Cytological analysis of hybrids among triticales and trigopiros

MAIA FRADKIN, EDUARDO GREIZERSTEIN, HÉCTOR PACCAPELO, VÍCTOR FERREIRA, EZEQUIEL GRASSI, LIDIA POGGIO AND MARÍA ROSA FERRARI

GENETICS AND MOLECULAR BIOLOGY

SOC BRASIL GENETICA

Lugar: Brasil; Año: 2009 vol. 32 p. 797 - 801

1415-4757

We studied three different tricepiros: (Don Santiago x Don Noé), (Cumé x Horovitz) and (Cumé x Don Noé). Thetricepiro (Don Santiago x Don Noé) was obtained by crossing the triticale Don Santiago INTA (AABBRR, 2n = 6x = 42)with the trigopiro Don Noé INTA (AABBDDJJ, 2n = 8x = 56). The number of chromosomes for the F1 was 2n = 49, themost frequent meiotic configuration being 14 bivalents and 21 univalents. The univalents were situated in the peripheryof the equatorial plane, whereas the bivalents were located in the central zone. The chromatids in some of theunivalents split when bivalents underwent reductional division in anaphase I. There were few laggard chromosomesor chromatids at this phase. The number of chromosomes (2n = 48-58) was high and variable, and the number of bivalentsper cell (18-23) also high in F3 individuals. In all F8 tricepiros (Don Santiago x Don Noé), F12 tricepiros (Cumé xHorovitz) and F12 tricepiros (Cumé x Don Noé), the number of chromosomes (2n = 42) was the same, these retainingthe rye genome, as demonstrated by GISH and FISH. These new synthesized allopolyploids constitute interestingmodels for investigating the evolutionary changes responsible for diploidization, and the chromosomal and genomicre-ordering that cannot be revealed in natural allopolyploids.Key words: hybrids, meiosis, tricepiro, univalents, reductional division.