Cytogenetics of four telotrisomics in barley (Hordeum vulgare L.)

Four barley telotrisomics (Triplo 3S, 5S, 6S, and 7S) were studied. No major qualitative differences in morphology between the telotrisomics and their diploid sibs were found. The pollen and seed fertility of these telotrisomics was comparable to their diploid sibs. The meiotic study showed that the average frequency of 6II + 1III at diakinesis and metaphase I was 84.2% and 71.7%, respectively. The normal chromosome separation ranged from 77.2% to 89.4% at anaphase I through telophase II. The transmission rate of the extra telocentric chromosomes averaged 28.4% upon selfing and 28.7% through the female. All four telotrisomics showed various degrees of pollen transmission, the average being 3.6%. Ditelotetrasomic plants (2n = 14 + 2 homologous telocentrics) were obtained in the progenies of selfed monotelotrisomic plants of all four types. These ditelotetrasomic plants were viable and showed various degrees of seed fertility.