; forage grasses; Genome, Plant; genomic in situ hybridization; Genomics; Hybridization; hybrids; in situ hybridization; In Situ Hybridization, Fluorescence; intergeneric hybridization; Mitosis - genetics; Probes; Secale; Thinopyrum; Thinopyrum ponticum; triticale; Triticum; Triticum aestivum; Wheat
• ISSN: 0831-2796; 1480-3321
• DOI: 10.1139/g04-081

Chromosome in situ hybridization (FISH and GISH) is a powerful tool for determining the chromosomal location of specific sequences and for analysing genome organization and evolution. Tricepiro (2n = 6x = 42) is a synthetic cereal obtained by G. Covas in Argentina (1972), which crosses hexaploid triticale (2n = 6x = 42) and octoploid Trigopiro (2n = 8x = 56). Several years of breeding produced a forage crop with valuable characteristics from Secale, Triticum, and Thinopyrum. The aim of this work is to analyse the real genomic constitution of this important synthetic crop. In situ hybridization using total DNA of Secale, Triticum, and Thinopyrum as a probe (GISH) labelled with biotin and (or) digoxigenin showed that tricepiro is composed of 14 rye chromosomes and 28 wheat chromosomes. Small zones of introgression of Thinopyrum on wheat chromosomes were detected. The FISH using the rye repetitive DNA probe pSc 119.2 labelled with biotin let us characterize the seven pairs of rye chromosomes. Moreover, several wheat chromosomes belonging to A and B genomes were distinguished. Therefore, tricepiro is a synthetic hexaploid (2n = 6x = 42) being AABBRR in its genomic composition, with zones of introgression of Thinopyrum in the A genome of wheat.