Aminopeptidase B1: a centromere marker for chromosome 6B of wheat

Recombination values between the centromere, Amp-B1, and Lr3 were evaluated using a 'Chinese Spring' double-ditelosomic line for chromosome 6B and the euploid variety 'Sinvalocho M.A.'. Recombination was not observed between the centromere and Amp-B1, but between the centromere and Lr3 the value was 52.8 ± 3.74%. A particular progeny during two successive backcross generations showed abnormal behaviour that resulted in a reduced number of recombinants between the centromere and Lr3, probably a consequence of the karyotypic instability of 'Sinvalocho M.A.'.Key words: wheat genetic map, aminopeptidases, rust reaction, centromere marker.

THE IDENTIFICATION AND MEIOTIC BEHAVIOR OF A DITELOSOMIC LINE IN AVENA SATIVA L

A ditelosomic line was crossed with 12 identified monosomics. The metaphase I pairing was studied in the 40 + t – chromosome progenies. The telocentric chromosome was found to be homologous to the three previously identified monosomics namely, −7, −10, and −20 suggesting that the same chromosome is missing in all three lines. None of the chromosomes in monosomic condition used in the crosses except ST-7 and ST-17 from A. byzantina were involved in the reciprocal translocation present between Sun II and Garry and Rodney.The gene for normal vs. abaxial curling of the leaves was located on the short arm of chromosome 20. The genes for diploidisation and normal vs. kinky neck were located on 20L.